Big thanks again to David Midkiff, owner of DM Cycles for doing the boring on my cylinder. If you guys need any work done to your machines call Dave: Phone: 573-883-0203 Email: dmcycles09@yahoo.com Facebook: facebook.com/dmcycles09 Thank you for subscribing and continuously watching my videos! Instagram: 2_vintage_
Minimum oil ratio should be 32:1 Im pretty sure 40:1 is a bit lean expecially for a big bore cylinder alot of area to cover. Put High test gas in at least 93 but if u can get 100 would be the way to go with that high of compression otherwise it will detonate and pit the top of piston. But also piston will expand in height when up to temp and high rpm
On a bike like that it's 32:1 is probably required if he gets his squish right he should have 180 to 200 lb compression which doesn't tell you if you need high octane fuel or not obviously you would need high octane with that compression but you really need to know your compression ratio to know what octane fuel you should run if he can get his ratio under 12.5:1 then he should be able to just run high test pump fuel
@@noidontthinksolol the only problem with trying to run another piston from a 500 and the LTR 500 motors is they have those thrust washers on the sides of the wrist pin bearing now if you use a piston out of an rm500 then you can do away with the thrust washers but that's the only real other piston you could use you would really have to do some measurements first to make sure that the whips between the pin boss is wide enough to accept the rod and the wrist pin bearing
@@noidontthinksolol it's only with the lt250r and the lt500r for whatever reason Suzuki decided to use thrust washers but if you use the piston out of an RM 250 then you can remove the thrust washers
I have a Cr 500 that I bought in boxes. The cylinder with the bike had been re-sleeved and had been machined at the base too much and had the same problem as you. So I made a 2 mm base plate out of ally sheet ( same shape as gasket) and used 2 base gaskets either side of it. Worked fine and has been on bike 10 years. Also take into consideration that the rod will lengthen with heat and high revs while in use so always best too have more squish than less. Great build, best of luck.
If it was the base they fly-cut you need to be careful how much u increase that plate by, cause any Xtra or lesser height will disrupt your port timings...and that will screw with your performance big time
I'm a 4stroke engine person myself, but am learning so much about 2stroke engines and just how much the 2stroke engine relies on correct fuel ratio and proportion by watching your amazing videos !! Thankyou
I created my own spacer between the crank and cylinder with a sheet of 5052 aluminum 1.5mm thick. Outlined the gasket and cut it out with a dremel. Took about 3 hours to get it done. Used soldier wire to check the head piston clearance. Got it perfect.
@@2vintageHad the outer edge of piston to head clearance about 1.4mm. That was on a 2 stroke 300cc air cooled Polaris Xplorer motor. You could get away with 0.8mm...
Glad you had a great experience dealing with the folks at DM Cycles.👍🏼 Good customer service is so important. I just smile seeing you performing tasks a top your sweet work bench.👊🏼
You can adjust the squish by using different thickness base gaskets, or stacking them if you need to. Use sealer between each gasket. Also, When they told you to wash the cylinder in soapy water, they meant actually scrub the cylinder wall with a plastic brush or something similar. Not dunk the parts and call it good. The point is to get any embedded small cast iron particles out of the cylinder wall that's left over from machining. Same for the piston. You should also wipe out the cylinder walls vigorously with automatic transmission fluid and paper towels after its washed with soap and water. The towels will come out with gray iron on them guaranteed. And oil every single part and piece when you assemble them! If it moves it needs oil.
@@vwjd77 yes, definitely. It is necessary to remove fine iron particles embedded in the cylinder bore from machining it. You should scrub it with a brush and then a cloth in hot soapy water, the bore that is. Dry it completely and then use paper towels and automatic transmission fluid and wipe the cylinder out vigorously and repeatedly until no more gray color appears on the towels. If that's not done it will become embedded in the new rings and piston upon start-up and waste the new parts way too soon.
When you have it bored out two or three sizes bigger sometimes you need to have the head sent out to have the combustion chamber matched to the size of the piston it's not a common thing that happens usually you're all right as long as you don't go major overbore
Hope you plan on decking this engine before running. Squish, decking, gasket thickness, head gasket Inner diameter, spark plug gap, fuel to run and oil mix ratio, so many things needs to be figured out by a builder to be able to run this reliably. I own two quadzilla quads and I let my builder figure these things out, and I just follow what they tell me afterwards. Saves me money and keeps my machines running 👌🏼
That's already his problem the cylinder has been decked too many times and now that's why the piston is having a positive deck height normally you want a zero deck height now all he would need to do to really correct the problem and if he's going to keep the bike is run a cool head because then you can have a dome custom cut for that motor so your squish will be perfect and you won't be having the piston hitting the head it's all caused by the cylinder being decked too many times it doesn't have an incorrect rod in it it doesn't have an incorrect piston all that is fine the issue is the cylinder has been decked either too many times or someone has taken too much off it at one time
@@Johnbruzzi4234 of course it's above his skill and knowledge that's why he should just talk to someone who does cool head would be the best solution but doubling up the base gaskets can also be a solution
And it blew up in one minute of running on start up . Sad 😔 No history of any work done over last 30some years Of use abuse and blow up / rebuilding . Cool head great idea will cure the problem
With the piston coming up out of the cyl 2mm as you said it probably has had a stroker crankshaft installed in in it and will require a equally thick spacer under the cyl to keep the piston at the correct height
It could be a 2 mm stroker or a 2mm longer rod. I ran a ktm 132mm rod on my my cr250 and I had a 4.5mm stroke. And everything has to be dun the right way. You need to buy a cool head and the proper Dome
@@250race using a longer rod still means you would either have to use a different piston (shorter) or raise the cylinder to keep correct piston height and port timing using a longer rod let's the engine spin quicker an makes more hp higher rpm but you lose low rpm hp an torque
@@lawerncemiller6557 Never said it did. read what I wrote. On at Cr250 is 72 stroke I had a 76.58. So I'm 5.65 mms over stock stroke. Stock rod is 126 mms I went with a 132mm rod. 67mm piston is right at 269.5 or so.
@@lawerncemiller6557 Ok bro I have .188 space plate with 2 gaskets. At .018 ×2 A .130 deep step dome. DBY cool head. 67mm piston jug cost $1000 Came from DBY power sport the king of micro racing And I all so have a $650 Billet Bam crank. And yes it does rev up fast and yes it. Gave it 1 more up From the TXR rod at 128mm And I all run a crf 450 coil 2002 to 2008 this also gave me 1.5 more HP over the KZ4 2000 or 2001 ignition And my motor turns to 1080 RPMs
That's a bummer joe no doubt you will find a good solution to overcome the problem at least you are on the right page mate would be devastating to put all the work into it for it to blow up again good luck and take care 🔧🔧👍👌🔧
When u ride a big bore 2 stroke anything u short shift it and let it eat. Riding them wound tight is out of the sweet spot in them. 80cc & 125cc u have to stay on the pipe (revved up or wound up) but the bigger ones u get more power from bottom end to low top end.
Check squish clearance first. If it’s to small raise the cylinder with a base gasket. But first check the ports at BDC bottom dead center and make sure the piston is just below the exhaust port and just above the intake. You’ll figure it out no biggy
Double or triple up the cylinder base gasket or use a thicker gasket until it gives you the right amount of clearance I had to do this on a few snowmobiles and 4 wheelers
No it never had the wrong Rod put in it the reason that you're showing positive deck height is most likely the cylinder has been decked once or twice to reflatten the surfaces and what happens is eventually it will be just enough to touch the head all you need to do is run a thicker base gasket or run a cool head
I know you'll figure this out, you got this Joe! Another great build from you, can't wait to see this best run again! Awesome job on noticing the piston was going to far I bet the last guy shaved the head an didn't tell you! Add another base gasket an you should be alright!
Hey joe I just picked up a 1991 honda 250x and it's got a dg slip on and I was wondering what I should run for jets beacuse when its warm it idles high but when it's cold it wont idle and you have to hold the gas
i have a 2006 trx450r i recently picked up. did the same thing. my fix ultimately ended up being incorrect float height. i would say make sure the carb is 100% dialed before you go messing with jet settings. If the carb isnt setup properly the jetting is just going to compensate for a bigger issue. So clean the jets, all of the passeges, behind the afr screw and idle screw, really just everything. and set the float height to the factory spec. and then jet from there
That’s why you buy the right tool and check the squish and deck height with the proper guage so you know how thick of a gasket or gaskets you need to use but you should already know that since you build these bikes all the time. That way your not just winging it and hope it doesn’t blow up
Rule of thumb every moving part that is metal on metal I always use Lucas break in procedure oil or at least use Lucas assembly lube on all metal to metal moving parts
It had already been suggested a fair few times, but what I would do is run a base plate that matches the difference in deck height. Maybe it this was missed out when the previous owner built it? Best of luck 👍🏼
I want to add: With the head not overbored to the same diameter as the piston/cylinder the piston crown hits on the outside .020" or so, locks the rings, the stuck rings jam the piston randomly against the cylinder wall depending on forces and scores/melts things.
Just finished watching the full video, that’s a strange one dude. Just a thought, can you not get a thicker base gasket? Should lift the cylinder slightly?
My 1989 LT500RK wasn't like that. But she was a beast and make sure you have those Jets right because that kick start kick back will put your knee right into the handle bars. One time I went to go kick that Zilla put that Kickstart right through the bottom of my boot
several of the The dirffereamce between the top of cylinder and he top of the piston is called the deck height and most of the European bikes of the 70 and 80's were designed to have an adjustable. deck height. they came with several different thickness of base gasket so that you could change the power of the motor by adding or subtracting base gaskets. example: race bikes had very high compression where a trail bike had a little less compression. It made it a little more manageable especially in tight woods. If someone shaved the surface of the center cases because they were a bit warped then that would explain the difference you are seeing. adding an additional base gasket is not that big of a deal but as you have discovered the use of a permatex or such can really help to keep it all together, best of liuck.
Bore the combustion chamber diameter in the head to the same overbore diameter as the cylinder/new piston size or the outer edge of the piston will hit the head and lock the rings. The previous owner may not have done this either. I don't know if this is your problem but I've seen it happen on an overbored 2017 yz250 with the exact same problem of locked rings on a new topend. It was hard to notice any damage on the top of the piston if you didn't know it was there. Like I said just another thing to consider.
Great video, I would of put another base gasket so that the piston dosent go past the top of barrell. KTM.380 comes with 3 base gaskets to get the correct TDC
In my opinion this is why when you rebuild a engine you need to measure everything at this point with the super high compression I'm not shure but it could be a stretched rod I would want to know if when it was rebuild the last time if the rod was replaced? It's hard to tell without a blueprint check list with all the measurements wrote down .
i'd get an o.e rod and bearings and start there lol i'm putting my money on stretched rod from when it jammed up cuz it full on locked up, if it made enough heat to seize a piston until it cooled off it most deff stretched a rod, not only are you making heat from lean running your making even more heat from friction because lean in a 2 stroke means less lubrication too. it was probly stretching as your were riding and when it jammed up was the final blow it seems to be the obvious culprit. i'd look up stock rod dimentions and measure the one in it or just replace it all together before going bill nye with double gaskets lol. plus when you look at the piston when its above the deck at 26:10 it's not even all the way around, the wrist pin is slightly tweaked look at the piston gaps it's super tight on the right side and looks wider on the left.
you have used the thinnest base gasket so your cylinder is sitting lower . increasing your head gasket thickness will alter your squish but mess up your port timing. measure your sqyuish to avoid this. i reckon that has been worked on in the past and is running minimum squish
You might need to put a fatter base gasket on. See what the ports are like see if the piston matches with the ports may need to raise the whole cylinder
I still hope there is no debris in the bottom end, and that the seals weren't the cause, or one of the causes, to your blow-up, or it will just blow up again. The quadzilla has a terrible squish setup OEM. If the squish gap is too large, like OEM, it has a much HIGHER chance of detonating than if it's a little too small. Did you replace those wrist pin thrust washers? Good practice every time the cylinder is off. They like to fracture and make a big mess of things. You don't necessarily NEED the billet aluminum ones and narrower wrist pin bearing, but you should at least buy the ones off the 88-92 LT250R. They have a smaller ID, so they rattle much less on the wrist pin, and that means much less chance of initiating a fracture after some hours of use. Good call on the base gasket pookie, although you didn't have to put it on the exhaust side, just the transfers and boost areas are sufficient. Putting it on the top side of the gasket too will ensure no blowouts. Also, the clutch lever is on upside down. Bigger base fasteners take 29 ft-lbs, the smaller ones take 8.5 ft-lbs. Also, the studs should be put in the cases and head by themselves and tightened, not with the nuts. Did you clock the head gasket correctly? Little holes go over the exhaust port. The head nuts should be tightened to 18 ft-lbs, or the head might warp and cause a coolant leak. 87s are known for this. Bigger head studs don't help, as it's the head that flexes, Not the studs. I thought I saw the piston sticking up past the cylinder. THAT will make the squish gap too small! A non big bore head gasket will hit the piston too. Obviously, someone decked this cylinder way too much at some time. You need to see how the crown of the piston lines up with the floors of the ports. It the piston sticks into the port height wise, you need 1 or more additional base gaskets. If the piston lines up with the floors, you need a non-cut head and/or a thicker head gasket, depending on your squish test. It's not the wrong rod. No other rod would work. The closest rod length wise is the CR500R rod, which is 1mm longer, but too many other things won't let it be used in an LT. If the piston doesn't hit the old head gasket when you turn it over, the new head gasket is not a big bore head gasket. The thickness is not the problem. Measure the ID. The new head gasket is probably less than 88mm, and the old head gasket is more than 88mm. An OEM gasket won't help there. That's one problem solved. But the piston sticking out of the cylinder still needs to be solved The piston must have just touched the head gasket before. How much bigger are the holes in the head gasket than the head studs? If they are big holes compared to the head studs, the gasket must've been off center slightly. You probably shouldn't ride it until it's warmer. Jetting for the cold is a pain. Also, I'm sure the balancer is timed wrong.
Could it be a stroked motor with a OEM head? I came across a similar situation with a 2 stroke dirt bike years ago. I ended up going through phat head for a custom billet head. The only issue is figuring out the measurement for them to machine the new head. If that's your issue.
Hey just thought you could try getting some custom copper gaskets made for top & bottom of the cylinder? Known people have done this before to get round problems
Michael Agius, I think that depends more on the fuel you use because the manual actually calls for 20:1. However, fuels have changed since these engine were made along with what octane you run, could make a big difference. I read one post that said the user was running 110 octane so they were mixing 40:1. Definitely something Joe should research.
@@williamevans6468 what Micheal means is running oil at 20:1 will make air fuel mix lean if you do not adjust jetting bigger. The reason why 20:1 is leaner than say 40:1 is that more oil displacing fuel as mixture passes through jets makes it lean.
@@dannyarmstrong7659 I understand what you and Michael are saying. However, that engine was designed to run 20:1 off the showroom floor. So unless jetting was changed, in theory, there should be no reason to mess with that on a stock engine. With him putting a big bore kit on, that is where I would consider a change in jetting possibly and the first thing you would want to know is what fuel and oil mixture your going to be running with that change. From there you can look at changing the jetting as needed. I hope that clarifies what I initially was saying a bit better.
I've heard of people using warm/soft tootsie rolls to check squish. Leave them in the wrapper and warm them up to make the soft. I've never done it. Just wanted to share.
Good morning just watching some of vids today was curious if the a arms on your lt250r are aftermarket or not because they dont look like the arms on my 86 thanks! Keep up the good work!
Ken O'Connor racing can shave your head definitely or if you can find a stroker spacer plate, if the wrong rod was fitted all the ports will be slightly off I'm sure
Look man you need to invest in a Snap-On compression tester and a borescope so so you know you have good compression and you know your cylinder walls and your piston are in Tip-Top shape
That makes it run lean unless you go bigger on jetting. Never a good idea to run oil injection ans premix. Oil injections are extremely reliable when properly maintained.
@@dannyarmstrong7659 it was never a a Lot of oil it was just a little bit and he ran stock jetting and it ran perfect and started in 30 below zero weather but yes what you are saying is true if you where to run true premix
You have to add to the base and recutting the head maybe required but I’m betting you get away without having it cut just add to the base and get your squish to .020 .5mm at minimum
Just stack some base gaskets till the piston sets flat with the jug should work just fine I built a bit of stuff and never check how tight bolts or anything should be i just eyeball it always works out I mean I seen as soon as you put the jug on you was going to have that problem lol I seen it pop out and went wow not good almost was thinking you was going to blow it up again fr I always check my stuff but just with my eyes lmao but I only do small engines I like to be able to pick up the motor if need no stupid tools or lifts just some riches and time just how I like it
i would use 2 base/cyl gaskets. should be enough to get piston flush. piston is never supposed to be above the bore line. Avoid using 2 head gaskets. with that much power and compression, 2 stacked gaskets at the head would be asking for a blowout. should be fine at the base though! remember, More oil in the mixture is MORE LEAN
Big thanks again to David Midkiff, owner of DM Cycles for doing the boring on my cylinder. If you guys need any work done to your machines call Dave:
Phone: 573-883-0203
Email: dmcycles09@yahoo.com
Facebook: facebook.com/dmcycles09
Thank you for subscribing and continuously watching my videos!
Instagram: 2_vintage_
It’s crazy how you got your hands on piston rn cause I tried buying wiseco can’t find them no where they sold out mine is lt 500 87
Minimum oil ratio should be 32:1 Im pretty sure 40:1 is a bit lean expecially for a big bore cylinder alot of area to cover. Put High test gas in at least 93 but if u can get 100 would be the way to go with that high of compression otherwise it will detonate and pit the top of piston. But also piston will expand in height when up to temp and high rpm
On a bike like that it's 32:1 is probably required if he gets his squish right he should have 180 to 200 lb compression which doesn't tell you if you need high octane fuel or not obviously you would need high octane with that compression but you really need to know your compression ratio to know what octane fuel you should run if he can get his ratio under 12.5:1 then he should be able to just run high test pump fuel
@@noidontthinksolol the only problem with trying to run another piston from a 500 and the LTR 500 motors is they have those thrust washers on the sides of the wrist pin bearing now if you use a piston out of an rm500 then you can do away with the thrust washers but that's the only real other piston you could use you would really have to do some measurements first to make sure that the whips between the pin boss is wide enough to accept the rod and the wrist pin bearing
@@noidontthinksolol it's only with the lt250r and the lt500r for whatever reason Suzuki decided to use thrust washers but if you use the piston out of an RM 250 then you can remove the thrust washers
I have a Cr 500 that I bought in boxes. The cylinder with the bike had been re-sleeved and had been machined at the base too much and had the same problem as you. So I made a 2 mm base plate out of ally sheet ( same shape as gasket) and used 2 base gaskets either side of it. Worked fine and has been on bike 10 years. Also take into consideration that the rod will lengthen with heat and high revs while in use so always best too have more squish than less. Great build, best of luck.
If it was the base they fly-cut you need to be careful how much u increase that plate by, cause any Xtra or lesser height will disrupt your port timings...and that will screw with your performance big time
Put the mesh on fuel line Joe, it will help immensely. Great vid, great job!
I'm a 4stroke engine person myself, but am learning so much about 2stroke engines and just how much the 2stroke engine relies on correct fuel ratio and proportion by watching your amazing videos !! Thankyou
I created my own spacer between the crank and cylinder with a sheet of 5052 aluminum 1.5mm thick. Outlined the gasket and cut it out with a dremel. Took about 3 hours to get it done. Used soldier wire to check the head piston clearance. Got it perfect.
What was your squish clearance
@@2vintageHad the outer edge of piston to head clearance about 1.4mm. That was on a 2 stroke 300cc air cooled Polaris Xplorer motor. You could get away with 0.8mm...
Glad you had a great experience dealing with the folks at DM Cycles.👍🏼 Good customer service is so important.
I just smile seeing you performing tasks a top your sweet work bench.👊🏼
You can adjust the squish by using different thickness base gaskets, or stacking them if you need to. Use sealer between each gasket. Also, When they told you to wash the cylinder in soapy water, they meant actually scrub the cylinder wall with a plastic brush or something similar. Not dunk the parts and call it good. The point is to get any embedded small cast iron particles out of the cylinder wall that's left over from machining. Same for the piston. You should also wipe out the cylinder walls vigorously with automatic transmission fluid and paper towels after its washed with soap and water. The towels will come out with gray iron on them guaranteed. And oil every single part and piece when you assemble them! If it moves it needs oil.
This scrubbing you refer to, is this something that should be carried out on a 4stroke bike engine? Is it just good practice
@@vwjd77 yes, definitely. It is necessary to remove fine iron particles embedded in the cylinder bore from machining it. You should scrub it with a brush and then a cloth in hot soapy water, the bore that is. Dry it completely and then use paper towels and automatic transmission fluid and wipe the cylinder out vigorously and repeatedly until no more gray color appears on the towels. If that's not done it will become embedded in the new rings and piston upon start-up and waste the new parts way too soon.
When you have it bored out two or three sizes bigger sometimes you need to have the head sent out to have the combustion chamber matched to the size of the piston it's not a common thing that happens usually you're all right as long as you don't go major overbore
The beast has been woken, been waiting for this 🤘🏼
So nice to see a clean motor getting put together.... Looks good man very professional..
Hope you plan on decking this engine before running. Squish, decking, gasket thickness, head gasket Inner diameter, spark plug gap, fuel to run and oil mix ratio, so many things needs to be figured out by a builder to be able to run this reliably. I own two quadzilla quads and I let my builder figure these things out, and I just follow what they tell me afterwards. Saves me money and keeps my machines running 👌🏼
.050 to .060 is safe
That's already his problem the cylinder has been decked too many times and now that's why the piston is having a positive deck height normally you want a zero deck height now all he would need to do to really correct the problem and if he's going to keep the bike is run a cool head because then you can have a dome custom cut for that motor so your squish will be perfect and you won't be having the piston hitting the head it's all caused by the cylinder being decked too many times it doesn't have an incorrect rod in it it doesn't have an incorrect piston all that is fine the issue is the cylinder has been decked either too many times or someone has taken too much off it at one time
Lol that's way way above his skill and knowledge
@@Johnbruzzi4234 of course it's above his skill and knowledge that's why he should just talk to someone who does cool head would be the best solution but doubling up the base gaskets can also be a solution
And it blew up in one minute of running on start up . Sad 😔
No history of any work done over last 30some years Of use abuse and blow up / rebuilding .
Cool head great idea will cure the problem
I'm amazed with how much you get done in a video and how often you upload. Your on a mission to fix them all!! Great video, as usual. 🔥💪
With the piston coming up out of the cyl 2mm as you said it probably has had a stroker crankshaft installed in in it and will require a equally thick spacer under the cyl to keep the piston at the correct height
It could be a 2 mm stroker or a 2mm longer rod.
I ran a ktm 132mm rod on my my cr250 and I had a 4.5mm stroke.
And everything has to be dun the right way. You need to buy a cool head and the proper Dome
@@250race putting a longer rod in a engine doesn't change the stroke only the off-set of the crankpin on the crankshaft changes the stroke
@@250race using a longer rod still means you would either have to use a different piston (shorter) or raise the cylinder to keep correct piston height and port timing using a longer rod let's the engine spin quicker an makes more hp higher rpm but you lose low rpm hp an torque
@@lawerncemiller6557
Never said it did.
read what I wrote.
On at Cr250 is 72 stroke I had a 76.58. So I'm 5.65 mms over stock stroke.
Stock rod is 126 mms
I went with a 132mm rod.
67mm piston is right at 269.5 or so.
@@lawerncemiller6557
Ok bro
I have .188 space plate with 2 gaskets. At .018 ×2 A .130 deep step dome. DBY cool head.
67mm piston jug cost $1000
Came from DBY power sport the king of micro racing
And I all so have a $650 Billet
Bam crank.
And yes it does rev up fast and yes it. Gave it 1 more up
From the TXR rod at 128mm
And I all run a crf 450 coil 2002 to 2008 this also gave me 1.5 more HP over the KZ4 2000 or 2001 ignition
And my motor turns to 1080 RPMs
That's a bummer joe no doubt you will find a good solution to overcome the problem at least you are on the right page mate would be devastating to put all the work into it for it to blow up again good luck and take care 🔧🔧👍👌🔧
When u ride a big bore 2 stroke anything u short shift it and let it eat. Riding them wound tight is out of the sweet spot in them. 80cc & 125cc u have to stay on the pipe (revved up or wound up) but the bigger ones u get more power from bottom end to low top end.
Assymbly lube on power valve is good idea.great job Joe!
Ohhhh baby! That cynlder top down shot, yeah boy smoooooth🤘
still make sure you have adequate coolant circulation. your scorched piston is an overheat issue, coolant flow, bore too tight or lean on top end
Check squish clearance first. If it’s to small raise the cylinder with a base gasket. But first check the ports at BDC bottom dead center and make sure the piston is just below the exhaust port and just above the intake. You’ll figure it out no biggy
Double or triple up the cylinder base gasket or use a thicker gasket until it gives you the right amount of clearance I had to do this on a few snowmobiles and 4 wheelers
No it never had the wrong Rod put in it the reason that you're showing positive deck height is most likely the cylinder has been decked once or twice to reflatten the surfaces and what happens is eventually it will be just enough to touch the head all you need to do is run a thicker base gasket or run a cool head
I know you'll figure this out, you got this Joe! Another great build from you, can't wait to see this best run again! Awesome job on noticing the piston was going to far I bet the last guy shaved the head an didn't tell you! Add another base gasket an you should be alright!
Been waiting for this one
I had the same problem with a 86 kx125, I just used the 2 head gasket method and I have had no problems with it.
Hey joe I just picked up a 1991 honda 250x and it's got a dg slip on and I was wondering what I should run for jets beacuse when its warm it idles high but when it's cold it wont idle and you have to hold the gas
i have a 2006 trx450r i recently picked up. did the same thing. my fix ultimately ended up being incorrect float height. i would say make sure the carb is 100% dialed before you go messing with jet settings. If the carb isnt setup properly the jetting is just going to compensate for a bigger issue. So clean the jets, all of the passeges, behind the afr screw and idle screw, really just everything. and set the float height to the factory spec. and then jet from there
That’s why you buy the right tool and check the squish and deck height with the proper guage so you know how thick of a gasket or gaskets you need to use but you should already know that since you build these bikes all the time. That way your not just winging it and hope it doesn’t blow up
Rule of thumb every moving part that is metal on metal I always use Lucas break in procedure oil or at least use Lucas assembly lube on all metal to metal moving parts
You're the man brother keep it rocking
Double base gaskets to keep piston from coming higher than cylinder and then double for the head clearance. The end
It had already been suggested a fair few times, but what I would do is run a base plate that matches the difference in deck height. Maybe it this was missed out when the previous owner built it? Best of luck 👍🏼
I want to add: With the head not overbored to the same diameter as the piston/cylinder the piston crown hits on the outside .020" or so, locks the rings, the stuck rings jam the piston randomly against the cylinder wall depending on forces and scores/melts things.
Jug is gorgeous, sweet!!
Just finished watching the full video, that’s a strange one dude. Just a thought, can you not get a thicker base gasket? Should lift the cylinder slightly?
I looked around for a thicker base gasket and I can't find any place that specifically makes them thicker.
@@2vintage run two base gaskets
@@2vintage you can also have the head sent out and have it machined to accept the positive deck height
Been waiting for this Joseph. Haha thanks for the video
My 1989 LT500RK wasn't like that. But she was a beast and make sure you have those Jets right because that kick start kick back will put your knee right into the handle bars. One time I went to go kick that Zilla put that Kickstart right through the bottom of my boot
several of the
The dirffereamce between the top of cylinder and he top of the piston is called the deck height and most of the European bikes of the 70 and 80's were designed to have an adjustable. deck height. they came with several different thickness of base gasket so that you could change the power of the motor by adding or subtracting base gaskets. example: race bikes had very high compression where a trail bike had a little less compression. It made it a little more manageable especially in tight woods. If someone shaved the surface of the center cases because they were a bit warped then that would explain the difference you are seeing. adding an additional base gasket is not that big of a deal but as you have discovered the use of a permatex or such can really help to keep it all together, best of liuck.
Bore the combustion chamber diameter in the head to the same overbore diameter as the cylinder/new piston size or the outer edge of the piston will hit the head and lock the rings. The previous owner may not have done this either.
I don't know if this is your problem but I've seen it happen on an overbored 2017 yz250 with the exact same problem of locked rings on a new topend. It was hard to notice any damage on the top of the piston if you didn't know it was there. Like I said just another thing to consider.
Helll yeah Joe !!!
Put our jugs in Sonic after machining. Really makes them spakle... lol😅
More 2 stroke content 😁😁thanks so much
coolest Banzilla
use 2 base gaskets with gasket maker in between them. worked on my dads zilla 500 for years.
What about using molding clay or play dough in like a plastic sandwich bag for the squish test ?
bubble gum
soldered or pellets
On both sides of wrist pin.
.50 to .060 is safe.
That's a big piston
You should get a sled to fix up this winter
Yeah I might have to!
2vintage please do
you can double up a base gasket which will bring the piston flush with the cylinder top..
Great video, I would of put another base gasket so that the piston dosent go past the top of barrell.
KTM.380 comes with 3 base gaskets to get the correct TDC
Very very typical not un lucky lol! Should be pretty reliable after a fresh re build
add a extra base gasket to adjust the clearance
Sometimes you may have to use two base gaskets or have the cylinder squish band cut
did u think about a different base gasket
The piston hitting the head will have caused the ring groves in the piston to close up slightly .maybe what caused the problem in the first place
Been waiting for this creation to come back! #rocketship
I would try to reach out to Sabo. He'd definitely have answers for you
In my opinion this is why when you rebuild a engine you need to measure everything at this point with the super high compression I'm not shure but it could be a stretched rod I would want to know if when it was rebuild the last time if the rod was replaced? It's hard to tell without a blueprint check list with all the measurements wrote down .
That is a long way for a rod to stretch .
i'd get an o.e rod and bearings and start there lol i'm putting my money on stretched rod from when it jammed up cuz it full on locked up, if it made enough heat to seize a piston until it cooled off it most deff stretched a rod, not only are you making heat from lean running your making even more heat from friction because lean in a 2 stroke means less lubrication too. it was probly stretching as your were riding and when it jammed up was the final blow it seems to be the obvious culprit. i'd look up stock rod dimentions and measure the one in it or just replace it all together before going bill nye with double gaskets lol. plus when you look at the piston when its above the deck at 26:10 it's not even all the way around, the wrist pin is slightly tweaked look at the piston gaps it's super tight on the right side and looks wider on the left.
Don't forget about the base gasket. It may be safer to put a thicker gasket there. Good luck.
you have used the thinnest base gasket so your cylinder is sitting lower . increasing your head gasket thickness will alter your squish but mess up your port timing. measure your sqyuish to avoid this. i reckon that has been worked on in the past and is running minimum squish
Always use hondabond ht for base gaskets and intakes. Not permatex
You might need to put a fatter base gasket on. See what the ports are like see if the piston matches with the ports may need to raise the whole cylinder
I don't think I'd chance it without checking the clearance
Squish 101, adjust your squish with your base gaskets, there should be different thicknesses in the set?
I still hope there is no debris in the bottom end, and that the seals weren't the cause, or one of the causes, to your blow-up, or it will just blow up again.
The quadzilla has a terrible squish setup OEM. If the squish gap is too large, like OEM, it has a much HIGHER chance of detonating than if it's a little too small.
Did you replace those wrist pin thrust washers? Good practice every time the cylinder is off. They like to fracture and make a big mess of things. You don't necessarily NEED the billet aluminum ones and narrower wrist pin bearing, but you should at least buy the ones off the 88-92 LT250R. They have a smaller ID, so they rattle much less on the wrist pin, and that means much less chance of initiating a fracture after some hours of use.
Good call on the base gasket pookie, although you didn't have to put it on the exhaust side, just the transfers and boost areas are sufficient. Putting it on the top side of the gasket too will ensure no blowouts.
Also, the clutch lever is on upside down.
Bigger base fasteners take 29 ft-lbs, the smaller ones take 8.5 ft-lbs. Also, the studs should be put in the cases and head by themselves and tightened, not with the nuts.
Did you clock the head gasket correctly? Little holes go over the exhaust port. The head nuts should be tightened to 18 ft-lbs, or the head might warp and cause a coolant leak. 87s are known for this. Bigger head studs don't help, as it's the head that flexes, Not the studs.
I thought I saw the piston sticking up past the cylinder. THAT will make the squish gap too small! A non big bore head gasket will hit the piston too. Obviously, someone decked this cylinder way too much at some time. You need to see how the crown of the piston lines up with the floors of the ports. It the piston sticks into the port height wise, you need 1 or more additional base gaskets. If the piston lines up with the floors, you need a non-cut head and/or a thicker head gasket, depending on your squish test.
It's not the wrong rod. No other rod would work. The closest rod length wise is the CR500R rod, which is 1mm longer, but too many other things won't let it be used in an LT.
If the piston doesn't hit the old head gasket when you turn it over, the new head gasket is not a big bore head gasket. The thickness is not the problem. Measure the ID. The new head gasket is probably less than 88mm, and the old head gasket is more than 88mm. An OEM gasket won't help there. That's one problem solved. But the piston sticking out of the cylinder still needs to be solved
The piston must have just touched the head gasket before. How much bigger are the holes in the head gasket than the head studs? If they are big holes compared to the head studs, the gasket must've been off center slightly.
You probably shouldn't ride it until it's warmer. Jetting for the cold is a pain.
Also, I'm sure the balancer is timed wrong.
All you need to know 2vintage, right here!
@@rafaelcordova6374 Thank you!
@@titletownclowns1545 Thanks again Pops!
Diameter of head gasket the metal insert could be hitting the piston mic inside bore on all head gaskets
Could it be a stroked motor with a OEM head? I came across a similar situation with a 2 stroke dirt bike years ago. I ended up going through phat head for a custom billet head. The only issue is figuring out the measurement for them to machine the new head. If that's your issue.
Jug to case gasket to thin?
Never seen this problem and I could be way off but maybe a thicker head gasket would make the clearance
Have you looked into the polaris outlaw 525 irs with the ktm moter? And if so would you do one on the channel?
got a 400ex needing a top end waiting on the videos of the niche 440kit👍
Damn dude that head gasket ordeal… I hope this thing runs
Hey just thought you could try getting some custom copper gaskets made for top & bottom of the cylinder? Known people have done this before to get round problems
Check the thickness of the basic gasket some bike have more like my ktm hade 3 basis gaskets
Great video
4 corner seized. Aka cold seize. Previous owner didn't let it warm up properly before ripping on it.
Be careful running 20:1 . This will cause a lean mixture as the fuel will be thicker with oil.
You will need to adjust your jetting to compensate
Michael Agius, I think that depends more on the fuel you use because the manual actually calls for 20:1. However, fuels have changed since these engine were made along with what octane you run, could make a big difference. I read one post that said the user was running 110 octane so they were mixing 40:1. Definitely something Joe should research.
@@williamevans6468 what Micheal means is running oil at 20:1 will make air fuel mix lean if you do not adjust jetting bigger. The reason why 20:1 is leaner than say 40:1 is that more oil displacing fuel as mixture passes through jets makes it lean.
@@dannyarmstrong7659 I understand what you and Michael are saying. However, that engine was designed to run 20:1 off the showroom floor. So unless jetting was changed, in theory, there should be no reason to mess with that on a stock engine. With him putting a big bore kit on, that is where I would consider a change in jetting possibly and the first thing you would want to know is what fuel and oil mixture your going to be running with that change. From there you can look at changing the jetting as needed. I hope that clarifies what I initially was saying a bit better.
I've heard of people using warm/soft tootsie rolls to check squish. Leave them in the wrapper and warm them up to make the soft. I've never done it. Just wanted to share.
That's a cool idea lol
@@2vintage that's an old school hot rodders trick.
That old gasket has already been banged to shit and self clearances itself
Good morning just watching some of vids today was curious if the a arms on your lt250r are aftermarket or not because they dont look like the arms on my 86 thanks! Keep up the good work!
my ktm 300 came with multiple bottom cyclinder gaskets to do the quench
Ken O'Connor racing can shave your head definitely or if you can find a stroker spacer plate, if the wrong rod was fitted all the ports will be slightly off I'm sure
Look man you need to invest in a Snap-On compression tester and a borescope so so you know you have good compression and you know your cylinder walls and your piston are in Tip-Top shape
hopefully it blows up again!!!!!!
How it was just done ? And the same way ! How?
Go to rectification a cilynder head and go 🚀🚀🚀
My dad always ran mixed gas in his snowmobile even with the oil injection, he always said he'd rather foul a plug then lose a piston.
That makes it run lean unless you go bigger on jetting. Never a good idea to run oil injection ans premix. Oil injections are extremely reliable when properly maintained.
@@dannyarmstrong7659 it was never a a Lot of oil it was just a little bit and he ran stock jetting and it ran perfect and started in 30 below zero weather but yes what you are saying is true if you where to run true premix
You need to ensure the head gasket you have will fit an 88mm bore and not be smaller cause you will have issues...bad issues
When we need work or entertainment we only call 2vintage garage haha jk
maybe a thicker base gasket?
You have to add to the base and recutting the head maybe required but I’m betting you get away without having it cut just add to the base and get your squish to .020 .5mm at minimum
You need to add an extra base gasket
350x update?
Crank seals could be bad also causing a lean issue
Sweet
Make sure to set the timing per service manual.
@2vintage tou should do a garage tour
Just stack some base gaskets till the piston sets flat with the jug should work just fine I built a bit of stuff and never check how tight bolts or anything should be i just eyeball it always works out I mean I seen as soon as you put the jug on you was going to have that problem lol I seen it pop out and went wow not good almost was thinking you was going to blow it up again fr I always check my stuff but just with my eyes lmao but I only do small engines I like to be able to pick up the motor if need no stupid tools or lifts just some riches and time just how I like it
Maybe the previous owner had the cylinder cut and didn't take notice that
Just A suggestion, get out make a copper head gasket and get a thicker base gasket. Not sure if you can use a copper base gasket or not?
Not your biggest issue but just like the LT your front tires are directionally backwards.
i would use 2 base/cyl gaskets. should be enough to get piston flush. piston is never supposed to be above the bore line. Avoid using 2 head gaskets. with that much power and compression, 2 stacked gaskets at the head would be asking for a blowout. should be fine at the base though!
remember, More oil in the mixture is MORE LEAN
I had a kx500 can I put on a Suzuki quadsport 230