Yes I was gonna suggest the same, I use that trick on vehicles all the time to find vacuum leaks. I’d spray it around the carb too, could be a crack in the intake boot or anything else, that’s a pretty old bike now.
Since re-jetting didn’t have much effect, I wouldn’t rule out electrical just yet. Just because the spark plug checker shows a plug is ok, that doesn’t mean the other components aren’t breaking down.
@@anthonyjacobs8773 I recently had a loose coil wire its more like a complete loss of power than a backfire then FULL power then no power, backfire etc. I've also had bad flywheel which was very similar to this.
I REALLY like that bike... I can see why the previous owner was frustrated with it. Like you, I would have started with the carb, but after seeing the air screw only turned out 1/4 turn and inspecting the carb, I would have checked the power valve. I would certainly check it before resorting to completely tearing down the engine because it has decent compression and visually everything looks good.
Agree 110%.. When you pulled the plug the first time and it was wet, I said pull the pipe and check for oil residue. I have had to clear out a CR 250R pipe by burning it out with a propane torch. It did the trick. Peace
And re pack the silencer!!! Every 20 hours is the spec in most manuals, the packing degrades and gets soaked with oil inhibiting the top end of the power band
Just wanted to say that I love the videos Joe. I am 15 and have always had a passion for working on these machines. I have 2018 Suzuki drz 125l and I enjoy upgrading it. Ive been consistent watching for a few years and have picked up on quite a few things🤙
I'd go with the power valve first only because I had this same exact issue with my '90 YZ 125. Turned out the mechanic reassembled the bike with the power valve backward. After fixing the issue, it was business as usual, with the bike revving out with zero hindrance.
Leak down test… that will narrow it down quickly. All the carb adjusting in the world won’t fix the issue if there’s an air leak. Good luck and keep up the great work and content.
Do a leak down test first and while doing so spray soapy water around the jb weld case repair. Check power valve for excessive carbon build up or possibly worn or broken power valve. Silencer may need cleaned and re packed. Clean up all ground contact points on the frame. Had a bike years ago with a bad port job done by a goon that acted just like this. Rule out the above mentioned before tearing it down. Good Luck! It’s a good looking bike!
@jakeowens1770 depends how bad it's leaking and he only tried one larger jet It's nothing to go to the hardware store and fab up a leak tester. Fresh rebuild should have it done every time. He's never done one in his life. It's necessary. You can't rule out something you haven't even checked. But I agree something could be going wrong in the power valves too. Might have to check lol
Just fought a similar battle on a 2000 KTM with a Keihin carb. Hours of swapping jets. Long story short, it was the carb. Found an OEM (not Chinese replica) and it instantly solved the problem.
Same with my yz125 2003 the carb was bad it had mukui junk so I bought lectron carb now it runs strong 💪 that an apex head its awesome best thing I did to the bike an new piston numura pistons are really strong 💪 I had wiseco burn up an melted ring mess up my cylinder so I been using numura pistons they are good
Never cared for the "95" purple. I had a new 94, which was gorgeous. Either way, this was a nice score on your behalf.👍🏼 With some patience, this bike will return a hefty sum at some point. Detail the hell out of it and keep it in the showroom condition that it is.
If this year still has the exhaust power ports, they might be carboned up and sticking. Definitely worth cleaning those and putting stock jets back in. Check the muffler packing too. I have a 1989 that I bought new. Still runs like a champ. Original everything if you can believe it. I love it!
Yep, agree on both possibilities. I've had the exhaust packing etc fall apart causing partial restriction with similar problems. I would have said the crank seals, but as seen, no signs visible.
@qacomputers3344 Still possible but I think his jetting would have made a difference (hidden the problem)... maybe...maybe not. Tough one. Clean the exhaust port power valves. It won't hurt and it might fix the issue.
Joe you finally bought a bike that stumped. You will never accept defeat. All your viewers know that. So I'm looking forward to your next video. I'm curious on what the bike needs to be done to correct the issue.
Read through all these video comments. Lots of great information. Here is another one, "Before you tear anything down, check the power valve. That's what it sounds like to me"
I know its not the crack seal. The bike would rev all over the place like high low tick overs takes ages for revs to drop down. Power valve or stator or coil, even a bad cdi
whats the diffrent between 250 - and 450 topspeed ? Iam 186 cm 150 kg and i didnt no is 250 enough power for my weight the bike is for fun and speeding and a bit enduro
Yeah, Id think your chasing your tail with the jetting, I suspect air ingression thru the crank seals or that crack in the crankcase... somewhere its getting in. These faults are real buggers to solve but great when you nail it. At least you can shut the garage door on it and dont have to ride it home. Have fun!!
Check the power valve see if the last owner played with the settings in the power valve. You can adjust it to open sooner or later on the cylinder there is a stamp that says H and L check to see the position.
Its really easy to check power valve operation too. Just remove the round cover on the left side and Rev the engine. The line on the end of the power valve shaft should move about 90* from low to high if I recall.
I do believe that dog spends his time stuck in kennel sad if u ask me, mine would of just hoped out the truck after we got home with the new toy, joe rarely includes Vinny…..
First thought when you pulled it off was the crank seals, they get hard and brittle after 20 years on a 2T. All that junk around the flywheel made me think it was blowing premix out on that side. I didn’t see any oil coming out the muffler so I don’t think it is the rhs seal. I guess it could be the power valve not opening.
2 stroke dirtbike go-to checklist for me when it comes to performance issues. *Jetting/Spark Plug *Reeds *Powervalve issue/dirty *Crank Seals -stator side will cause air to be. sucked in, causing lean condition. -clutch side will suck trans fluid into crank cavity making bike run very rich Usually one of these is always the cause, of a consistent performance issue. If it's intermittent, especially once warmed up, usually electrical. I see you touched these basis and took all the right steps.
Bogging. Hmm. I remember bogging on another bike, but I don't remember what was wrong. It is always interesting to go through the process of finding out what is wrong with the bike and fixing it. 🙂👍
Lol! I once worked on a bike a whole afternoon before I realized it had a sidestand switch preventing it from starting. I had the carbs off, plugs out, battery charging and all.
I have a 96 250 I have 178 main 55 pilot clip 3 from top air screw at quarter turns out runs great. I also have a 91 125 which had a similar bog as your bike tested everything changed stator cdi exhaust system crank seals and put a new pwk carb on her still had bog. Only thing left to change was coil and ht cap I changed them the bog was gone. Love your channel man hope this helps 🛵💨
I think it sounds more like electrical. I had a CDI go bad once that was doing the same thing. I doubt it would be the seals do to the idle is just fine and it's not burning motor oil. Of course it could be just a simple plugged pipe.
Check the power valves for sure, they need regular cleaning anyways. But my money is on a bad coil, it's breaking down at high rpm. If it had an air leak from that JB weld or flywheel side crank seal you'd think smaller main jet would make it worse. Looking forward to seeing the fix! Retired auto mechanic here but recently got into small engine stuff and enjoying the change!
my money is on crank seals (due to smoke on first start) or CDI/spark related. It is like the issue i get with water on spark boot/coil grounding out the spark an or if the old cr has power valves being stuck closed.
What a beautiful bike.. watch all your videos,well most of them. You have fixed so many bikes. I have learned a lot from u. You have probably been asked this a lot but do you keep most of them after you fix them and also have you came across a 85 Honda 250r ATC. Or one of my other favorites 200x. Keep doing your thing bro . Your videos are what I end my day with. Thank you
I've had this same exact problem with my 1990 Yamaha YZ 125. Turns out the mechanic put the power valve in backward. Once he fixed the issue, it revved out perfectly again.
My 89 CR250 had a very similar issue and it was the power valves not working correctly. The power valves are a different setup on this but it's worth looking into.
I had Honda of Troy build me a Brian Swink replica 1995 CR250 team bike. Thing was a beautiful. Was identical except that I had Pro Circuit suspension instead of the factor kits. The growl at full throttle in 3rd gear was amazing. The first day I had it i stepped off it on the left side in my garage with shorts on and the footpeg filleted my calf. Super sharp. Learned a lesson there. Took 20 stitches to close it completely up.
Since the bog is at the mid to upper RPM's only, It would likely be an obstruction in air flow. Check Power valves to make sure they are fully opening at the higher RPM. Also, make sure your pipe and muffler are clear.
I have Lernt sooo much from watching you over the past few years Joe! you have solved Almost Every problem there is. Thankyou :) - Could your problem have somthing todo with the Pipe?/Chamber clogged?
Another great video, you have more patients than me. I agree with checking exhaust and silencer. Also, you checked the needle jet but didn't check to see if it was the right one. One complaint you do a walked around every time when the unit is in the back of the truck then do another one on the ground, cut one out and will not have to skip forward to you when you are working on it in garage.
When the jetting wasn't having much effect I was back to thinking ignition. Maybe check the gaps in the magneto pickups, the magnets in the flywheel, coil resistance, ignition module, etc. I could see one of those having an RPM dependent failure, such that it works fine below a certain RPM but then breaks up at higher.
Vinny just called me and said...David please tell my owner...I am 1000% sure it is the ignition...CDI...coil...I don't want to be near the backfires..😊
95 with a stock silencer, check if it has the stock rivits still. May never have been repacked. Revs good in neutral but as soon as you load it up and put more flow i.e exhaust, its no good. Easy to cross this off the check list anyways. Love your work bro, keep it up.
yep, the same thing when I repair cast water lines,, drill a hole on each side of the crack, tap the pipe till the crack reaches the holes, then clamp it...
Its not the jetting. Could be bad cdi,Coil, stator, yes or power valve not opening. Its not crank seal. It would rev up n down very weird. Like revs stay high for long like running lean. My guess is stator as ive had this same problem and it fixed it. Also i tested the stator on multi meter and it was fine. Shop told me to replace it and promised me it would solve it. Well obviously it worked. Oh yeh ktm still suffering with this problem. That jb weld needs looking at tho. Im not convinced there is air sucking in by listening to the engine tho
Fought almost the same battle same bike. Needle was wore out, new one helped but emulsion tube(part of the body on the pwk) was smoked too. You could never get the jetting dialed. Always sounded like ignition was breaking up or it was going to foul a plug (never did). Swapped parts onto a extra carb body and it was golden.
Just had a bike with same symptoms. Chased the carb forever. Showed it to a pro mechanic friend, he told me to check the coil. That was it, I was shocked.
I thought it was rich but it wasn't but I also first thought PV at the first of the video, real fighter here. Been watching you're vid's forever and watched you turn into a top Tech!!!!!!
i have a 91 cr 250 and it seeps a little bit into the stator area , it runs like a champ , bike will pull wheelies on the power band alone in 5th , i weigh 160lbs .... cant wait for the full rebuild on this bike
I’d be checking the plug wires and coil. Plug boot. I like how you are checking the jetting but I don’t do it the same way. Wide open for the main jet. Half throttle for the needle jet. Just get your rpm’s up a tiny bit and adjust the air screw when it sounds crisp. More than a 1/4 turn on the air screw each way move pilot jet up or down so your in the desired range of 1 1/4-1 3/4 or whatever the manufacturer says is stock.
I just bought a 03 cr250 with bad bog! It ended up being the power valves were adjusted wrong. the servo motor wasnt opening the ports for mine at the right time. If this ytear has that motor, definitely worth checking! It still has the slightest bog at low rpm so i will be doing a carb tuning like this in the near future. great video, hope you find the cause on this bike, these things EAT!
I'm going with the power valve. Seen it before on the Honda. Also had a similar issue with a Cat snowmobile. Pretty much similar symptoms. Both were dirty/sticking power valves.
I once had a Yamaha 200 2 stroke 2 cylinder, as a boy of 14/15 year old, and at one point you had a mechanism on the ignition system with, when the engine made more rpm, the spark was made earlier by adjusting the moment that the points were opening. The ignition time was changing with more or less RPM. Now did I buy a complete little set and I just put it on, and the engine did run but did not have the higher rpm anymore. Same as with your bike. I also changed the carburetor, the exhaust pipes, and so on. He had more rpm when I made it leaner, but no power on the top.... I sold the thing before I found that. Then I got a Yamaha YZ250 from I think from around 1985, and there I got the same problem when I got trouble with the engine. The top of that Ignition changer was put on exactly the wrong way, so the ignition time didn't change but stayed the same all time. Again bought it in original parts of Yamaha and I think the did the same thing again: assembled it exactly wrong. I took the top of and turned it 180, so the time changed by more RPM and the problem was gone. It is a bit silly explained, but I am dutch and not very well know with the technical terms in English. I think it is about timing...
Joe just did a complete restoration on my 93 CR 250 the kehin pj carbs sometimes just go bad idk what it is did it to me on my 90 CR 125 aswell. Seeing the you can’t get a genuine kehin airstriker right now anywhere the best option for not spending a ton of money on a lectron or smart carb is order a Q&A carb for your bike from Rocky Mountain with a jd jetting kit for a air striker run the needle and main jet from the kit with the needle on the 4th spot down and a 60 pilot jet which doesn’t come in the kit the bike will run perfect. Literally took me a week to figure this out seeing that it wasn’t a genuine airstriker carb talked to a few TH-camrs about this and the pointed me in the same direction hope this helps in total your looking at about 130 bucks for the kit and carb.
Yea that sucks i had same problem yz125 2003 i changed all crank seals an i finally bought lectron carb an its fix it junk ass mukui carbs suck i love lectron carbs an apex head @@MrKawie1001
I have a suspicion the bog might have something to do with the JB Welded cracked engine case or a bad CDI Ignition or even a sheared off Woodruff key on the rotor/flywheel. Also check the ignition plug wire real good while running with the lights off and make sure it's not grounding out to the frame or engine. FYI I'm a 59 yr old FAA Certificated Airframe & Powerplant Mechanic since 1992 and have been repairing engines of many types from a young age approx. 7yrs old and I have 2 CR 500's for about 20yrs. 👍
Yeah check build-up in the expansion chamber....and look over the power valves. I'm thinking you'll find the answer in the power valves. Crank seals can def. effect tuning also though?
My favorite model Cr, awesome bike brother!! I wanna take time out as a real OG subscriber, and i want everyone to hit the like button for Joe his work ethic is unmatched
spray starting fluid where the JB weld is while holding the throttle at a steady RPM and see if it revs higher due to a leak and sucking air...
Yes I was gonna suggest the same, I use that trick on vehicles all the time to find vacuum leaks. I’d spray it around the carb too, could be a crack in the intake boot or anything else, that’s a pretty old bike now.
Great idea and quite honestly is a pretty easy fix to depending. A good TIG welder can button it up quick if it's not terrible
The intake doesn't suck air from the crankcase, Mr Mechanic.
@@tuberNunya youre trolling, a bad seal, or small crack in the case would cause a vacuum leak
If it was sucking in air then fatting the jets would have helped. He went all the way down to 130 and still same problem.
You beat me to another bike, had this one saved on Market Place myself and was pondering about purchasing. Awesome find and enjoy the videos.
Since re-jetting didn’t have much effect, I wouldn’t rule out electrical just yet. Just because the spark plug checker shows a plug is ok, that doesn’t mean the other components aren’t breaking down.
Excatly what I was thinking. Does that look like a tape job coming from the stator wire?
Cracked stator plate, throws it out of time at higher rpm, figured this out on a banshee, only after countless hours fukin with dual carbs....
I'm thinking the flywheel has gone bad. He needs to check if there is fuel in the exhaust. If so the ignition system is faulty.
@@anthonyjacobs8773 I recently had a loose coil wire its more like a complete loss of power than a backfire then FULL power then no power, backfire etc. I've also had bad flywheel which was very similar to this.
Before you tear anything down, check the power valve. That's what it sounds like to me.
first thing i thought
thats what i was thinkingtoo
Same!
Yep, gotta be the ol’ power valve. Free her up. (I have no idea, just agreeing)
I was thinking the same thing
Ol' Joe loves his dirt bikes. Nice looking cycle, a very popular/big seller, now let's tear it apart. Lots of teaching/learning moments
I REALLY like that bike... I can see why the previous owner was frustrated with it.
Like you, I would have started with the carb, but after seeing the air screw only turned
out 1/4 turn and inspecting the carb, I would have checked the power valve.
I would certainly check it before resorting to completely tearing down the engine because
it has decent compression and visually everything looks good.
This channel is like meditation for men!
Damn rite ay brother
F yeahhhhh with a Coors in each hand! Therapy !
brother!!
Need to light those 2 stroke scented candles to really feel the vibe!
Weird,
check pipe , to make sure there is no obstruction ! I had this issue with a 2001 cr250
Could bent places in pipe have caused an airflow restriction? Spark arrestor plugged?
@@DavidPhelps-du1mxdepends on where on the pipe its located
Agree 110%.. When you pulled the plug the first time and it was wet, I said pull the pipe and check for oil residue. I have had to clear out a CR 250R pipe by burning it out with a propane torch. It did the trick. Peace
And re pack the silencer!!! Every 20 hours is the spec in most manuals, the packing degrades and gets soaked with oil inhibiting the top end of the power band
@@Yz4Life fax
My buddy's yz 250 sounded like that, and to find out it was a partially clogged silencer.
Just wanted to say that I love the videos Joe. I am 15 and have always had a passion for working on these machines. I have 2018 Suzuki drz 125l and I enjoy upgrading it. Ive been consistent watching for a few years and have picked up on quite a few things🤙
Mid range bog=power valve sticking or misadjusted. Set the power valves up right and try a 170-175 jet. You should solve it that way.
Take your pick of which to tackle first:
1. Crank seal
2. Power valve
3. JB weld
I'd go with the power valve first only because I had this same exact issue with my '90 YZ 125. Turned out the mechanic reassembled the bike with the power valve backward. After fixing the issue, it was business as usual, with the bike revving out with zero hindrance.
3 first 2 second tear down 3rd
Could definitely be a sticking power valve or air leak.
Leak down test… that will narrow it down quickly. All the carb adjusting in the world won’t fix the issue if there’s an air leak. Good luck and keep up the great work and content.
definitely a crank seal i think, my 250r did the same thing.
I'm amazed at how many times you miss 2nd 😊
Every single time. It's like a trademark.
Do a leak down test first and while doing so spray soapy water around the jb weld case repair. Check power valve for excessive carbon build up or possibly worn or broken power valve. Silencer may need cleaned and re packed. Clean up all ground contact points on the frame. Had a bike years ago with a bad port job done by a goon that acted just like this. Rule out the above mentioned before tearing it down. Good Luck! It’s a good looking bike!
I've said that many times. It's critical to leak test 2 strokes. He's not once done one on video. Never
Word up on the power valves. Had that same problem. Don't think its vacuum case issue as the plug would be white
@@jakeowens1770 he has no idea what the plug is actually reading he didn't do a plug chop
@staygold902 if it had vacuum leak, it would run better with more fuel and higher main jet.
@jakeowens1770 depends how bad it's leaking and he only tried one larger jet It's nothing to go to the hardware store and fab up a leak tester. Fresh rebuild should have it done every time. He's never done one in his life. It's necessary. You can't rule out something you haven't even checked. But I agree something could be going wrong in the power valves too. Might have to check lol
Just fought a similar battle on a 2000 KTM with a Keihin carb. Hours of swapping jets. Long story short, it was the carb. Found an OEM (not Chinese replica) and it instantly solved the problem.
lol thats what you get for playing with chineseium
@@Skis878 Kei hin carbs from that era are 100% japanese tho
Same with my yz125 2003 the carb was bad it had mukui junk so I bought lectron carb now it runs strong 💪 that an apex head its awesome best thing I did to the bike an new piston numura pistons are really strong 💪 I had wiseco burn up an melted ring mess up my cylinder so I been using numura pistons they are good
Chinese 1s no good then brother?😬🤔😫😫👎👎👎🤝
Do a pressure / vacuum test to test the crank seals .
Never cared for the "95" purple. I had a new 94, which was gorgeous. Either way, this was a nice score on your behalf.👍🏼
With some patience, this bike will return a hefty sum at some point. Detail the hell out of it and keep it in the showroom
condition that it is.
I never understood the purple at all??
If this year still has the exhaust power ports, they might be carboned up and sticking. Definitely worth cleaning those and putting stock jets back in. Check the muffler packing too. I have a 1989 that I bought new. Still runs like a champ. Original everything if you can believe it. I love it!
Yep, agree on both possibilities. I've had the exhaust packing etc fall apart causing partial restriction with similar problems.
I would have said the crank seals, but as seen, no signs visible.
that's a good recommendation, I didn't think of that one,,, a good call,, but I still think its sucking air through the JB weld....hmmm?
@qacomputers3344 Still possible but I think his jetting would have made a difference (hidden the problem)... maybe...maybe not. Tough one. Clean the exhaust port power valves. It won't hurt and it might fix the issue.
@@poorsob
Do a crankcase leak down test, check power valves and check for exhaust restriction.
You know what's up! 👍
Agreed and if all else fails, try a new CDI black box
Joe you finally bought a bike that stumped. You will never accept defeat. All your viewers know that. So I'm looking forward to your next video. I'm curious on what the bike needs to be done to correct the issue.
video coming soon!
Man i'm stoked you're making this video. I have a 97 that has a similar problem. I replaced the right side crank seal with no improvement.
Just saw this comment a couple of lines below yours, "My buddy's yz 250 sounded like that, and to find out it was a partially clogged silencer"
Read through all these video comments. Lots of great information. Here is another one, "Before you tear anything down, check the power valve. That's what it sounds like to me"
I know its not the crack seal. The bike would rev all over the place like high low tick overs takes ages for revs to drop down. Power valve or stator or coil, even a bad cdi
Brilliant video Joe watching from Edinburgh Scotland UK 🇬🇧
I had a 93 same exact bike alot of good times on that machine!!
My favorite Cr250 eva had a huge picture on my wall when i was a lad best look Cr in my opinion lovly nice score mate
Check you harness grounds , ohm out your coil ..even cleaning your fly wheel an make sure it set right , I think its electrical
I will check
Pro circuit pipes work amazing on these bikes, I raced cr250’s from 1990 to 2008 the I switched to Yamaha 450’s
whats the diffrent between 250 - and 450 topspeed ?
Iam
186 cm
150 kg
and i didnt no is 250 enough power for my weight
the bike is for fun and speeding and a bit enduro
I would like to say the powervalve might be gummed up or not opening right. Great Vid!!!
Yeah, Id think your chasing your tail with the jetting, I suspect air ingression thru the crank seals or that crack in the crankcase... somewhere its getting in. These faults are real buggers to solve but great when you nail it. At least you can shut the garage door on it and dont have to ride it home. Have fun!!
Check the power valve see if the last owner played with the settings in the power valve. You can adjust it to open sooner or later on the cylinder there is a stamp that says H and L check to see the position.
Its really easy to check power valve operation too. Just remove the round cover on the left side and Rev the engine. The line on the end of the power valve shaft should move about 90* from low to high if I recall.
This was one of my all time favourite bikes I've owned.
It’s favorite 😊 this word is commonly misspelled
@@countrygaming8367 Both grammatically correct... just like color and colour.🙃
@@gableroux136 u took down countrygaming 😘
@@GoatedASF2K That's a victory in my book!
That is a VERY COOL spark plug tester!!! Never knew such a thing existed!
A walk around with our Vinny is just not right 😂
I do believe that dog spends his time stuck in kennel sad if u ask me, mine would of just hoped out the truck after we got home with the new toy, joe rarely includes Vinny…..
Power valve?
@@fordfan6474 We miss the Vinster!
@@fordfan6474I think Vinny may have gotten paddled and is on restriction 😅😂
Power valves or clocked exhaust
IMO it's pulling air from the crank seals. I would inspect the case for cracks because of J.B weld deal. Joe sweet bike overall 🎬🔥👍🫡
Learned about that issue from Jennies Garage
@@idahoduckhunter Big fan of Jennies garage myself 😎👍.
First thought when you pulled it off was the crank seals, they get hard and brittle after 20 years on a 2T. All that junk around the flywheel made me think it was blowing premix out on that side. I didn’t see any oil coming out the muffler so I don’t think it is the rhs seal. I guess it could be the power valve not opening.
2 stroke dirtbike go-to checklist for me when it comes to performance issues.
*Jetting/Spark Plug
*Reeds
*Powervalve issue/dirty
*Crank Seals
-stator side will cause air to be. sucked in, causing lean condition.
-clutch side will suck trans fluid into crank cavity making bike run very rich
Usually one of these is always the cause, of a consistent performance issue. If it's intermittent, especially once warmed up, usually electrical. I see you touched these basis and took all the right steps.
Did you check that ground where the frame was painted
Very nice bike. As for the issue noticed there's some pretty good suggestions already posted. Looking forward to seeing the outcome.
I reckon power valve sticking as its bogged hard at the beginning. I've had that happen to two yz 125's. If not could be the JB weld, or crank seals.
BIG FAN of the spark plug tester !!
Those spark checker can be a simple check but they have no combustion chamber pressure on them so don't rely on it completely or it can bite you
Bogging. Hmm. I remember bogging on another bike, but I don't remember what was wrong. It is always interesting to go through the process of finding out what is wrong with the bike and fixing it.
🙂👍
My 2002 did the same thing it was Servo for my ev power valve.
I would check that JB weld repair first see if air is leaking from engine
Lol! I once worked on a bike a whole afternoon before I realized it had a sidestand switch preventing it from starting. I had the carbs off, plugs out, battery charging and all.
Check the powervalve. The fact that 155 ran the best might indicate that that the jetblock gasket might be broken.
I have a 96 250 I have 178 main 55 pilot clip 3 from top air screw at quarter turns out runs great.
I also have a 91 125 which had a similar bog as your bike tested everything changed stator cdi exhaust system crank seals and put a new pwk carb on her still had bog. Only thing left to change was coil and ht cap I changed them the bog was gone.
Love your channel man hope this helps 🛵💨
I've dealt with that I'm in outboard business see it alot above 1/2 loses or weakens spark
Wow a CR! Nice 👍
I think it sounds more like electrical. I had a CDI go bad once that was doing the same thing. I doubt it would be the seals do to the idle is just fine and it's not burning motor oil. Of course it could be just a simple plugged pipe.
Love your show man beautiful Honda keeping ripping
Check the power valves for sure, they need regular cleaning anyways. But my money is on a bad coil, it's breaking down at high rpm. If it had an air leak from that JB weld or flywheel side crank seal you'd think smaller main jet would make it worse. Looking forward to seeing the fix! Retired auto mechanic here but recently got into small engine stuff and enjoying the change!
I would go for the crank seals, after checking the power valves
My first thought was power valves. Sweet looking bike! ‘93-‘95 are the best looking bikes Honda ever put out!
my money is on crank seals (due to smoke on first start) or CDI/spark related. It is like the issue i get with water on spark boot/coil grounding out the spark an or if the old cr has power valves being stuck closed.
What a beautiful bike.. watch all your videos,well most of them. You have fixed so many bikes. I have learned a lot from u. You have probably been asked this a lot but do you keep most of them after you fix them and also have you came across a 85 Honda 250r ATC. Or one of my other favorites 200x. Keep doing your thing bro . Your videos are what I end my day with. Thank you
I've had this same exact problem with my 1990 Yamaha YZ 125. Turns out the mechanic put the power valve in backward. Once he fixed the issue, it revved out perfectly again.
Mechanic)???? Lol
@michaelesposito6678 He was actually a great mechanic. If you don't make a mistake every now and then, you're not doing enough.
Good find.
@@stkyfngrszmooth as long as he fixed it that's great
My 89 CR250 had a very similar issue and it was the power valves not working correctly. The power valves are a different setup on this but it's worth looking into.
Love my 89CR250R great bike
Beautiful bike, you really find nice ones...
I had Honda of Troy build me a Brian Swink replica 1995 CR250 team bike. Thing was a beautiful. Was identical except that I had Pro Circuit suspension instead of the factor kits. The growl at full throttle in 3rd gear was amazing. The first day I had it i stepped off it on the left side in my garage with shorts on and the footpeg filleted my calf. Super sharp. Learned a lesson there. Took 20 stitches to close it completely up.
Since the bog is at the mid to upper RPM's only, It would likely be an obstruction in air flow. Check Power valves to make sure they are fully opening at the higher RPM. Also, make sure your pipe and muffler are clear.
👍
I have Lernt sooo much from watching you over the past few years Joe! you have solved Almost Every problem there is. Thankyou :)
- Could your problem have somthing todo with the Pipe?/Chamber clogged?
JB Weld on cranckcase is letting in air.
The higher the revs, the more it sucks in, the more lean the mix :)
That’s what I thought, JB weld is a clue for sure
Ding Ding Ding - I think that is the right answer
Another great video, you have more patients than me. I agree with checking
exhaust and silencer. Also, you checked the needle jet but didn't check to see if it was the right one.
One complaint you do a walked around every time when the unit is in the back of the truck then do another one on the ground, cut one out and will not have to skip forward to you when you are working on it in garage.
I had a 96 kx250 that ran identical to that. It ended up being the power valves not functioning properly
When the jetting wasn't having much effect I was back to thinking ignition. Maybe check the gaps in the magneto pickups, the magnets in the flywheel, coil resistance, ignition module, etc. I could see one of those having an RPM dependent failure, such that it works fine below a certain RPM but then breaks up at higher.
Vinny just called me and said...David please tell my owner...I am 1000% sure it is the ignition...CDI...coil...I don't want to be near the backfires..😊
Get a stock coil
Nothing sounds better than a two stroke dirt bike in my opinion, actually anything two stroke!
Yo, dude. What is up with your granddaddy’s GoldWing! Don’t leave me hanging. Please ASK ME ABOUT THE DIAMOND PLATES!
I been thinking the same thing
ive still been wondering about the tecate 3 he had.
95 with a stock silencer, check if it has the stock rivits still. May never have been repacked. Revs good in neutral but as soon as you load it up and put more flow i.e exhaust, its no good. Easy to cross this off the check list anyways. Love your work bro, keep it up.
If I had one a small hole would be much better than a crack, which will need drill at the ends to make sure it doesn't travel laterally.
yep, the same thing when I repair cast water lines,, drill a hole on each side of the crack, tap the pipe till the crack reaches the holes, then clamp it...
Its not the jetting. Could be bad cdi,Coil, stator, yes or power valve not opening. Its not crank seal. It would rev up n down very weird. Like revs stay high for long like running lean. My guess is stator as ive had this same problem and it fixed it. Also i tested the stator on multi meter and it was fine. Shop told me to replace it and promised me it would solve it. Well obviously it worked. Oh yeh ktm still suffering with this problem. That jb weld needs looking at tho. Im not convinced there is air sucking in by listening to the engine tho
a clean machine!...Thanks for the carb class...how about change the crank seal next...
Fought almost the same battle same bike. Needle was wore out, new one helped but emulsion tube(part of the body on the pwk) was smoked too. You could never get the jetting dialed. Always sounded like ignition was breaking up or it was going to foul a plug (never did). Swapped parts onto a extra carb body and it was golden.
Holy crap..Great deal on this bike..even if it has problems..vintage Hondas are hot commodities now .
Just had a bike with same symptoms. Chased the carb forever. Showed it to a pro mechanic friend, he told me to check the coil. That was it, I was shocked.
You got a great deal on that one!!!
This looks like a keeper. Sweet bike.
See what s up the JB weld.
IMHO always a RED FLAG - run away
Why can't jb weld fix it?
I agree with some other posters, check exhaust for an obstruction before a teardown. Never hurts to check it.
I remember when I could read jet #s without using glasses a flash light and magnifying tool.
😂😂😂😂😂
How old are you?....Just wanting to know when to expect it...😂
@@brainstain22 I'm almost 60... starts in your40s
I'm 42 this year....lol. Damnit....I'm getting old. 🤣
I’m 63 and need all those tools to read tyre sizes nowadays 😢😢
Love that year of CR. Great find.
Oh heck yeah I loved that bike same age as me
I thought it was rich but it wasn't but I also first thought PV at the first of the video, real fighter here. Been watching you're vid's forever and watched you turn into a top Tech!!!!!!
Man I buddy had one just like that and that thing was a handful but very fast
i have a 91 cr 250 and it seeps a little bit into the stator area , it runs like a champ , bike will pull wheelies on the power band alone in 5th , i weigh 160lbs .... cant wait for the full rebuild on this bike
Check the power valves
I’d be checking the plug wires and coil. Plug boot. I like how you are checking the jetting but I don’t do it the same way. Wide open for the main jet. Half throttle for the needle jet. Just get your rpm’s up a tiny bit and adjust the air screw when it sounds crisp. More than a 1/4 turn on the air screw each way move pilot jet up or down so your in the desired range of 1 1/4-1 3/4 or whatever the manufacturer says is stock.
I just bought a 03 cr250 with bad bog! It ended up being the power valves were adjusted wrong. the servo motor wasnt opening the ports for mine at the right time. If this ytear has that motor, definitely worth checking! It still has the slightest bog at low rpm so i will be doing a carb tuning like this in the near future. great video, hope you find the cause on this bike, these things EAT!
I'm going with the power valve. Seen it before on the Honda. Also had a similar issue with a Cat snowmobile. Pretty much similar symptoms. Both were dirty/sticking power valves.
Look at the baffle material in the silencer
Check for air leaks or obstructions in the exhaust. Ive had bith cause issues and make jetting next to impossible.
96 cr250 was my favorite bike of all time! Best engine no frame that year!
I once had a Yamaha 200 2 stroke 2 cylinder, as a boy of 14/15 year old, and at one point you had a mechanism on the ignition system with, when the engine made more rpm, the spark was made earlier by adjusting the moment that the points were opening. The ignition time was changing with more or less RPM.
Now did I buy a complete little set and I just put it on, and the engine did run but did not have the higher rpm anymore. Same as with your bike.
I also changed the carburetor, the exhaust pipes, and so on. He had more rpm when I made it leaner, but no power on the top....
I sold the thing before I found that.
Then I got a Yamaha YZ250 from I think from around 1985, and there I got the same problem when I got trouble with the engine.
The top of that Ignition changer was put on exactly the wrong way, so the ignition time didn't change but stayed the same all time.
Again bought it in original parts of Yamaha and I think the did the same thing again: assembled it exactly wrong.
I took the top of and turned it 180, so the time changed by more RPM and the problem was gone.
It is a bit silly explained, but I am dutch and not very well know with the technical terms in English.
I think it is about timing...
52 pilot on these hondas is what we ran.
Joe just did a complete restoration on my 93 CR 250 the kehin pj carbs sometimes just go bad idk what it is did it to me on my 90 CR 125 aswell. Seeing the you can’t get a genuine kehin airstriker right now anywhere the best option for not spending a ton of money on a lectron or smart carb is order a Q&A carb for your bike from Rocky Mountain with a jd jetting kit for a air striker run the needle and main jet from the kit with the needle on the 4th spot down and a 60 pilot jet which doesn’t come in the kit the bike will run perfect. Literally took me a week to figure this out seeing that it wasn’t a genuine airstriker carb talked to a few TH-camrs about this and the pointed me in the same direction hope this helps in total your looking at about 130 bucks for the kit and carb.
I had this same issue with a 91 cr125r and i couldnt ever figure it out to the point i just sold it.
That’s sad
@jayjudd6518 o well got a 01 kx250 with the money from it so 🤷 win win someone got the cr they wanted and I got the bike I wanted
Yea that sucks i had same problem yz125 2003 i changed all crank seals an i finally bought lectron carb an its fix it junk ass mukui carbs suck i love lectron carbs an apex head @@MrKawie1001
I have a suspicion the bog might have something to do with the JB Welded cracked engine case or a bad CDI Ignition or even a sheared off Woodruff key on the rotor/flywheel. Also check the ignition plug wire real good while running with the lights off and make sure it's not grounding out to the frame or engine. FYI I'm a 59 yr old FAA Certificated Airframe & Powerplant Mechanic since 1992 and have been repairing engines of many types from a young age approx. 7yrs old and I have 2 CR 500's for about 20yrs. 👍
Air filter is filthy
CRV valve....... always underestimated. clean & smooth as well as tight seat is key here. they screw with the air flow big time when the work sliw
Can't wait to see part 2.
Yeah check build-up in the expansion chamber....and look over the power valves. I'm thinking you'll find the answer in the power valves. Crank seals can def. effect tuning also though?
Power valve stuck shut
My favorite model Cr, awesome bike brother!! I wanna take time out as a real OG subscriber, and i want everyone to hit the like button for Joe his work ethic is unmatched