This was the most beautiful front end rebuild imaginable. When you started it up at the end that was the finishing touch that made it seem so simple. Of course this is not simple but you did a fabulous job of making it about as simple as it could get. I do not know of a video on any other type of motor, chainsaw, small engine or otherwise where the entire operation of rebuild was done in one video to completion. All the cuiting and editing was just great. Thanks for a great video,
I did that with my gy6 . Went from 50cc to a 80cc . Huge difference. Cvt tuning, jetting , exhaust made a huge difference. Can reach speeds up to 50. Which is nice for my backroads that require 40mph
After watching this tutorial I feel a lot more confident that I could do this myself. But my clumsy behind would probably end up breaking something anyway lol!
A bit of confidence and determination in yourself works. I've been scooting for over 10 years and this is the first scooter that I've been doing my own work on. It's pretty simple as long as you do what is shown in the videos on TH-cam 👍
You omitted changing the main jet or lifting the needle inside the throttle slide to allow more fuel through, also you should have oiled the cam and housing, other than that v.good tutorial.
Does the weight or mass of the new piston remain the same as the one from lower CC? I wonder about that since I would believe any changes in that would require a new Counterweight as well. Or, how does that work? maybe a new video addresing that for those who are curious about it?
I think when I swapped 139qmb heads, I installed the cam NOT @tdc. OR... the $40 donor 139qmb has different valve length as I hear tapping n clicking @ low speeds n idle. OR.. it's the lack of a proper head/exhaust gasket. I'll update in a couple days,.. BIG UP RWD!! from Kapolei, HI🤙🏾
Thank you for illustration a good how to video. I installed my big bore kit one shot no hiccups. Thank you. Please explain about installing a tachometer and correct reading for a big bore kit. Thanks again.
Im using this video to help repair my 150 i ran it without an air filter and a small rock entered the air intake and destroyed the top end... I have done a BBK kit on a 50 before and im confident i can fix my 150. Now i know to ALWAYS use an air filter 😎😎😎🤙
Are there two different gaskets or are they the same between the one that goes at the bottom if the jug and the one thst goes in-between the jug and the head i have a bunch of gaskets that were giving to me and i would like to know . For when i go to put a motor back together i want to do it the right way i have so many extra brand new gaskets
These are the numbers I found down by the kickstand kg1osa and underneath that is *2215982* on my kymco 50cc agility scooter, what motor do I have and will your "90cc" kit fit it??
I’m curious I’ve seen a few other videos and they said chrome piston ring up top but here you have black up top top does it differ from kits or is someone wrong
Thanks for video. I want to follow you to help install the monster 90cc big bore kit and camshaft in my 2021 linhai joc 49cc scooter. Will this kit work in this scooter? Thank you!
I run 150cc carbs on 50mm snm bigbore kits and i also ran into a problem trying to install one on a long case eton 4 stroke engine ill get the case number tmrw but ik its not qmb but it is a gy6 50cc engine but im now in the process of boring the case ill let you know what happens after i install the bigbore kit nd would the belt being squished nd used cause an engine to not pass 35 mph?
Do you guys do installations of big bore kits? I live in Denver and have a scooter, I'd like to install a kit in, but I don't trust myself enough to take it apart and install myself. Thanks!
Exhaust upgrade would be the next step, without it it’s still great. We are a mile above sea level here in Denver Colorado, the carburetor is fat out of the box. Once the big bore has been installed the jetting is perfect. So no rejet, however for most people yes.
What do you suggest the jets be increased to? I installed the 80cc bbk on my agility 50. Also installed pod filter and deleted air box. Having tough time getting over 30 mph. I’ve tried 90 and 92 on main jet.
@@colonelqb5 It’s different in different areas. Higher elevation vs. low elevation. Air is thinner up high, vice versus. So, each tune is & will always be slightly different a bit.
I need to be watching this because im doing a big bore kit here soon for my scoot i just not sure what carb setup im gonna use for it .. people are saying to just get bigger jets and some are saying to get a 21mm slide carb
But not sure what way I'm going to go just yet but I might get both and see what one is the better choice as far as performance goes . I'm still learning with these things too so I'm ok with buying both choices . For a trail and error type of thing can't hurt I don't think . Lol we will see in the near future . Wish me luck people in the scooter world . Take it easy every body positive vibes sending out
Great video man but I noticed that the piston is upside down. The arrow in the piston always shows the intake side. That's why it has larger gap for the valve move towards the piston.
Their is an arrow pointing down but in this case it must be the direction on flow therefore its pointing towards the exhaust and also next to the arrow it says in next to the top valve groove so it was deffinently in correctly
What is the success/fail rate of the stock QMB139 crankshafts with the 90 vs the 80cc BBK's? I think I'll go 80cc since I want the engine to last, I may go all the way and install a Naraku heavy duty crankshaft and upgrade oil pump.
I heard 80cc is as high as you can go before you need to change a whole bunch of other stuff. There is no oil pump (at least on mine). It’s described as “splash “. As the crankshaft turns, it splashed the eral over everything
From what i was told at a Bintelli dealer was the Naraku heavy duty crank and the 100cc BBC hold up as good as a 50cc when paired together. he said he has built alot of them.
Wait.. Did I hear you say the black ring goes on the top of the piston? Unless it's marked, I've always seen the silver ring on top and the black as the ring under it.
I have install the big bore kit on my 139QMB scooter. It runs great, but when my kid and I get on the scooter the pushes the rear main seal out and all of the oil leaks out. We are both total of 320 pounds. Does the back pressure increases because its too much weight for the motor to handle or do you think it’s some other issue when the big bore kit?
Nice but I installed a 150cc short case in my kymco agility only issues I have is stock rear rim don't fit replaced it with a 150cc rim with stock tire now tire rubs on inside left side of case and shock any info on fixing that .thank u
Short case GY6 150's can't accomodate a 12" wheel. The long case easily accomodates bigger wheels. The Agility can accomodate a long case GY6 150, just need a longer shock to prevent tire rub on the rear mud guard (or you can remove the mud guard and eliminate that problem).
I currently have a Kymco Agility 125. I did a GY6 swap at 40K, still going strong 10K later (just had to replace old parts along the way). Did you swap the stator from the old Kymco motor as well?
I bought an 8 dollar 6 inch LED light bar on ebay and spliced it in with the main headlight, then mounted it on the front and I went from barely seeing at night to seeing everything bro
@@MotoMiles for $13 on Amazon you can get the niilight 4 inch led lights there's 2 of them but now I'm running just one and the option of having a power switch is pretty darn satisfying
Great video, it was really helpful when doing mine big bore upgrade. However when I finished and tried to start the bike it didn't. I did manually turn the engine to ensure everything was ok. I don't know what I've done wrong.
When will you have this kit available again, It’s saying sold out. I would like the 90cc big bore kit & the crankshaft to for this unit the whole set-up. Also is this the 64mm or 69mm valves? I’d like 69mm please! Thanks P.s. I’m need a bigger carb to soon!!
So I have a Kymco Like 2 50i with injector and it is painfully slow it barely gets to 27 mph. I was thinking of installing big bore kit, however I am not sure if it would make any difference, due to the injector not supplying enough fuel? Also does the rpms of the engine need to be increased in order for that to work? Currently my max rpms are at 7000. I changed variator weights, opened the rear wheel gearing and it all seems as if its not restricted. However when I drive it the top speed is all the same. I had a bump in top speed to 33 mph when I installed new belt however that was just for 1 ride and then it fell back as previous. I am desperate in making it at least go 35. I am thinking the variator plate could be undersized as when I measured it, the diameter was about 70-80mm I don't exactly remember. I saw a video of a chinese ecu pushing the engine to 10k rpm, however it is incredibly overpriced. The gear ratio of the rear wheel is secondary 12/55 and primary 12/50 with 12 inch tires and the engine is I believe longcase. I am thinking of ordering malossi 2000 variator, because variator must be the only thing restricting that scooter. I would appreciate some input. I also considered reflashing the ECU to bump the rpms because there is no cdi box, however that would be very expensive and needs to be done by motorcycle ecu mapper
I have that same scooter but it is 150cc year 2021, it is compatible with all the gy6 parts? I want to put the new clutch and the 180cc kit..! Plz respond
Hi, you Comment that this fits the Agility from Kymco. Just for info: I have an 125 Agility from 2018 12 inch wheels and air cooled. Do tope end of the KN25SR engine on this scooter is compatible with GY6 or similar qmb139 Chinese generic engines? Do a Cilinder kit can be fitted? Thanks in advance
You have the special tool for valve adjustment. Feeler gauge is not needed. There is the scale, 1 turn divided by 12. The pitch of the screw is 0,5 mm. You turn the screw first to 0 clearance and then open as mush needed. 1/12 x 0,5 mm = 0,042 mm, 2/12 x 0,5 mm=0,083mm and 2,5/12x0,5mm=0,1mm. If you watch TH-cam Nicks Garage, he never use feeler gauge when adjusting valves in V8 motors. He opens the adjusting screw from 0 clearance half turn. Very easy method.
Ya you can use the stock one. But I will say on another note. There is no such thing as 90cc most eBay and Amazon listings call the 50mm a 100cc kit. They are actually 80cc. 52mm kits are 95cc
Followed your tutorial but I am hearing a quiet scrape or noise when turning crank by hand exhaust and intake are off spark plug is in. Is this normal? It turns over and only has resistance where it needs to
@RollingWrench thanks she runs fine so far. I have a question I put a 96 main jet in and have a pod filter on it how do I know if I'm running lean I get a pop on deacceleration but I drilled holes in the rear of stock exhaust to provide more flow it was popping before bbk is a 96 big enough
@RollingWrench question I took it out for a ride the second it hit 40 it started buzzing and beeping at me I thought it was my music at first but when I let off throttle it went away
I have a DF50SST and mine says qma139. Is it compatible? And what size carburetor would you recommend.? Even a jets size recommendation would be helpful. Thanks in advance
Will you please do a 50cc to 150cc swap on a Dong Fang 50cc SXR I have a pic if you can't find one by name I cant find anything on them and I wanna do a swap sooo bad
Thanks! Set the ring gaps for a Naraku 90cc big bore for my Maddog 50cc... It would have seized if I wouldn't have checked the gaps! Were at .004 needed .008" Just used a drill press vise to hold the ring square and my wife's nail file! Shh
You gaped the valves to .008? Did it work? I did my 100cc upgrade but having hard times to turn it on. It turns on if I jumpe started....could be my valves.? I have set them to .004
@@edwinjiscoa5695 I set the ring gaps to .008 not the valve lash. Valves set to .004 in and ex. 100cc made in Taiwan kit is a good upgrade along with a 24mm Taiwan carburetor.
Two questions. First I had to bore out my base to except the 83cc piston sleeve on my qmb -139. I noticed you said this was a qmb engine, did you have to do that with that kit? Second did you ever have to install a secondary pressure relief system? Now mine is upgraded with the exhaust carb and intake not stock. I ask because I had a oil seal blow out and the answer I found was this will happen with big bore kits on long runs and the stock system won’t handle the extra crank case pressure it makes.
I've done this kit on a kymco agility 50 when it had about 3000KM it worked great now I have 11000KM on it and I can barley get it started it's almost like it has to much compression cause when the piston makes a revelution it sticks if anyone has any pointers let me know
On the higher compression piston, barely push down tell you get passed the high compression. Then try kicking it started. Should start a lot easier. If, this is when using electric start only or mostly. Yes, I’d try adjustments on valves. Forsure
This was the most beautiful front end rebuild imaginable. When you started it up at the end that was the finishing touch that made it seem so simple. Of course this is not simple but you did a fabulous job of making it about as simple as it could get. I do not know of a video on any other type of motor, chainsaw, small engine or otherwise where the entire operation of rebuild was done in one video to completion. All the cuiting and editing was just great. Thanks for a great video,
I did that with my gy6 . Went from 50cc to a 80cc . Huge difference. Cvt tuning, jetting , exhaust made a huge difference. Can reach speeds up to 50. Which is nice for my backroads that require 40mph
did you end up switching out the carb or did you just change the jets? thanks.
@@betavirus11 just the jets
@@DomVito87 thanks for the reply.
@@betavirus11 no problem buddy! Good luck!
Wich Jet did you get?
Glad someone of your caliber is showing more chinese scooters.
After watching this tutorial I feel a lot more confident that I could do this myself. But my clumsy behind would probably end up breaking something anyway lol!
A bit of confidence and determination in yourself works. I've been scooting for over 10 years and this is the first scooter that I've been doing my own work on. It's pretty simple as long as you do what is shown in the videos on TH-cam 👍
Just remember to take your time and don't get in a hurry ☺️
Does this use 64mm or 69mm valves
Thanks just got 80 cylinder installed no issues
You omitted changing the main jet or lifting the needle inside the throttle slide to allow more fuel through, also you should have oiled the cam and housing, other than that v.good tutorial.
What size main jet should you use
Skipped over gapping the rings properly too if you follow this tutorial you'll probably blow your scooter up
Does the weight or mass of the new piston remain the same as the one from lower CC? I wonder about that since I would believe any changes in that would require a new Counterweight as well. Or, how does that work? maybe a new video addresing that for those who are curious about it?
Do you leave the EGR port open?
A secret I figured out pull the chain mark the very center of chain with sharpie then mark cam with sharpie perfect timing every time
but it can slip at the bottom.
I think when I swapped 139qmb heads, I installed the cam NOT @tdc. OR...
the $40 donor 139qmb has different valve length as I hear tapping n clicking @ low speeds n idle.
OR..
it's the lack of a proper head/exhaust gasket.
I'll update in a couple days,..
BIG UP RWD!! from Kapolei, HI🤙🏾
I'm going to have to watch that again once I have the parts
Thanks. Found it very usefull and it helped me to do my scooter faster and properly in 2 hours. Many thanks for this video.
Can you recomend the parts needed to upgrade the stator and other electrical components on a kymco agility 50 scooter?
This video was so helpful and if I had the tools I would do my own scooter with the 80cc Big Bore Kit... Thank you so much..
Thank you for illustration a good how to video. I installed my big bore kit one shot no hiccups. Thank you. Please explain about installing a tachometer and correct reading for a big bore kit. Thanks again.
Im using this video to help repair my 150 i ran it without an air filter and a small rock entered the air intake and destroyed the top end... I have done a BBK kit on a 50 before and im confident i can fix my 150. Now i know to ALWAYS use an air filter 😎😎😎🤙
I cannot stop wondering why people neglect obvious things
Are there two different gaskets or are they the same between the one that goes at the bottom if the jug and the one thst goes in-between the jug and the head i have a bunch of gaskets that were giving to me and i would like to know . For when i go to put a motor back together i want to do it the right way i have so many extra brand new gaskets
Great tutorial video matt ...🙂👍I'm currently working on my 50cc thinking about upgrading her to a 80cc
Thanks dude! Do itttt!
I've been looking at upgrading my 50cc been looking at a big bore kit for it
After every thing done and finish what kind of horsepower is it putting out
3 from stock and maybe 5 with this? Don't know
Will putting a 100cc big bore kit on a 50cc , cause any long term damage to the crankshaft? And should I put on a higher volume oil pump as well?
yes you will need to upgrade ur crankshaft
This is why most scooter techs recommend for daily commuter scoots to stay 80cc if you are going to stay stock crank wise.
How does this big bore kit compare to the 100cc kit from J&J Power Sports?
I'm ordering this kit with the new cam my kymco 50 agility I'm excited to do this I never done one before so learning on the fly lol
It’s rewarding and not to difficult.
I see you sell a video on a step by step on how to do it, I think that will be a good investment too
These are the numbers I found down by the kickstand kg1osa and underneath that is *2215982* on my kymco 50cc agility scooter, what motor do I have and will your "90cc" kit fit it??
What tools do I need to change the crank shaft
What size carbs and jets are you guys going with with these 100 cc swaps?
nice video! did a 90 cc measly kit on my gy6 retro grande ;-) but what mm carb do you recommend? it is a 18.5mm right now
You should have a follow through on the engine break in after bbk.
I’m curious I’ve seen a few other videos and they said chrome piston ring up top but here you have black up top top does it differ from kits or is someone wrong
Are there still advantages with this on stock 50cc my son races 4 wheelers and can not bore thank you
Thanks for video. I want to follow you to help install the monster 90cc big bore kit and camshaft in my 2021 linhai joc 49cc scooter. Will this kit work in this scooter? Thank you!
I run 150cc carbs on 50mm snm bigbore kits and i also ran into a problem trying to install one on a long case eton 4 stroke engine ill get the case number tmrw but ik its not qmb but it is a gy6 50cc engine but im now in the process of boring the case ill let you know what happens after i install the bigbore kit nd would the belt being squished nd used cause an engine to not pass 35 mph?
Do you guys do installations of big bore kits? I live in Denver and have a scooter, I'd like to install a kit in, but I don't trust myself enough to take it apart and install myself. Thanks!
With all these mods, isn't the exhaust now restrictive? Did you rejet carb?
Exhaust upgrade would be the next step, without it it’s still great. We are a mile above sea level here in Denver Colorado, the carburetor is fat out of the box. Once the big bore has been installed the jetting is perfect. So no rejet, however for most people yes.
What do you suggest the jets be increased to? I installed the 80cc bbk on my agility 50. Also installed pod filter and deleted air box. Having tough time getting over 30 mph. I’ve tried 90 and 92 on main jet.
@@colonelqb5 It’s different in different areas. Higher elevation vs. low elevation. Air is thinner up high, vice versus. So, each tune is & will always be slightly different a bit.
I need to be watching this because im doing a big bore kit here soon for my scoot i just not sure what carb setup im gonna use for it .. people are saying to just get bigger jets and some are saying to get a 21mm slide carb
But not sure what way I'm going to go just yet but I might get both and see what one is the better choice as far as performance goes . I'm still learning with these things too so I'm ok with buying both choices . For a trail and error type of thing can't hurt I don't think . Lol we will see in the near future . Wish me luck people in the scooter world . Take it easy every body positive vibes sending out
Great video man but I noticed that the piston is upside down. The arrow in the piston always shows the intake side. That's why it has larger gap for the valve move towards the piston.
If it was backwards we would have big issues. The valve would hit the pistons
Their is an arrow pointing down but in this case it must be the direction on flow therefore its pointing towards the exhaust and also next to the arrow it says in next to the top valve groove so it was deffinently in correctly
Talk about taxing on the price, HOLY SHIT!! $300 for 120cc jesus christ this is why i LOVE EBAY
What size piston and valves are with this kit? I cant find the details anywhere...
What is the success/fail rate of the stock QMB139 crankshafts with the 90 vs the 80cc BBK's? I think I'll go 80cc since I want the engine to last, I may go all the way and install a Naraku heavy duty crankshaft and upgrade oil pump.
I heard 80cc is as high as you can go before you need to change a whole bunch of other stuff. There is no oil pump (at least on mine). It’s described as “splash “. As the crankshaft turns, it splashed the eral over everything
From what i was told at a Bintelli dealer was the Naraku heavy duty crank and the 100cc BBC hold up as good as a 50cc when paired together. he said he has built alot of them.
Wait.. Did I hear you say the black ring goes on the top of the piston? Unless it's marked, I've always seen the silver ring on top and the black as the ring under it.
Hey watch this guy he goes really in depth with putting the rings on
th-cam.com/video/0-GPXbM7qRU/w-d-xo.html
Just what is that valve adjustment tool called? Not seen one before.
How many miles can you do with this 90cc bigbore kit ?
No chance to crack the engine base or the crank itself ?
im doing an 80 cc one right now to try and prevent that
I'd recommend not exceeding 80cc for longterm reliability, unless you do a crank swap to a better crank like a naraku, etc...
What is the hose he removes at exactly 6:52?
Does this fit on a peugeot kisbee 50cc 139gmb-e 4T carb?
Is that fit peugeot kisbee 50cc 139 qmb-e
What did you use to scrape the old gasket off?
I would use a razor blade to get it off if it's not really stuck on . Just be careful
The 2 nuts to remove the head stud is the smartest thing I’ve seen this week.
I have install the big bore kit on my 139QMB scooter. It runs great, but when my kid and I get on the scooter the pushes the rear main seal out and all of the oil leaks out. We are both total of 320 pounds. Does the back pressure increases because its too much weight for the motor to handle or do you think it’s some other issue when the big bore kit?
Does it do it when you ride single? if not... you have your answer
Nice but I installed a 150cc short case in my kymco agility only issues I have is stock rear rim don't fit replaced it with a 150cc rim with stock tire now tire rubs on inside left side of case and shock any info on fixing that .thank u
12 " agality or what model ? I was a kymco dealer in Vegas for 15 years
Chris i have a 2015 agility 50 4t
Short case GY6 150's can't accomodate a 12" wheel. The long case easily accomodates bigger wheels. The Agility can accomodate a long case GY6 150, just need a longer shock to prevent tire rub on the rear mud guard (or you can remove the mud guard and eliminate that problem).
I currently have a Kymco Agility 125. I did a GY6 swap at 40K, still going strong 10K later (just had to replace old parts along the way). Did you swap the stator from the old Kymco motor as well?
MetroLinerXLZ awsome
Do these pistons not use needle bearings? Is that cus its a 4 stroke if so?
can I use the stock rocker arms assembly on 100cc big bore kit or do I have to get a new one ?
We need a video on a better headlight for scooters
Led
I bought an 8 dollar 6 inch LED light bar on ebay and spliced it in with the main headlight, then mounted it on the front and I went from barely seeing at night to seeing everything bro
@@anonymoose6873 hmmm i am thinking about doing something similar..
@@MotoMiles for $13 on Amazon you can get the niilight 4 inch led lights there's 2 of them but now I'm running just one and the option of having a power switch is pretty darn satisfying
@@anonymoose6873 awesome thank you brother !!!!
Great video, it was really helpful when doing mine big bore upgrade. However when I finished and tried to start the bike it didn't. I did manually turn the engine to ensure everything was ok. I don't know what I've done wrong.
Did you got it to work?
Did you fix it?
Did your problem end up having to change your carburetor jets?
@shabirfazal
Did you adjust the valves
Hi there ! It's possible to cut the case of my gy6 150cc short case ? For a bobber proyect with 16 inch wheels ??...Have a great day amigo!!
Can I put a 50mm head on a stock cylinder? Or do I have to get a new cylinder too? My bike is a Tao Tao atm 50
with the big bore kit fron 50 to 100cc no need refit the carburator??
Is it ok to use the stock cam
both of the exhaust valves were at .004? I thought top one was .003 and bottom was .004. does that matter? should I change mine?
.001 variance should not make that much of a difference. At best, you’ll get some tapping noise
Some qmb139 will require case boring... some 80cc -100cc big bore kits have the thicker cylinder walls that wont fit into the 50cc cases
True, but all of our cylinder kits drop in
So the exhaust valve is a 4 too?
Yes 0.004
@@RollingWrench This explains so much. I had mine set for my old 50cc gy6. Thank you!!
When will you have this kit available again, It’s saying sold out. I would like the 90cc big bore kit & the crankshaft to for this unit the whole set-up. Also is this the 64mm or 69mm valves? I’d like 69mm please! Thanks
P.s. I’m need a bigger carb to soon!!
What happens if you get the two rings switched the one video the black was in the middle and this one is black on top do i need to tear apart
I'm in the middle of doing this , if some know if it's no big deal and i can continue without worrying
What’s that special tool called?
So I have a Kymco Like 2 50i with injector and it is painfully slow it barely gets to 27 mph. I was thinking of installing big bore kit, however I am not sure if it would make any difference, due to the injector not supplying enough fuel? Also does the rpms of the engine need to be increased in order for that to work? Currently my max rpms are at 7000. I changed variator weights, opened the rear wheel gearing and it all seems as if its not restricted. However when I drive it the top speed is all the same. I had a bump in top speed to 33 mph when I installed new belt however that was just for 1 ride and then it fell back as previous. I am desperate in making it at least go 35. I am thinking the variator plate could be undersized as when I measured it, the diameter was about 70-80mm I don't exactly remember. I saw a video of a chinese ecu pushing the engine to 10k rpm, however it is incredibly overpriced. The gear ratio of the rear wheel is secondary 12/55 and primary 12/50 with 12 inch tires and the engine is I believe longcase. I am thinking of ordering malossi 2000 variator, because variator must be the only thing restricting that scooter. I would appreciate some input. I also considered reflashing the ECU to bump the rpms because there is no cdi box, however that would be very expensive and needs to be done by motorcycle ecu mapper
I have that same scooter but it is 150cc year 2021, it is compatible with all the gy6 parts? I want to put the new clutch and the 180cc kit..! Plz respond
Kymco súper 8 150cc 2021
Parts I want to buy
-Reveno clutch
-180cc kit And head
-gy6 variator
Is it compactable?
Is this kit available for a 2022 vitacci Denali 50?
Hi, you Comment that this fits the Agility from Kymco. Just for info: I have an 125 Agility from 2018 12 inch wheels and air cooled. Do tope end of the KN25SR engine on this scooter is compatible with GY6 or similar qmb139 Chinese generic engines? Do a Cilinder kit can be fitted? Thanks in advance
You have the special tool for valve adjustment. Feeler gauge is not needed. There is the scale, 1 turn divided by 12. The pitch of the screw is 0,5 mm. You turn the screw first to 0 clearance and then open as mush needed. 1/12 x 0,5 mm = 0,042 mm, 2/12 x 0,5 mm=0,083mm and 2,5/12x0,5mm=0,1mm. If you watch TH-cam Nicks Garage, he never use feeler gauge when adjusting valves in V8 motors. He opens the adjusting screw from 0 clearance half turn. Very easy method.
Does intake on piston go on top
Hey I got a question I got just the 100c piston, but I didn’t get a new head can I still use the stock one ??
The part your putting back on 23:42
I didn’t get one those you think I can use the stock one I got
Ya you can use the stock one. But I will say on another note. There is no such thing as 90cc most eBay and Amazon listings call the 50mm a 100cc kit. They are actually 80cc. 52mm kits are 95cc
How many mm is the piston on this kit
Followed your tutorial but I am hearing a quiet scrape or noise when turning crank by hand exhaust and intake are off spark plug is in. Is this normal? It turns over and only has resistance where it needs to
Be sure the spark plug is out when you turn it over. If it still scraps pull it back apart to see what the issue is
@RollingWrench thanks she runs fine so far. I have a question I put a 96 main jet in and have a pod filter on it how do I know if I'm running lean I get a pop on deacceleration but I drilled holes in the rear of stock exhaust to provide more flow it was popping before bbk is a 96 big enough
@@gameribanez9796 to know for sure get a wide band:
www.rollingwrenchdenver.com/products/wide-band-o2-sensor-tuning-kit?_pos=1&_sid=24c770cfa&_ss=r
@RollingWrench question I took it out for a ride the second it hit 40 it started buzzing and beeping at me I thought it was my music at first but when I let off throttle it went away
@RollingWrench is there some sort of warning horn?
do i need to drain the oil from it before working on it ? (asking because i do not have the tool for the bolt to drain it)
No. You can do a big bore kit without draining the oil
Can I do this to my kymco people 50 2T or is there a specific kit for me??
Whats the actual size of the piston
47mm for 71cc, which they call "80cc", and 50mm for 80cc, which they call "90cc".
Nice and good work Super job 50 cc beter economische now en relaxing
I have a DF50SST and mine says qma139. Is it compatible? And what size carburetor would you recommend.? Even a jets size recommendation would be helpful. Thanks in advance
Yes, it will work. I use this carburetor, jetting is always different :www.rollingwrenchdenver.com/products/gy6-125cc-150cc-carburetor
Do you need to drain the oil when doing a big bore kit
No :-)
I would. When take everything apart, the crankcase will be exposed. If you drop a bolt in there, it’s going in the oil.
Does my Kymco super 8 4t
50cc (2018) have the same engine as the agility ?
Yes
Home does it effect gas mileage. .?
I have a Kymco Agility 50, do you need to bore the case for the cylinder jug to fit properly when you go this big?
This kit is a drop in kit. No boring needed
do i need to change my crankshaft and rod to put a big bore on my gilera runner 50cc?
will this fit on a honda squash engine?
can you swap a larger engine into one of these scooter frames will they fit?
They mount different . Short answer is no :-(
I have a 2018 SYM symply 50 I don't think this kit of compatible but does anyone know what kits / upgrades I can do to my bike o can't find any myself
Will you please do a 50cc to 150cc swap on a Dong Fang 50cc SXR I have a pic if you can't find one by name I cant find anything on them and I wanna do a swap sooo bad
Thanks! Set the ring gaps for a Naraku 90cc big bore for my Maddog 50cc... It would have seized if I wouldn't have checked the gaps! Were at .004 needed .008" Just used a drill press vise to hold the ring square and my wife's nail file! Shh
You gaped the valves to .008?
Did it work?
I did my 100cc upgrade but having hard times to turn it on.
It turns on if I jumpe started....could be my valves.? I have set them to .004
@@edwinjiscoa5695 I set the ring gaps to .008 not the valve lash. Valves set to .004 in and ex. 100cc made in Taiwan kit is a good upgrade along with a 24mm Taiwan carburetor.
Also installed a high torque starter and ran 6 gauge wire from the battery to the starter both gnd and positive cables. She cranks over now!
@@fanofoldfans9238 thank you....gonna try and see
@@fanofoldfans9238 my stator is 8 poles 5 wires, the 6 gage wire that you used, to which cable from the 5 wire is connected to?
Will this jeopardize the reliability of my Kymco? I’ve had mine for 2 years now & it starts every time. It’s never given me any issues.
Any time you increase the performance you decrease the reliability.
Just bought and was installing the kit and realized I have lost the Circlips, anyone know the size and dimensions of these Circlips?
its hard trying to line up that timing. I ran out of daylight
Two questions. First I had to bore out my base to except the 83cc piston sleeve on my qmb -139. I noticed you said this was a qmb engine, did you have to do that with that kit? Second did you ever have to install a secondary pressure relief system? Now mine is upgraded with the exhaust carb and intake not stock. I ask because I had a oil seal blow out and the answer I found was this will happen with big bore kits on long runs and the stock system won’t handle the extra crank case pressure it makes.
I did not have to bore the case on this kymco Agility. I do sell a dipstick breather to relieve the pressure, however I have not heard of these issues
how fast can you go with this kit?
I've done this kit on a kymco agility 50 when it had about 3000KM it worked great now I have 11000KM on it and I can barley get it started it's almost like it has to much compression cause when the piston makes a revelution it sticks if anyone has any pointers let me know
Check valve,s and change oil every 5000 km also check timing belt
On the higher compression piston, barely push down tell you get passed the high compression. Then try kicking it started. Should start a lot easier. If, this is when using electric start only or mostly. Yes, I’d try adjustments on valves. Forsure
hi, peugeot kisbee 2018 50cc enjection 139qmbj engine code. Is it compatible?
Great vid. Very informative. Keep up the great work.
What jetting for 50mm bbkc??
It’s never the same
@@RollingWrench assuming 85 to 95 in that range for jetting
Awesome video, question did you keep the factory carb and intake?
I have a question I ordered a big bore kit 80cc for my 49cc would I have to change my carburetor or is the stock one fine? Thanks
Stock is fine. Just raise your main jet up a few sizes to account for more fuel in the motor.
@@JHayes90 hey Cat man what is the rocker arm that he use what's the millimeter for the 90cc I freaking need help.? I keep getting a damn wrong ones
Can you adapt a stator for gy6 150 into a 50cc to power fuel injection
No, it won’t fit
Hello I was wondering I'm planning on doing a 100cc kit upgrade do you sell those
100cc doesn’t exist. Only eBay and Amazon sell those. They lie. They call an 80cc a 100cc and it’s only 50mm. We have 95cc 52mm kits on our site
Please send me a link sir
@@RollingWrench do you have a link to the kit
@@kevinrohde7948 www.rollingwrenchdenver.com/products/90cc-monster-big-bore-cylinder-kit?ToPasteboard
@@RollingWrench is it a drop in kit or does it need to be bored out
those 3 tiny pistons are cute
Will this fit the 1p39qmb?
Same engine. The P just means horizontal engine. Some manufacturers put that on there, some don't
I've had a few people tell me that the arrow goes up so I put it in the wrong?
Everything in my video is correct. This bike is still on the road