Pit bike gearbox strip down. Taking apart a pitbike gearbox

Somebody asked me for a video of the gearbox coming apart so here it is !
don't forget to hit the like button if this video helps you out.

[@saynomoremedia5674]

Always well explained and love the videos 👌😉

[@motorcyclefixer]

Thank you very much 👍🏼

[@stephaniekane7276]

Great video , this will be super helpful when I rebuild my engine very soon

[@motorcyclefixer]

Thank you very much I'm glad you enjoyed it

[@gazking08mx]

You keep coming with great videos. Ths ks buddy

[@motorcyclefixer]

Thank you very much

[@E34turbo2.5]

Thanks you so much so helpfull video you tell everything And show slowly what goes where thanks❤️

[@motorcyclefixer]

I'm Glad it was helpful!

[@minibikeaction4266]

U have done a great video

[@motorcyclefixer]

Thank you

[@TheAdrianNightingale]

nice video, subscribed

[@motorcyclefixer]

Thank you 👍🏼

[@davidwillis5016]

Thanks again

[@motorcyclefixer]

No problem

[@connorjack3246]

Is the engine split in half for this or can you access them from taking just the clutch side casing off? Awesome videos man

[@motorcyclefixer]

Hi No you have to split the engine casings sorry

[@user-fs2gm2il4y]

I damaged my first gear on my Wpb 190cc my chain come off and jammed around the front sprocket so my first gear is no longer working but im clueless about changing it 🥴

[@motorcyclefixer]

It couldbe a number of things to be honest. You need to take it apart until you find the problem

[@nicholasmajor1113]

I have a yx 150 that cant find neutral. I have N bottom then 4 clicks up, and even after replacing the clutch hub gear that I found was initial culprit, when I was told motor was blown I'm still stumped, back tire still spins and clutch wont disengage gears or stop back tire from spinning.

[@motorcyclefixer]

If you turn the bike off and put it in neutral, try then to turn the back wheel. Is this turning the engine over or can it spin without moving the piston?

[@bmxscape]

i have some chinese 125cc pit bike... its started to make like a metal slapping sound when riding, in every gear , but it stops making the noise when the bike is in neutral or with the clutch pulled in. im assuming something in the gearbox is ratting around like a tooth broken off maybe? hopefully its something obvious like that.... it runs well and still shifts and rides fine just that noise of impending doom is forcing me to do something before its too late. ever had some mystery noises like that before only while in gear? as far as i can tell its not the primary chain but possibly could be the cam tension chain

[@motorcyclefixer]

It could be the timing chain tensioner i suppose What type of tensioner is on your engine It could be a few things i suppose. I would start to take it apart and see what you find

[@bmxscape]

@@motorcyclefixer i have pulled the motor out planning to take it fully apart and look for anything wrong, but since the first step is to remove the timing chain and head i guess i should check the tension and see if its sloppy. i know i had this head off before buti can't remember how the tensioner works. theres bolts on the bottom but theyre all screwed in fully so there is no 'locknut' kind of adjustment from what i see. but i have no idea what im looking at since im new to this stuff. sorry for being vague but im wondering if you have any generic advice for me? i guess to start i should figure out what kind of motor im working on(aka which motor china cloned it from, if any) and find some documentation

[@starry99los]

Does this also work if the engine has locked up ?

[@motorcyclefixer]

Hi Usually if the engine is locked up there's a problem with the piston, valves and cylinder good luck with it

[@MRMXMECHANIC]

Hi there mate i have a zongshen 190cc I have just recently just changed the selector drum as when I was riding it would be okay in 1st then as soon as I changed in to 2nd it sounded like the gears wer grinding so I stripped the engine down to find the gears were fine so I checked the selector drum and it seem to be abit worn on the forks so I ordered an new one long story short it doing the same thing in 2nd but jutted abit in e if the gears. You have any idea on what it could be mate your help would very much appreciated mate 👍🏼

[@motorcyclefixer]

Hi If it's just grinding in certain gears i would look to change the complete gear cluster if you cannot find anything else wrong with it

[@MRMXMECHANIC]

@@motorcyclefixer well today I’m going too pull my engine out Iv had a thought and think it be 2nd gear spinning on the shaft maybe we’ll see today but I think It could possibly be that and If can get away with buying second gear should be okay if not looks like a whole new gear box 👍🏼

[@motorcyclefixer]

@@MRMXMECHANIC good luck with it 👍🏼👍🏼👍🏼

[@YAMR1M]

If the gearbox is made the same as the Z155 then the dogs on the gearbox has a radius at the bottom of the dogs and it makes the gears try to push away from each other when you are riding. You need to get either a diamond file or very carefully use a multitool cutting disc and VERY carefully grind the radius to be a sharp 90 degree with no radius to stop it pushing into the gear selector forks and the selector drum. All the Z155 engines are like that so you either need to strip it from new to do it or run it for a few hours and once it is run in strip the engine and do it then. My engine has 13 hours total run time on it and the selector fork is wrecked and had to be replaced over the weekend.

[@tiitus4179]

Hey! i would have a problem with my 160yx engine when 2 gears raise to 3 gears, vaivde does not go on and does not work properly in 3 gears, 4 gears works without problems

[@motorcyclefixer]

Sorry I don't know what vaivde is but if you have a problem just with 3rd gear then you can change individual gears but you're better off changing the whole gear cluster

[@tiitus4179]

@@motorcyclefixer okay, i have new gearbox already... I think the gearbox is adjustment a not good

[@motorcyclefixer]

@@tiitus4179 make sure all the spacers are in the correct place One of my other videos show that Is the bolt in the end of the barrel behind the neutral switch

[@tiitus4179]

@@motorcyclefixer okay, thank you.

[@tiitus4179]

Hey! I have a problem with the transmission in my 150 Lifa. the gearbox rotates when the blocks have not been tightened and the gears change, but when the blocks are tightened the gears do not change or the entire gearbox does not rotate anymore. thank you in advance

[@motorcyclefixer]

Either one of the gears are damaged (or more than one) or one of the transmission assemblies are too long. You will have to dis-assemble the transmission and inspect each gear individually for cracks or bent teeth

[@tiitus4179]

@@motorcyclefixer okay. I buy new transmission and it start Works good

[@motorcyclefixer]

@@tiitus4179 excellent Well done 👍🏼

[@numberone3248]

Hi are stomp 140 engines reliable?

[@motorcyclefixer]

Change the oil regularly and make sure you pull the clutch in when you change gear and they are reliable 👍🏼