GY6 157FM engine timing chain keeps coming off By victor76 (Read 27,855 times)

[Alleyoop]

Yes, you will have to take the Variator off there is a bolt behind there that holes the TENSIONER GUIDE in place, the bottom guide just slides in and out.
Alleyoop

[victor76]

I'm sorry for being so new to this, the variator? could you link me to a picture which is a diagram of a engine like mine? or a video possibly that shows how to do this?

[royldoc]

No need to be sorry, we were all new to this at one time. Alley is very knowledgeable and will help you more than I can.

Roy

[Alleyoop]

I could not find any Videos I looked but no luck. But Look by the CRANKSHAFT on the Outside on the same side that the Chain is on. Right near the Crankshaft should be a bolt that should be the bolt that holds the Chain Tensioner.
If you cana take a picture of your motor of the left side I might be able to see it.
Alleyoop

[Alleyoop]

Ok Found a picture of my own motor to show you where about to look for yours.
Alleyoop

[victor76]

ok, i think i know what your talking about. but i have never accually opened that part of the engine, lol. shouldn't be too hard though looks like its just a few bolts, just to make sure ill upload a picture of my engine in the morning. Probably able to order parts tomorrow aswell. Also i just thought about it but the timing chain is kind of stuck behind that back sprocket, will there be a way to take it off the same route as getting that top guide off?

[Alleyoop]

BUMMER!! You might be able to free from the top with a long strong screwdriver or something and free it. Now when you get the new chain you will have to open one link on the old chain.
Then hook the new chain onto the OLD chain and pull the Old chain with the new chain threading the new one onto the crank sprocket. The only other method without taking the motor apart is to take the SEAL out by the crank behind the Variator and you will see the sprockets of the crank. And then fish the new chain onto the sprocket through there then get a log piece of wire make a hook on the end of it and grab the chain from the top. You will need a new oil seal on the crank. It is not easy but it can be done. You have some work to do and it is not going to be fun.
If you cannot do it then you will have to take the crank out to take the old chain off and put the new one on. For all that you will need new gaskets and seals.

So hopefully you can free it up from the top and thread the new chain through.
Alleyoop

[victor76]

Should it be fairly easy to take a link apart on the chain? if so then i should be able to thread it through there from the top of the engine, I didn't know if i was able to take a link apart though.

[victor76]

Also, if you can take apart a link on the chain and still put it back together, could you possibly explain how?

[Alleyoop]

Ok Victor found pictures of how to do it with the chain intact: I just finished putting it in the TIPS AND TRICKS you are going to love this:
Alleyoop
Go and look at how to do it:
www.scooterdoc.proboards.com/index.cgi?board=techs&action=display&thread=6112&page=1

[victor76]

I just thought of something i saw in a different post, could i have been putting the chain on wrong? as in the slack which needed to have tension on it was on the other side of the chain rather then the side with the tensioner on it? Would it be a good idea to put it back together with that in mind and see if it then works?

[victor76]

ok ill go and look now. Where do i find the tips and tricks?

[Alleyoop]

www.scooterdoc.proboards.com/index.cgi?board=techs&action=display&thread=6112&page=1

[victor76]

Ok, looks like a great way to do it, but in my previous post does it look like that could of been the case? or not likely?

[Alleyoop]

Well if you pull the chain up and hold it in the middle nice and tight that should go on one of the top teeth on the cam so the bottom and top should have the same slack. But maybe you had it tight on top and all the slack on the bottom COULD BE. I don't know how you put the chain on.
Alleyoop