125cc Engine Rebuild

9
Found 2nd Aug 2011
Have a 125cc scooter. Peugeot sum-up. Currently has an oil leak, and been told that the "engine bearings" have gone. And to fix would cost around £500. Assuming for the labour costs mostly.

Am playing with the idea of rebuilding the engine, replacing the broken parts ect.. as it is (from a quick google), a chinese engine so parts shouldn't be too hard / expensive to source.

Is there any guides on how to rebuild a 125cc / GY6 engine. Or can anyone offer any advice. At the moment, it's not going to be worth much at all. So it's either sell it cheap or try to fix it. I'm awaiting a quote from a bike company for a replacement engine / fitting.

  1. Misc
  2. Engine
Groups
  1. Misc
  2. Engine
9 Comments

Banned

Have you any mechanical experience
Taking the engine apart is fairly simple and the only thing you can get wrong when putting it back together again is the cam timing
You should have marks on the camshaft and flywheel so find and line them up before you take it apart so you know what it should look like when you put it back together
Use a gasket kit and while its apart replace the camchain tensioner as well

Original Poster

Tinkered with my car, general maintenance. I've got a haynes which covers the engine within the bike, so should be able to get a decent idea of what's what via that.

Awaiting a quote from a local garage to see how much it would cost to rebuild.

It would take me longer, but I think with the right amount of time should be alright. Hopefully.. I know someone who's been riding bikes and maintaining cars / bikes for a LONG time, so should be able to get some help from him. Possibly.

Banned

If you take your time its a days work if that, about it the only thing that might slow you down is taking the flywheel off and/or seized bolts

Thinking about it do you know exactly what they ment by engine bearings, if they ment the big end (it will be making a knocking noise) your probably looking at a new crank

Original Poster

It was noisy, so maybe that. I can check later to see exactly what they ment. How much is involved with removing it from the bike itself ? Is it just a case of undoing bolts etc.. Guessing you need to clamp the fuel cost and stuff like that.

How do you remove the flywheel. Attempted before, but was unable to do so. Do you need a specialist tool to do so ?

Original Poster

If the crank does need replacing, after a quick check a new crank for the bike is £120.

Is there any way to repair it ?

I suppose the only way to tell the full extent of the damage is to take it apart ? And see whats what.

Banned

Just a case of removing bolts/unplugging connections until the engine drops, if you haven't got a clamp you can usually get away with pushing a tight fitting bolt into the fuel pipe
don't forget to disconnect the battery first

If you haven't got or know anyone with a flywheel puller you should be able to hire one from local tool hire place, If not ask local bike garage if they will pull it for you, if you have a car to take the engine to them

Banned

smithmr8

If the crank does need replacing, after a quick check a new crank for the … If the crank does need replacing, after a quick check a new crank for the bike is £120. Is there any way to repair it ?I suppose the only way to tell the full extent of the damage is to take it apart ? And see whats what.



Cranks can be rebuilt but the labour/parts could take it over £120

Banned

You'll need to double check but i've read that this crank will fit yours
Ebay 160590319221

Original Poster

Ah right, cheers. Will have to have a think. Currently in a sellable condition, so might just cut the losses and sell it while I can.

Cheers for the help.
Post a comment
Avatar
@
    Text

    Top Discussions