Squeaking Top End/pistons

[Magno]

Hello bikers,

My T140v has been juddering on acceleration for a while now so I adjusted the valve clearance which has helped but not solved the problem. Whilst doing this I became aware of a squeak from somewhere on the top end that occurs with each stroke of the pistons. It's quite loud and I'm afraid that it may signify that oil is not reaching something. I don't want to run the bike too long in case of damage. Could the jumpy acceleration and the squeak be related?
Any suggestions?
I rebuilt the top end 6 months ago and all was well until now.
Happy riding

Magno

 

[shanered6]

it could be air ascaping between the barrels and the head gasket , is it jumpy or is it missing ?

 

[Rocky]

it could be air ascaping between the barrels and the head gasket , is it jumpy or is it missing ?

I think you're onto something.
I've never had an engine seize, but it seems to me that lack of oil wouldn't result in squeaks before it quits.
As always, I could be wrong

 

[Magno]

it could be air ascaping between the barrels and the head gasket , is it jumpy or is it missing ?

Thanks Shanared and Rocky. I'll check the head gasket for leaks. I've read that if you hold a piece of tissue close to the join the escaping air should cause it to move.
The acceleration problem doesn't involve any backfiring but appears to be more due to the engine missing. As soon as it has reached higher revs it maintains a steady speed without further jumping. I wondered initially if it was a fuel supply problem. The carbs are only 6 months old and have run perfectly since fitting. However I noticed that the air screw is factory set to one and half turns out. I always used to use two and a half. Wonder if I should return to that?

 

[Magno]

PS. It is definitely jumpy on acceleration.

 

[Rocky]

I would try all external checks before opening up the engine.