sticky oil in cylinder/head

[lam1962brettagg]

li150 s3 having seizures/noise. Recently taken head and cylinder off to find very sticky oil deposit in cylinder head especially. never known this with two stroke oil before is this normal with semi-synthetic. Just changed from the old red cheap nasty 2-stroke oil which I have always used for years to Castrol 2T for scooters.

[St George]

Too much 2 stroke oil ? Is it firing ok, try premium petrol and a new plug; could be a weak spark.

[lam1962brettagg]

Thanks for reply St George.
4% as ive always used.
spark seems strong.
Runs fine but starts making a noise after 3to4 miles as if it's going to sieze. I've just taken head and piston out and does have scores on piston. Very fine hairline scratches on piston as well.
Just still want to know whether semi-synthetic oil can be sticky in the head /small end bearing etc. I'm concerned it's coming from gearbox

[dscscotty]

We've been having similar symptoms in the Teesside area with several, high mileage, generally reliable motors seizing. scuffing or holing of pistons,the four motors I have looked at all had similar oily coating which had become quite sticky, quite similar to gear box oil. None of the engines had drive seal failures, all ran different two stroke/ratio's etc. We fear that the issue is being caused by high ethanol/additive content in fuel and some sort of reaction/separation. Its not just affecting Lambretta's there's been issues with standard px125/P200's and auto's.

[Scooterdude]

li150 s3 having seizures/noise. Recently taken head and cylinder off to find very sticky oil deposit in cylinder head especially. never known this with two stroke oil before is this normal with semi-synthetic. Just changed from the old red cheap nasty 2-stroke oil which I have always used for years to Castrol 2T for scooters.

Can you not switch back to your old oil once you put it all back together and see how it goes for a while?

[lam1962brettagg]

thanks to all for your posts and info. especially scotty re similar probs.
will change my fuel/garage and oil see if that makes a difference.
after the engines rebuilt yet again!!

[dscscotty]

I've sent you a PM,

Regards-Scotty-DSC

[daniel whiteley]

Try some of this aswell

https://www.dipetane.com/

[lam1962brettagg]

thanks for the link. will look into it.
cheers