High Revving - air leak - failed gasket
Posted: Mon Apr 30, 2018 9:11 pm
Hi All,
As some of you may know I have a li150 which was bought last year. I haven't been out on it much so far - mainly due to poor weather and sorting bits on it (maybe a blessing in disguise if you read on). Its latest issue is a high revving engine on start up. i.e start it and it sounds like its going to take off. So much so I can only run it for a few seconds before switch off.
Anyway, I have been running tests and my novice prognosis came down to an air leak. I have checked the carb with the WD40 test and cant find anything there (in fact I have stripped it twice). However, I moved onto the leaking exhaust (which is now off the scooter). I have included a couple of pics here from my Flickr album - there are a lot of pics so just thought I'd include a couple to begin with). It looking very likely to be the exhaust gasket thats done the damage. BTW, there was no exhaust clamp between U bend and main body of the exhaust and the joint between the two was leaking. All in all a bit of a mess!
https://www.flickr.com/photos/153041800 ... ed-public/
https://www.flickr.com/photos/153041800 ... ed-public/
As you can see I have now got a very scored piston - looks like carbon from the air leak??
Going forward I definitely need to replace the gasket as a starting point- but do I need to replace the piston as its too far gone? The exhaust has a fair bit of wear and tear as well.
As ever grateful for any advice on this issue.
As some of you may know I have a li150 which was bought last year. I haven't been out on it much so far - mainly due to poor weather and sorting bits on it (maybe a blessing in disguise if you read on). Its latest issue is a high revving engine on start up. i.e start it and it sounds like its going to take off. So much so I can only run it for a few seconds before switch off.
Anyway, I have been running tests and my novice prognosis came down to an air leak. I have checked the carb with the WD40 test and cant find anything there (in fact I have stripped it twice). However, I moved onto the leaking exhaust (which is now off the scooter). I have included a couple of pics here from my Flickr album - there are a lot of pics so just thought I'd include a couple to begin with). It looking very likely to be the exhaust gasket thats done the damage. BTW, there was no exhaust clamp between U bend and main body of the exhaust and the joint between the two was leaking. All in all a bit of a mess!
https://www.flickr.com/photos/153041800 ... ed-public/
https://www.flickr.com/photos/153041800 ... ed-public/
As you can see I have now got a very scored piston - looks like carbon from the air leak??
Going forward I definitely need to replace the gasket as a starting point- but do I need to replace the piston as its too far gone? The exhaust has a fair bit of wear and tear as well.
As ever grateful for any advice on this issue.