Air leak ( I think)
-
bryansmudge
- registered user
- Posts: 45
- Joined: Mon May 17, 2010 2:21 pm
- Contact:
On the way back from MOT, scooter wouldnt return to idle as quickly as normal. The revs weren't running away, just sort of slowly pulsing if you get what I mean. Got her home, and checked her out found that the base gasket had been pushed out from underneath the cylinder and a fair bit of oil too. I know a air leak will give these symptoms, just a tad surprised that the base gasket would do the same, coz it's the other side if the piston. I'm gonna change this and the head gasket, what else should I be lookin for? It's a bog standard TS1, thanks in advance.
-
olliewtf
- registered user
- Posts: 229
- Joined: Thu Feb 06, 2014 1:08 pm
- Main scooter: Lambretta Li S3
- Contact:
make sure you replace the base with the same thickness gasket you took off, although im sure you would have done anyway.
last time i built my top end my base gasket blew in less than 200 miles, and i put it down to the silicon sealant i was using, which had made the gasket brittle, also none of it was actually stuck to the barrel or case, so it clearly wasnt doing its job. I just used grease when i rebuilt it.
have you had your cases ported? might be worth also checking for any hairline cracks or to see if the edge of the casing on the transfers have been overdone and are essentially acting like a knife, cutting your gaskets as your torque it down.
last time i built my top end my base gasket blew in less than 200 miles, and i put it down to the silicon sealant i was using, which had made the gasket brittle, also none of it was actually stuck to the barrel or case, so it clearly wasnt doing its job. I just used grease when i rebuilt it.
have you had your cases ported? might be worth also checking for any hairline cracks or to see if the edge of the casing on the transfers have been overdone and are essentially acting like a knife, cutting your gaskets as your torque it down.
How tight was your mag flange ive welded alot of cases on that side were magflanged have been hammered in ...
We sleep soundly in our beds because rough men stand ready in the night to visit violence on those who would do us harm
Its worth checking you have a 200 flange as well or at least a 125/150 ported to suit and check the spigot in that area isnt touching the mag flange transfere cut out
We sleep soundly in our beds because rough men stand ready in the night to visit violence on those who would do us harm
-
bryansmudge
- registered user
- Posts: 45
- Joined: Mon May 17, 2010 2:21 pm
- Contact:
Cheers fellas, mag flange will be checked out too. The engines been sound for around 6 k miles, haven't touched her since I built it. I've ordered some packers of various thickness so will play about and get the transfers right. I'll try and make up the pressure test kit before I put a light in her first though. Cheers
-
bryansmudge
- registered user
- Posts: 45
- Joined: Mon May 17, 2010 2:21 pm
- Contact:
Problem found, one of the exhaust nuts had worked loose. Ahem! All after removing the engine from the frame, setting up a leak test kit...did the leak test anyway. Everything sorted only leak was the exhaust stub.