LCGB Forums

Earlier I changed my exhaust from a jl3 too a franspeed race, on start up I noticed quite a lot of smoke more than usual and it smelt different and it got worse after three miles or so, so my question is am I burning gearbox oil and if so which seal do I need to change.
thanks in advance.
phil.

Doesn't sound good. Get the engine ticking over and cover the end of the exhaust over so that you are effectively plugging it. If the engine splutters or stalls there is a good chance that the oil seal hasn't failed. If there is no significant change in the engine tick over then there is a good chance that the oil seal has failed.
If it has failed then it will be the drive side (kickstart side) oil seal and that will necessitate strip down of cylinder, mag housing, chaincase cover, front sprocket, crankshaft and all the other bits to get to it. Not to be undertaken if you are not confident. Having said that; it's the only way to learn.
Realistically doing it first time with good tools about 2 hours to strip and twice as long to rebuild.

how bad is the smoke ? the hand over the end isn't allways a reliable test on an exhaust with slip joints

quite bad enough to make me think I might have filled up with diesel, I will try blocking the tailpipe tomorrow and see what happens.

it could something left in the exhaust during manifacture , if the seals gone the smoke will be very thick and smell like something burning in the oven

The pipe is second hand but its funny it should do this from how it was with the old one.

my sons scooter got petrol in the wadding in the tail can which smoldered when the exhaust got hot causing it to smoke like billy o. once re packed problem solved

I did the tail pipe bloke test and thank god it cut out, so I'm going to check the timing just to make sure.

Try the other exhaust

I would take it on a good run first. Sticky uppy pipes tend to hold any oil and can smoke for a while till burnt off