Exhaust gasket? How to tell if the exhaust is blowing?

[pitbikeingmad]

Originally Posted by Jake1516

interested to know the answer about damage without one

There was no damage done, however i did end up lowsiding it and ripping the exhaust off...

[mysterious_rider]

There is a far easier way. Hold your hand over the exhaust can end. If the bike stalls out its sealed well. If it runs even when covered you have a leak.

To be fair though all of my pitbikes have had leaky exhausts. I think i bothered with a gasket for the exhaust only once.

[Despise]

a gasket should always be used anyway, as machined parts are never 100% flat

(why do you think you run gaskets between machined engine parts - bore, head, engine covers etc....)

If you can see the gap, then sure as hell it will be leaking. Like smify said, feel for it, put your hand in water if you have to, then you can feel the slightest bit of air rush and pin the throttle some

another option would be to use soap and water mix in a bottle and spray on, maake sure to use a lot of soap as the water will evaporate off immediately pretty much, with the soap, if theres an air leak you will see a gooy bubble

[yt#79]

You should be able to tell by the sound which sounds horrible to the normal 'tune' she plays

Originally Posted by Despise

a gasket should always be used anyway, as machined parts are never 100% flat

(why do you think you run gaskets between machined engine parts - bore, head, engine covers etc....)

I would have though that is more to do with the internal pressure and the fact that metal to metal wont create a tight seal, even if perfectly straight. A gasket fits in tightly between the 2 surfaces thus creating a perfect seal.

[Despise]

Originally Posted by yt#79

You should be able to tell by the sound which sounds horrible to the normal 'tune' she plays

very true, although I didnt mention this for a few reasons:

even if slightly lean may still run ok without exhaust glowing etc.... but with rasied temps. You would think popping would be a give away but with high lift cams and longer durations the overlap period is stretched making it pop anyway slightly especially on WOT to shut or vise verser with interuption stutter if too fast and low rpm.

2nd reason, most people wouldnt take any notice anyway and compensate with overly rich carb setting and jets making it run and act normal even with an exhaust leak

Originally Posted by yt#79

I would have though that is more to do with the internal pressure and the fact that metal to metal wont create a tight seal, even if perfectly straight. A gasket fits in tightly between the 2 surfaces thus creating a perfect seal.

excatly that too

although if the 2 surfaces were perfectly flat the heat from the exhaust would make the metals expand making a perfect seal anyway I would of thought in an ideal world

[mysterious_rider]

Originally Posted by Despise

very true, although I didnt mention this for a few reasons:

even if slightly lean may still run ok without exhaust glowing etc.... but with rasied temps. You would think popping would be a give away but with high lift cams and longer durations the overlap period is stretched making it pop anyway slightly especially on WOT to shut or vise verser with interuption stutter if too fast and low rpm.

2nd reason, most people wouldnt take any notice anyway and compensate with overly rich carb setting and jets making it run and act normal even with an exhaust leak


excatly that too

although if the 2 surfaces were perfectly flat the heat from the exhaust would make the metals expand making a perfect seal anyway I would of thought in an ideal world

Yes I think it was Aprilia that made their engine cases on one of their models gasketless as they were machined perfect so didn't leak oil. Pretty cool really.