cheap leak test

[Sticky]

So 5 mins with little/almost no pressure loss would be satisfactory?

Yes that's fine by the advice I've been given Jordan

[ROClarke]

So 5 mins with little/almost no pressure loss would be satisfactory?

Yes that's fine by the advice I've been given Jordan

Surely depends on what pressure you start with.
Nothing will hold for 5 mins at over 10 psi I would suggest.

[NorthernJordan]

I was going by the regularly quoted 5 psi

[kennystag]

Hi Grandpa,
What size of inner tube do you use for a 22mm carb and exhaust stubs.
Cheers
Stag

[Warkton Tornado No.1]

Hi Kenny.

I've always had cycles knocking about, & I use an inner tube that was intended for a mountain bike, though a kiddie's cycle tyre size will do. "Waste not want not" so an inner tube well-used or punctured is what I grabbed & have been using every since.

A 1.75 is common enough, though 2.25 would not be so much a stretch & you can always clamp with worm drive clips if needs be.

I use the valve (as intended for the tube) to inflate because you can soon tell if there is a leak & since I've been doing the test, the only leaks have been @ the spark plug area, which can be difficult to seal if you want to retain the captive washer. One cylinder head with a spark plug thread insert was also a challenge.

Good Luck!

Mark

[kennystag]

Thanks Mark,
Stag

[Pompeydave]

Hi all, I've just used the blood pressure valve and inner tube method for the first time- showed up a leak at the exhaust flange straightaway which is now gone after adding some sealant to the copper gasket. Does anyone know for sure what psi we should be testing at? No-one so far seems to know if the previously quoted 5psi is just a ball park figure, or is it based on knowledge from elsewhere?

***edit*** Just googled this and 5-6 psi held steady for five minutes is what almost everyone out there in cyberspace is recommending. Any more than 6 psi risks blowing the oil seals.

[Martin s]

This test showed leaking inlet manifold nuts, the obvious exhaust gasket, but most importantly for me, a leaky weld on a brand new exhaust u bend.