LCGB Forums

Hi all I'm having a mare trying to find a air leak have had a leak coming up throuh the studs and coming out of the nuts at the head that one sorted. Next leak coming out by the jacking holes on the mag housing mag housing sourced that leak fixed but when put under pressure there's a small leak which I can't find ive used more fairy liquid my hands are getting soft. I put it under pressure its starts to drop very slowly but when I warm it up with a heat gun it doesn't drop? So could I run with a small leak. Yes or no

Check your leakdown equipment,it may be leaking air.

I've checked the tube at both ends no leak

I use a foot pump and a bmx inner tube to do a leakdown test.At first there was an air leak and I couldn't find were it was leaking from.Eventually I found the leak,it was leaking from the pump itself,not the engine or the inner tube.I dont know what type of pump you use,but it may be worth checking it.

So could I run with a small leak. Yes or no

Its not ideal, however I've seen a few that drop the gauge needle very slowly and they've been fine, check your mag and drive seal, if you no sign of leaks from gasket faces?

How long does it take for pressure to drop. Built an engine some time back that did the same but couldnt locate any leaks. The engine ran fine all year.

Hi lads im using one of those hand held pumps with a dial im pumping it up to 140 it takes approximately 50 seconds to drop down to 135 it could be the dial? Im going to go back and try the inner tube and see if that works but it will be tomorrow night before I get to try it will let you know what happens