leak down question

[badshee1998]

What do you consider a passing leak down test? started with 6lbs and after 6 minutes it was down to 4lbs.. whatcha think?

[Phelps]

pass

 

hell i will run it even if it takes all 6 minutes to lose the 6lbs. just know you have to jet for it. it's the leaks that happen after jetting that kill engines

[J.J.]

Sounds ok, some dish washing liquid/water solution brushed onto the seals and case mating surface could show where the leaks are in the form of bubbles. Worth a quick check before you pack away all the equipment.

[badshee1998]

Thanks guys, soapy water helped me detect the leak between the reeds and motor. got er all sealed up!

[BansheeBanditBrian]

Do you have to have your motor at operating temperature to perform a leak down test ? How about the compression test does the motor have to be at operating temperature?

[Jereme6655]

Do you have to have your motor at operating temperature to perform a leak down test ? How about the compression test does the motor have to be at operating temperature?

 

For compression tests your going to gt different responses for whether it needs to be warmed up or not....

 

For a leak down test....unless your work fast as lightning and use oven gloves....it ain't gonna be warm when you actually test it as you have to remove the exhaust and the carbs....

[dirtydownunder]

compression must be checked when hot, for accurate results.

 

leak down doesnt.

[BansheeBanditBrian]

Great, thanks guys.

[FASTOYS]

They say 1 lb per min. is acceptable loss. But if it's a motor we build it wont leave the shop until there are NO leaks!! Glad you found the leaks. : )