03 blaster ran great now it dont

[Joe Manteiga]

I have compression at 128 psi it has spark I just cleaned the carb it backfires it wont idle unless you feather the throttle and it dies after a couple of seconds I went riding last weekend it ran great I noticed the header was loose yesterday and ran crappy tightened header today and now wont run

 

[Larry's Shee]

I would suggest a new plug. If that doesn't help, leakdown test, carb clean, check flywheel key.

 

[Joe Manteiga]

I would suggest a new plug. If that doesn't help, leakdown test, carb clean, check flywheel key.

are there links for tutorial for the leak down test and flywheel key?

 

[speedyslyder]

i dont recall your other thread,but is your parking break on,or is there a wire coming out of your clutch lever/perch?

 

[Larry's Shee]

http://www.blasterforum.com/threads/leak-down-test-video.57629/

If Blaaster sees this maybe he'll post his linc/DIY . Just about every other post of his has it.

 

[Larry's Shee]

Check parking brake and tors if equiped. Pre 03 disco box under hood, 03+ find DIY on here. TORS does nothing but cause problems.

 

[Blaaster]

 

[mud runner]

my guess is if it is back firing it is the fly wheel key

 

[Blaaster]

my guess is if it is back firing it is the fly wheel key

Plus reeds and flooding.

 

[Joe Manteiga]

Plus reeds and flooding.

haven't had much time to work on the bike but the reeds aren't damaged I looked at them. and it holds 128psi consecutively. I thought a leak down was for when you can't hold compression?

 

[mud runner]

haven't had much time to work on the bike but the reeds aren't damaged I looked at them. and it holds 128psi consecutively. I thought a leak down was for when you can't hold compression?

you use A leak down when you rebuild your motor and then a problem comes up it is usualy the first thing to do

 

[Larry's Shee]

haven't had much time to work on the bike but the reeds aren't damaged I looked at them. and it holds 128psi consecutively. I thought a leak down was for when you can't hold compression?

You've confused leak-down with compression. Either/or could be good and other not. L/D tests seals and gaskets for ability to not let air IN. Basically engine is pressureized to 7psi and should hold for at least 7 minutes with very little loss. Never excede 7psi.

 

[Blaaster]

haven't had much time to work on the bike but the reeds aren't damaged I looked at them. and it holds 128psi consecutively. I thought a leak down was for when you can't hold compression?

It is all in a word.

A leak down test is the phrase for a test commonly performed on (wash my mouth out with caustic soda) 4 strokes.
It is used to diagnose wether lack of compression is due to leakage down past the rings or from the valves.

A leak test is performed on a 2 stroke to ascertain that the engine is leak free from the carby inlet to the exhaust outlet.

It tests the whole engine, gaskets and seals.

A leak test is very important as any air leaks in a 2 stroke can cause a catastrophic lean mix.

When folks on a site dedicated to 2 strokes use the terminology "leak down test" they really mean "leak test".