jetting issues?

[cmblaster]

I put a brand new 240 kit and a brand new 3 mm stroker crank in. Fired right up but wouldnt stay running. So i jetted to the 340 jet and fired up and stayed running for a second then died. Now it wont fire and it kicks completely different. Still has massive compression though. It just dont feel the same. HELP PLEASE. Any ideas

 

[xKroniK13x]

Stock carb ?

 

[Awk08]

your main jet has zero to do with starting and idle.
check/set float height.
set airscrew for highest idle.
plug chops for the main.
and the jetting 101 thread.
the stickies on those can be found here.........

Engine - Carburetor at BlasterForum.com

 

[cmblaster]

Yeah stock carb. Gonna see bout get a different one tomorrow

 

[Larry's Shee]

Different what? Carb? Unless it's free, don't chase your tail , diagnos the problem first. Did you do a leakdown test on this build? What ratio are you using on your mix?

 

[Awk08]

Yeah stock carb. Gonna see bout get a different one tomorrow

thats not the solution, learning how to properly tune your carb is, read and learn the stickies i listed above

 

[cmblaster]

Ok i read the carb forum and kinda understand and will follow it to the T when i can get the motor running again. Now i cant get it to even start. If i kick hard its like it breaks free and just bouncez off the heel guard. If i only kick hard enough to push the kick start down it feels normal

 

[cmblaster]

I am mixing at 32/1. And i am not sure i know what a leak down test is. I dont know a whole lot about this and my mechanic up and took off. I cant afford to put it in the shop so i was trying to put it back together myself

 

[Awk08]

I am mixing at 32/1. And i am not sure i know what a leak down test is. I dont know a whole lot about this and my mechanic up and took off. I cant afford to put it in the shop so i was trying to put it back together myself

thats what we want to help you do, fix, repair and maintain it yourself.
again..read, re-read and try to learn the carb tuning stickies i led you too, then come back here and ask all the questions you want, and we we help you thru it.
but you have to read what we've already written/posted to try and get a handle on the simple functions and parts of this carb first.

leakdown test = pressurizing and testing your engine for any airleaks, which will suck air and create a lean condition, frying your piston.
it must be proven leak proof before any carb tuning can be done.

http://www.blasterforum.com/do-yours...wn-test-31464/

http://www.blasterforum.com/engine-1...-tester-33304/

http://www.blasterforum.com/miscellaneous-parts-154/slickerthanyou-leak-down-tester-47660/

 

[cmblaster]

What do i need to perform a leak down test

 

[Hillbilly_Proud]

A leak down tester. Contact slickerthanyou... he sells them at a good price. You can also search the forum for a diy on how to make one

 

[Larry's Shee]

Slickerthanyou makes testers. What I do is simular, plug intake, cap ex, use 4stroke tester from Harbor freight that screws into spark plug hole. Never excede over 7psi.

Slicks are about $20, can't hardly beat it.

 

[Hillbilly_Proud]

What I do is simular, plug intake, cap ex, use 4stroke tester from Harbor freight that screws into spark plug hole. Never excede over 7psi.

Slicks are about $20, can't hardly beat it.

Good idea Larry!

 

[Blaaster]

The problem with doing the leak test from the spark plug hole is that it does not test the seal between the reeds and the carby boot. The reeds confine the pressure to the crankcase.

The seal between the carby boot and reed block is notorious for leaking, especially if the bolts have been installed at the wrong tension or the correct tightening sequence has not been adopted.

An old carby boot is also prone to cracking and may be the cause of an air leak, a test performed at the plug hole will not detect a leak in this area.

Another concern is that if excess pressure is applied the reeds may suffer damage.