top end build issues

[racetim3]

Hello everyone, I just rebuild the top end, it was already 60 over and now it is a full mm over, I have fmf full exhaust and bought some new jets, the jet kit jumped from 240 to 340 so I have the 340 main in right now, I just finished the second heat cycle. When I kicked it over it started good and had kind of a high idle so I adjusted the idle screw and it was better then when it warmed up a little it was having a hard time staying running, I have the screw about 1.5 to 2 turns out and that seems to be the best spot for it but like I said it still seems to want to die and idle low before it does. Any help would be much appreciated.

 

[MURPH]

we need to know the temperature and elevation you ride in to help you more.. you can adjust the idle at the thumb throttle cable adjuster to raise it so it wont die

 

[racetim3]

Milwaukee wi, elevation about 600 ft. And it's around 10 degrees

 

[MURPH]

do you ride in the 10 degree weather or are you waiting for warmer weather? you should adjust your main jet every time the outdoor temperature changed 20 degrees or so ... what mods do you have? we need to know that too

 

[MURPH]

whoops sorry I missed the part where you said fmf exhaust ... with a stockish motor stock carb fmf I was running a 360 in 20 to 30 degree weather at sea level and it was a tad rich but better safe then sorry in the cold weather

 

[Blaaster]

The #340 main jet will not be causing any problem with the idle.

Did you set the float level to 20 - 21.5 mm

Have you leak tested the engine?

 

[racetim3]

Yeah well I'm about to hop on it and start the break in, I have two heat cycles down and that's the next step. Like I said it's bored 1mm over weisco piston dynojet 340 main stock pilot fmf fatty gold series with fmf power core 2 in the back

 

[racetim3]

The #340 main jet will not be causing any problem with the idle.

Did you set the float level to 20 - 21.5 mm

Have you leak tested the engine?

I have not adjusted the floats and have not done a Leak test, how do you leak test BTW

 

[Awk08]

how do you leak test BTW

http://www.blasterforum.com/threads/about-air-leaks-save-your-engine.55537/

http://www.blasterforum.com/threads/how-to-perform-a-leak-down-test.44653/

 

[harley1-5]

leak test is important for performance,and engine life

 

[tbrooks]

YES!! LEAKTEST!! Very important after any rebuild. Main jet only affects 3/4 throttle and up. Jet kits are usually crap, the sizes can't be trusted as much as single genuine mikuni jets. Jetting should not be an issue though until after heat cycles and 2 tanks of gas at below 3/4 throttle, Airleaks will however be a problem, and cause erratic and unexplained idle. Welcome also