Built 750sxi Issues

[Erik Jolliffe]

All, I have perused the posts and have tried bits and pieces of numerous tips to no avail. I thought I would detail the issues here and see what you all thought:

1995 750SXI
JRE Head 190psi
Coffman's pipe
Lightened stock flywheel

Stock dual 38 Keihin carbs
Main 125
Jet 75
Stock springs, needles, and seats

Issue is starting the ski is hit or miss. It turns over every time, however sometimes it's wide awake and ready to rip, and sometimes it is super boggy and borderline ready to die. If that happens I prime it twice, give it a little throttle and it wakes up ready to ride. No matter how it starts, once I get it going and stand up and ride, out of nowhere it will just big down and fall flat on its face. Sometimes it dies but sometimes it just stays boggy, I prime it twice, and it it's back to running good.

Here is what I have done so far to figure this out:

1) Cleaned the carbs, reinstalled, same thing.
2) Rebuilt the carbs with OEM parts, reinstalled, same thing.
3) Pulled motor, new seals, gaskets, fuel lines, fuel pickups, pressure tested to 8psi. Reinstalled, same thing.

I am about to go to a single Mikuni 44 carb and see what happens.

Any thoughts would be awesome.

EJ

 

[fastgtfairlane]

Check your tank vent. Sounds like you could be randomly loosing pressure in your fuel system.

 

[Erik Jolliffe]

Will do thanks

 

[fastgtfairlane]

It should let air through one way and not the other. If it let's air through in both directions it's bad. Should only let air into the tank not out