Beyond Frustrated with my Mikuni Carb - May go to Tillotson

[budzinsk]

Hi Everyone. I wanted to see if anyone has used a Tillotson carb on a JLO 400 in and Attex? My JLO has a Mikuni carb on it - as per the factory and it leaks (not sure from where). I replaced the intake, and got another carb and still the same thing. Replaced the fuel pump twice and all of the lines are new. It also seems to starve for fuel some times and other times it floods. Both carbs were rebuilt a few times with different parts - the latest being genuine Mikuni - no difference. Float level is correct and I even bought new floats. I have a ultrasonic cleaner and both carbs were cleaned using this - they are spottless. I have rebuilt and used Mikuni's for 30+ years and loved them, but not in this Attex.

So anyways, I am done with these Mikunis and I have a JLO with a Tillotson car and intake on it. I am considering swapping it and removing the external Mikuni fuel pump. I assume this is from a snowmobile so will have have jetting issues? Also, there is no insulator between the intake and carb - will I have vapor lock issues? Thank you!

[dave phelps]

I have had the same issues with a mikuni carb myself. I put new needle and seat and such. Still flooded the engine and carb. Put a new mikuni pump on it and my issue went away!! I can't answer it but that is what fixed it and I haven't had an issue since. As far as the tillotsons go I've never been able to make one run good using one.
Good luck whichever way you go.

[budzinsk]

Thanks. Yes I think I saw your post and that made me try a new fuel pump but no luck...