Topic: Nikki two barrel carb issue

[crazycraftsman]

It's on my built 35 vanny. Not a big bore carb. When letting off throttle in corner and coming back on throttle it stumbles for a second , then pulls good the hole straight. It only happens if I let the rpm drop below 3500rpm. If I stay above that it doesn't stumble. With traffic it's hard to keep it above 3500rpm in the corner. Plugs are dark brown . Not soaked . Too rich or lean, low jet or main jet problem? Thanks for any info. I've opened lows and highs a couple sizes and didn't fix it.

[leman]

It kinda sounds like a lean situation... (You need a larger main jet)

When you'd floor it and it stumbles, does it go silent for a fraction of a second, then as the air flow would pull enough fuel through the venture, POW it would snap to life? ....... lean condition.

OR

When you floor it, it would bog down, then slowly stumble back to life like the engine bogs a little? .....rich condition.

[crazycraftsman]

That's a hard one. It's not bogging,more cuts in and out 1-3 times really fast then goes. If I start from a stand still and take it up to 7500 it doesn't do it. It's only hard off then hard back on throttle. What rpm does the low jets affect? Thanks for your help Nick

[George Herrin]

LEAN.

[crazycraftsman]

So should I open lows and highs a couple more sizes or just the high jets? Thanks for your help, it's appreciated.

[George Herrin]

It kinda sounds like a lean situation... (You need a larger main jet)

[crazycraftsman]

Thanks Nick and George

[crazycraftsman]

I've opened the main jets three times .002 at a time and now sitting at .046 tho- 1.17 mm . Plugs are now black but not caked or washed away. Nothing's changed. Do I still need more? Lows are .023 tho - .59mm. Idle jets 1.5 turned out. It's driving me nuts.

[George Herrin]

if plugs are black its not a fuel issue. Personally I think lows are too big. But thats me. I would start checking iognition. Plug gap, coil gap, timing, etc.

[crazycraftsman]

Beginning of the year , new motor.I opened the lows .002 at a time till I got rid of blue flames coming out of my exhast. There's  no black coming out of exhast when I let it idle for 15-20 seconds then rev it and no stumble. Plugs are gaped at 33. Lash .004 all. Tryed a set of coils with different harness. Runs awsome just that weird stumble. I'll try bring the idle up 500 rpm, richin up the idle jets?

[crazycraftsman]

Was able to put a stock bowl on with 30 lows and 101-99 mains and it ran night and day better. No more cutting out.  Guess I was going the wrong direction. Living & learning