Carby Keihin carb clone

[Jeffrey gagnon]

After doing some more test runs i found out some info now what i found out is the exhaust pipe the longer the header the leaner it gets now i beleve you said you had expansion chamber which is shorter then my flex fit exhaust that i have i found this out by running my stock nt carb and still had no throttle from 1/2 up which i know my stock carb was running great so i will be doing my next set of test runs with stock exhaust and aftermarket carb really think shes going to take off like a rocket at least thats what im hoping

 

[Jeffrey gagnon]

Oh and im running 4 1/2 onces oil to 1 gallon gas 32/1 basically i just add extra half once oil

 

[Jeffrey gagnon]

this is the spark plug i run

 

[Jeffrey gagnon]

Ok so this may sound like a dumb question but if my spark plug is gapped too loo that would effect the performance i pulled my plug it was gapped at 0.10 where i think recommended is 0.28

 

[Deleted member 12676]

Jetting rules:
first set the idle mixture and the full throttle mixture correctly
then adjust the slide cutaway for off idle power, and the needle height for acceleration as you are opening the throttle. It's possible you may need a fatter or skinnier needle if the adjustment isn't enough.

losing power when you quickly open the throttle is because the needle is too low (lean) or too fat.

 

[Deleted member 12676]

set the gap to .28 and if it won't start the engine then lower the gap.
for good low end power you want as wide a gap as possible

 

[SRPM]

After doing some more test runs i found out some info now what i found out is the exhaust pipe the longer the header the leaner it gets now i beleve you said you had expansion chamber which is shorter then my flex fit exhaust that i have i found this out by running my stock nt carb and still had no throttle from 1/2 up which i know my stock carb was running great so i will be doing my next set of test runs with stock exhaust and aftermarket carb really think shes going to take off like a rocket at least thats what im hoping

I don't have an expansion camber it's just the stock exgaust off my old engine.

 

[skyash]

Mine is a 2inc long drag pipe I think to some extent the quicker the air is out the better. But still it's what works for your bike

 

[Jeffrey gagnon]

So after putting stock exhaust on bike took off like a rocket was able to get the bike to idle high so i still have some minor adjustments on the carb but once i get that tuned in correctly then i can try my exhaust again and see how much it affects air fuel ratio and make my final adjustments to carb. Was reading somewhere that its best to tune in the carb before you put an aftermarket exhaust on but again i think my issue was the spark plug gapped way too low

 

[SRPM]

Mine is a 2inc long drag pipe I think to some extent the quicker the air is out the better. But still it's what works for your bike

You actually want some back pressure it keep the next air/fuel charge in the combustion chamber that's why you should have an expansion camber exgaust.