Jetting baseline?

[twoares]

Here is what I got,

86 250R with the following...

FMF fatty pipe with power core II silencer
Vforce Reeds
Uni filter with factory box and lid on
32:1 with Maxima 927 oil
stock motor and carb
170lbs of compression
gas mix 50/50 using 92 oct with track tek 110 race gas

I run between 50-75F at 400ft+/- elv.

main is a 140 and the needle clip is on the 4th groove.

Top end seems fine but low-midrange is very choppy and i cannot figure it out. If I hold it half throttle and cruze it will not run smooth, jerking and stumbling. Also the carb idle adjustment is not very consistent to changes and the air screw doesn't seem to make any difference 1 3/4- 2-1/2 turns out.

I just got the quad about three weeks ago so I am trying to get a starting point.


Any ideas or suggestions are appreciated.

[screaminta]

your main is way tooooo small!!! Stock they come with anywhere from 155-160 mains. I had an 86 with basicaly the same setup, and I was running with a 158-162 depending on the weather. What pilot do you have also I would suggest to start with a 50ish and go frome there? Sounds like your needing some more fuel in the mid if you are jerking and stumbling. If it were me, I would get a 160 main and starts doing plug chops ASAP!

[gandgracing]

If your not getting consistent idle and no change with the airscrew I would say your pilot is not right along with your main. If that carb is that far off I would also make sure its got the right needle.

[twoares]

That's what I thought, it seemed small. I will try a larger jet and see what it looks like.