Off idle bog weird jetting

I bought a 98 Superjet last weekend with a B Pipe, head, and msd enhancer.
It will bog and stall if I whack the throttle wide open from idle. It still starts easy, idles good and runs pretty good aside from having to have it above 1/4 throttle before I nail it.
First thought was popoff is too high causing off idle lean bog

I ordered carb kits + 1.5 N/S + 80 & 95 gr springs.

Took them apart last night to find:
#1
82.5 Pilot
135 Main
2.0 N/S
Yellow spring (maybe gold?)
33 psi Pop off
3/4 Low
1 1/8 High

#2
82.5 Pilot
135 Main
2.0 N/S (needle slightly worn)
Yellow spring
30 psi Pop off
7/8 Low
1 High

I know factory pipe says use stock 70 pilots, 1.5 N/S, 95 gr springs 135 mains. Stock airbox on this ski

What's with the big pilot jets & needle/ seats? Can anyone make sense of it?
 
Am I probably mistaken in diagnosing it as a lean bog? Rich seems much more likely with those pilots and 2.0 needle & seats.
I've been around for a little while and rebuilt a handful of carbs with good results but I'm still no tuning expert, usually I just follow the advice of someone smarter and fortunately for me they end up being pretty close to spot on.
 

Quinc

Buy a Superjet
Location
California
Am I probably mistaken in diagnosing it as a lean bog? Rich seems much more likely with those pilots and 2.0 needle & seats.
I've been around for a little while and rebuilt a handful of carbs with good results but I'm still no tuning expert, usually I just follow the advice of someone smarter and fortunately for me they end up being pretty close to spot on.


It is hard to tell between rich and lean without practice. Helps to troubleshoot using a choke or squirting in fuel with a primer. I am currently running dual 38's on a 754cc engine with all the bells and whistles and I am running 38psi with 72.5's and 135's with a/m flame vortex flame arrestors.
 
It is hard to tell between rich and lean without practice. Helps to troubleshoot using a choke or squirting in fuel with a primer. I am currently running dual 38's on a 754cc engine with all the bells and whistles and I am running 38psi with 72.5's and 135's with a/m flame vortex flame arrestors.

Yea if you're still good on 72.5 pilots I doubt this assumed to be stock 701 defies the laws of physics and needs 82.5. I also read mikuni recommends using the smallest needle & seat possible to achieve pop off and also the 1.5 flows as much fuel as the sbn is capable of
 
Update: installed the 70 pilots 1.5s and 95 gr springs, ended up using 80s but at fp recommended low adjusters position it had a bad lean bog. This time I'm sure it was lean because I turned them out more and more and it got better. Forgot to measure them but maybe an extra 3/4 turn out it runs great now :)
 
Top Bottom