Super Jet starting point for single carb setup

[superjetnj]

Looking for a starting point for inital carb setup, 701 62t cases, 61x cyl,1mm over pro-tec head 180 psi, b-pipe limited, single 44 sbn on 650 kawi manifold with spacer, looking for starting point on carb set-up, sea level. Right now 147.5 H 115 L 1.5 ns, 95g spring, pop off 25psi, snappy off bottom, fat around 1/4 to 1/3 throttle, great on top for the ten second wot. seems to be loading up really bad in that low to mid area(1/3 to 1/2 throttle), where should I start, after riding this weekend, when I went flush ski, it had black crude oil coming out of the exhaust, like jelly.

 

[superjetnj]

Anyone?

 

[Midlake Crisis]

I have a very similar setup with stock Yamaha reeds.

Factory Pipe Instructions recommend
120 Pilot
145 Main
Stock (1.5) N/S
95g Spring - should get 25-30 popoff.

I was too big on N/S, low on popoff, too fat on main jet. I have dropped to 150 main but am going to order a 145.
I made really great progress getting everything as close to these specs as I could with what I had on hand.
Another big improvement was setting the idle with a tachometer and adjusting the low speed screw to get optimal idle @1100.
Smoothed out the bottom end a lot. Everything is much better but still loading up on the top end some, hoping the 145 main will help.

 

[superjetnj]

My ski will sit on the hose and idle all day long, it's just that transition phase where it loads up(cruising speed)just enough throttle to stand barely, or wide open is just fine, I guess I'll throw a 90 low, and 140 high in it and see what it does. I have low jets from 75-120, and all highs from 130-150, I'm just gonna start dropoping jets by 5. Was hoping to get a close starting point. It originally had a 2.0 needle and 18 psi pop off with a 150 h and 120 low

 

[rubbeerducky]

My ski will sit on the hose and idle all day long, it's just that transition phase where it loads up(cruising speed)just enough throttle to stand barely, or wide open is just fine, I guess I'll throw a 90 low, and 140 high in it and see what it does. I have low jets from 75-120, and all highs from 130-150, I'm just gonna start dropoping jets by 5. Was hoping to get a close starting point. It originally had a 2.0 needle and 18 psi pop off with a 150 h and 120 low

Did you ever figure it out, my ski has the exact same setup that your ski originally had and I'm looking for a good starting point...

 

[kevbo]

Looks like their Main Jets were way too big. I would go with a 120 Main Jet and a 115 Pilot Jet and Pop-Off in the 20's.

Set all your Low and High Speed Adjusters at 1-1/2 Turns open and Fine Tune from there.

Use a good Tachometer for Tuning.

120 mains on a single carb????

 

[kevbo]

I could use up to 170 with a single carb 701. He may figure it out or at least find his exhaust leak.

 

[kevbo]

I would set the popoff around 25 psi, tie the ski to a trailer and find whatever top adjuster/main jet it takes to get peak power. Then I would find whatever pilot that provides best response from 1/4 throttle. If anything changes with the hood installed then find the exhaust leak.

 

[superjetnj]

Yeah, old thread, I figured it out, been a while 137.5 main, 80 low, 1.5 needle, 95g spring I think is where I ended up, ski's not local right now, written on underside of hood