Sanity check on jetting

[302much]

750SX Big Pin, new to me, bought it not running.
Dual SBN 46s
R&D intake
Ocean Pro swirl Head @ 180 Psi
Factory dry pipe With ECWI
MSD Ignition enhancer
V-force reeds
looks like its had some port work
stock bore ( i think, havent measured yet)

What it had:
2.3 N/S @~25 Psi on both carbs
122 High on both carbs
100 Low on front
110 Low on rear

i have never seen this run, the person i bought it from said it ran great, whatever that's worth..
The dry pipe literature from factory lists:
1996-2000 750SXi & SXi Pro (mikuni carbs)
Main Jet : 172.5 front, 170 rear
Pilot Jet : Stock
High speed screw : 2 turns out from closed
Low speed screw : Stock
Needle & Seat : Stock
Spring : 65 gram spring
Notes: Stock compression and timing

does the jetting i currently have sound right to you guys?

 

[Vumad]

I dont know what you jetting should be, but that motor comes with way smaller carbs and i think a different brand (38mm keihens i think) so facory pipe specs are irrelevant.

My x2 has a similar setup, 44s with a wet pipe. I think im something like 120/115@20 but i cant remember exactly. I was still tuning it when i took it apart for more mods.

 

[302much]

thanks, I see that the 96+ skis had mikuni I series carbs, and not SBNs (per group K). I don't know what those are so it may be the case that the jets aren't comparable.

Your X2 was a 750? what size needle and seat? i would think 2.0 would be plenty, but i don't know if having it to big is a problem, as long as the pop off is right.

 

[Magyar68]

You ride Lewisville? either way we have a Crew that ride out of Lake Park, a lot of knowledgeable guys. I have much the same setup, and a set of the I Bodys we could test it out with. PM me if interested.

 

[302much]

Ive been to Lewisville many times, at lake park too, i live in Denton so i usually ride there, but that past couple of years i haven't been out much. you might remember my last ski, it was a 650 with a 'Murica paint job. have y'all been out yet this year? we finally have some water now.

 

[Magyar68]

Shoot yea, I Rode through the entire winter. PM if you want to swing by a little south (Lewisville/Carrollton line) well get it running rite.

 

[Vumad]

thanks, I see that the 96+ skis had mikuni I series carbs, and not SBNs (per group K). I don't know what those are so it may be the case that the jets aren't comparable.

Your X2 was a 750? what size needle and seat? i would think 2.0 would be plenty, but i don't know if having it to big is a problem, as long as the pop off is right.

Puyting my x2 back together so i checked what was in it...

Sbn 44s, Front is 122.5/120@18 and back is 127.5/120@18. Again, this is just close, i need to change my prop down a pitch and do more tuning.

Yes, 750 big pin, factory wet pipe using a superjet chamber and superjet waterbox. 180 psi compression.

2.0 needle and seat with 65g spring.

Been a lot of adjusting i didnt have good baseline specs for motor, carbs or prop.

 

[302much]

Shoot yea, I Rode through the entire winter. PM if you want to swing by a little south (Lewisville/Carrollton line) well get it running rite.

nice, i work in Carrollton. I'm rebuilding the ski right now, just got done with paint, hopefully ill have it together in a few weeks, i have all the stuff to finish, minus some ignition stuff.

 

[302much]

Puyting my x2 back together so i checked what was in it...

Sbn 44s, Front is 122.5/120@18 and back is 127.5/120@18. Again, this is just close, i need to change my prop down a pitch and do more tuning.

Yes, 750 big pin, factory wet pipe using a superjet chamber and superjet waterbox. 180 psi compression.

2.0 needle and seat with 65g spring.

Been a lot of adjusting i didnt have good baseline specs for motor, carbs or prop.

ok, what i had doesnt seem too far off, based on this and some other stuff i have read. im gonna put it together with 125/110 and 2.0 NS @ ~25psi and go from there

 

[Vumad]

Just go slow, you may be lean there. You have bigger carbs and a hotter pipe and my numbers are a starting point for you at best. make sure you arent too lean before you start tk pin it.

 

[302much]

So I'm out at my buddy's lake house. A few days ago I went to dales jet sport to pick up some bigger low speed jets. He reccomended I up my pop off to 30 and Run 125 lows as a start. I Put it together with 1.5ns and 32 psi. Cheked both carbs with a pump. I put a 10-16 hooker and my x2 nozzle on.. the ski had no bottom end right now.. it sucks cause I changed both things at the same time... I think it's lean on the bottom .When I turn the screws in it seems to get worse.. should I put the 130 lows I have in?