- Location
- Idaho
From my picture above, you are running the same pipe? If so, stock manifold? And waterbox or muffler. Mine sounds so loud. Where did you get replacement jets? Im also not sure how ill know what size ill need
coffman Pipe on 750sxi
- Thread starter Ryan Stewart
- Start date
From my picture above, you are running the same pipe? If so, stock manifold? And waterbox or muffler. Mine sounds so loud. Where did you get replacement jets? Im also not sure how ill know what size ill need
Pipe looks very similar. Mine has a J tube that allows use of the stock waterbox. Not much louder than stock. Atlantic jetsports has the Keihin jets. Read the factory pipe specs they recommend:
1995 750SXi
Main jet : 125
Pilot Jet : 75 (Stock)
High speed screw : 3/4 turn out from closed
Low speed screw : 1 2 turns out from closed
Needle & Seat : Stock
Spring : Stock
Comment: Stock spring shortened to produce 20 psi
1995 750SXi
Main jet : 125
Pilot Jet : 75 (Stock)
High speed screw : 3/4 turn out from closed
Low speed screw : 1 2 turns out from closed
Needle & Seat : Stock
Spring : Stock
Comment: Stock spring shortened to produce 20 psi
- Location
- Idaho
So ill need to buy two 125 high jet screws. One for each carb. Leave low speed screw stock. Then change the turns to 3/4 high and 1 turn low. And start tuning up and down from there? Im just curious on how ill know from tests if a larger or smaller jet screw is needed? Throttle excelleration in mid range?
- Location
- Idaho
Pdf is a bit scrambled on my pc. Does that high speed screw say 1/2 , 1, or 2 out from closed.
- Location
- Idaho
Emailed coffman.
Unfortunately, the Rocket pipe is not designed for the SXI. The port timing is completely different. Sorry we are unable to assist.
Kind Regards,
Pam Coffman
Am i screwed, should i buy a new pipe setup? Or follow what you recomended since they are similar
Unfortunately, the Rocket pipe is not designed for the SXI. The port timing is completely different. Sorry we are unable to assist.
Kind Regards,
Pam Coffman
Am i screwed, should i buy a new pipe setup? Or follow what you recomended since they are similar
- Location
- Two Rivers WI
Ryan, keep the pipe. I just put one on my SXI. Jetting is 95% there. Here are my specs:
95 SXI
125 main
85 pilot
1 turn out each screw
Spings cut 20psi
Mine runs awesome, just loads up when I fall off. I am trying a fcv and/or 40g springs if that does not fix it. At this point im not sure if the pipe is getting too much water or if its dumping fuel due to too low popoff.
95 SXI
125 main
85 pilot
1 turn out each screw
Spings cut 20psi
Mine runs awesome, just loads up when I fall off. I am trying a fcv and/or 40g springs if that does not fix it. At this point im not sure if the pipe is getting too much water or if its dumping fuel due to too low popoff.
- Location
- Idaho
Bandit, you are a saint. my stress level just went down a notch. Im going to buy 4 jet screws based off what you just recomended. As far as the springs, how much do i need to cut off? I got new springs in a carb rebuild kit.
http://www.ebay.com/itm/1995-1999-K...ash=item4640d059f1:g:q38AAOSwT6pV5fwH&vxp=mtr
That is the kit that i bought, and i think it came with a few different springs. which i still have, although id have to check to see which one i threw in there.
PS. is yours loud? I was only at 8% throttle and it was emberacingly loud. almost to the point where i wanted to make sure no one was around me
- Location
- Idaho
Also, im seeing that most mods use 125 / 75. I think stock is 115 / 75. Is there a reason you went with 125 / 85. And i see that Kawasaki 750sx (non sxi) use 155 / 75. But youre farely confident that 125 / 85 is best?
Last edited:
- Location
- Two Rivers WI
Ryan,
I went with the 85 as that was required to get the motor started and to idle. With the 75, I got the ski started once on a full battery charge. With the 80, It could run but didnt want to idle very well. 85 was the ticket.
With my previous post, I should mention that the jetting specs I gave are for 6000ft. If you are near sea level, I would go a extra quarter to half turn on each screw. Also, I am running a restrictor in the waterline to the stinger.
I went with the 85 as that was required to get the motor started and to idle. With the 75, I got the ski started once on a full battery charge. With the 80, It could run but didnt want to idle very well. 85 was the ticket.
With my previous post, I should mention that the jetting specs I gave are for 6000ft. If you are near sea level, I would go a extra quarter to half turn on each screw. Also, I am running a restrictor in the waterline to the stinger.
- Location
- Two Rivers WI
Also, I looked at my springs. It looks like I have 40g springs with 3 coils cut off. I am not sure what spring is stock (40g, 70g) as it was cut by the previous owner.
- Location
- Idaho
Okay, im at a lake usually and its 3000 ft above sea level. And my jetski has slight hesitation starting up , and i often have to keep holding in the choke as it slowly starts to turn over, then as its turning over give it a few small throttle puffs of gas. So maybe im in the same boat as you. Ill go for what you are recomending. And ill try 1 1/2 turn on L and H to start it off.
Ill let you know how the 85 / 125 works.
Im kinda going off of this guide.
http://www.pwctoday.com/showthread.php?t=62278
Ill let you know how the 85 / 125 works.
Im kinda going off of this guide.
http://www.pwctoday.com/showthread.php?t=62278
- Location
- Idaho
Okay, As far as my springs go. I wont know how to judge which prings to use from the kit i posted above. And whats the que to cut springs off of them. I have a feeling i should look into that. any way to tell if i have a 40g and if ill need to cut springs?
- Location
- Two Rivers WI
I dont know of any way to tell without having both springs. Look at the two sets you have, if they are different, the shorter, more closely wound ones are 40g. I just realized that you are still using the stock F/A. Keep the springs stock and give it a try. I know its recommended to remove the trumpets and if you do that you may need to cut the springs a tad. Without a popoff gauge its all guess and check.
- Location
- Idaho
Ill buy a gauge to trim the closely wound set of springs to 20psi popoff. Nout sure what F/A or trumpets are though. Sorry for my ignorance. But your information has been like gold to me.
- Location
- Idaho
Oh. Stock float arm. Ya. Stock seating but new needle
- Location
- Two Rivers WI
F/A is flame arrestor. The part on top of the carbs that says TwinCarb 750. The trumpets are the rubber pieces on the side that allow the air to go in.
- Location
- Idaho
Alright. Ill remove those . Thanks for the tip. Hadnt looked into flame arrestors. Good to replace? Any reccomendations
You can run it with the carburetor cover off to tune , and l think you wanted to use your stock water box there the quietest generally ,good looking pipe it should perform , it may perform well l have no experience with it, but that resonator is the culprit for noise, tdr is loud aswell ,may wana try westcoast or get another stock one
Match the other carb up and see how it runs
Match the other carb up and see how it runs