SX/SXi/SXi Pro still life in a 14 year old ski? trying to improve performance (99 750 pro)

[JetSkiBrah]

in august of 2011 i picked up a 1999 kawi 750 sxi pro. loved the thing. all it had was a worx intake grate, and a little jerry rigged "2nd" pisser that some mechanic put on my water hose. Since then, ive put ODI signature grips on and a worx D cut ride plate.

I'm 6'0 and about 190lbs. i love carvin turns but most of all i love getting huge air off big waves out on the lake. my ski radar'ed in the high 48's and im completely happy with that (of course, more is welcome).

I've done hours and hours of research, all to contradicting results. What i've understood to be the most widely accepted, cheap upgrades is lightened flywheel, milled head, and the factory pipe products limited pipe (used). there is a used one for 500 in MI right now, but that seems kind of high. problem is, factory pipe will use my whole budget, wheras, i can get the head milled and flywheel lightened for 200ish.

so if you had a basically stock 750 sxi pro, what would you do first? given a budget of 500 but hopefully under 400.

i know theres tons of threads on this, but i couldnt find a recent budget sxi pro thread. prices change. availability of parts change. what do you guys ( i consider experts) think is the best route for me to go.

 

[TheBuzzard]

a pipe is the biggest performance bolt on mod you can do on a 2 stroke. that always gives you the best bang for the buck. if you put a 327 in a vega you gotta put bigger tires on it or it'll just burn rubber. put a stock SXr800 prop in there and call it a day until you get more $.

 

[TontoM3]

Yeah, the pipe will be the most noticeable. I had to go back to stock after my pipe broke and I was a sad panda for a little while until I learned how to ride the ski without a significant power increase. New miller is the guy to talk to about getting your head milled, and a big hub prop pitched to like 10/18. Also I'm assuming you have dual Mikuni carbs? If you get a pipe you have to re-jet those for the pipe.

 

[JetSkiBrah]

thanks for the replys. How much should i pay for a used factory pipe? I barely ever see them for sale. and is that my best option of pipe for overall power?

buzzard, are you trying to say the stock sxr prop is a more aggressive pitch than the sxi pro? if so thats great because i have a guy that parts out skis and regularly sells props for 15 bucks.

tonto, yes i have the dual mikuni's. 38's im pretty sure. whatever stock is.

speaking of carbs. where the hell are the adjustment screws. i was told theres a high and low, but all i find is the high. please tell me the low isnt sandwiched between the carbs..

 

[TheBuzzard]

$500 is a fair deal if its not beat down with frozen adj screws. i'm holding out for more on the last one i have. coffman pipes create basically the same power as factory, but are somewhat less reliable , but they can usually be found for less money. the sxr prop is a 13/18 big hub swirl and the sxi is a small hub straight blade 9/17 or 10/18. i sell stock sxr props to all the local 750 guys and they make a big difference. if its the 92-94 single carb sx and stock, the sxr prop is a bit too big. one of the low screws is going to be in between the 2 carbs.

 

[JetSkiBrah]

I have contacted the guy with the pipe, the top screw is frozen, so he says.

its a 99, dual carb sxi pro.
so the sxr prop will fit in my 99 sxi pro? i also know guys either bore the stock nozzle or get a 650sx nozzle. i think ill look for a 650 nozzle so i can keep the ability to return to stock.

 

[Dirtybird]

Also have a pipe for 750 all screws were replaced a few years ago and turn freely.
All mounts and parts are there except for water lines and carb jets.
Contact me if interested.
Thanks Brad

 

[JetSkiBrah]

I'm sorry, not very familiar with getting around on here. i cant find out to pm for the life of me..

 

[tor*p*do]

I'm sorry, not very familiar with getting around on here. i cant find out to pm for the life of me..

you need more posts

 

[tor*p*do]

I am running an old Coffman Lightning pipe in my 750sx
huge wakeup, almost as good as FPP, this and Coffman Rockets can be found
for $250ish; keep your eyes peeled

 

[JetSkiBrah]

Thanks tor*p*do, i went and posted in some random threat to get up to 10, and it just took a while to register i guess. its working now.

I'd be happy with a coffman as long as it's in good condition. Which coffman pipe would be comparable to the fpp limited pipe? in that it's ok for recreational use and relatively easy to setup and use without being overly picky on settings. whats the diff between the lighting and rocket?

are you guys using ECWI units with all pipes? i see people using them and some not, I dont really see the need other than fine tuning the water supply for a few more horses. but its also a few hundred bucks for those electronics.

I DID just win a bid on ebay for a 650 nozzle. i hope this helps a bit, keeping my eyes out for a sxr prop or used a/m one.

 

[TheBuzzard]

coffman rocket series is a cast pipe and adds big power. lightning series is a stamped chamber and a dry pipe. very rare and not that great. needs water injection to perform properly. according to coffman, the rocket pipe needs no jetting changes if used on dual carb models, just turn screws out. always check jetting, period!

 

[JetSkiBrah]

Thanks for the info, Buzzard, i searched craigslist, ebay, and several pwc sites and cant find a coffman for sale reasonably, so i think these few available fpp pipes are my best bet. is there a general rule of thumb jetting setup people use with the stock intake and fpp limited pipe? and what brands do you like, buzzard? im not mechanically inclinded enough to know how to "check" jetting, but i can install the new ones.

I just thought of a small issue, i live on a lake with lots of older folks and I'm sure they dont want some BRAAAAAPPP sounding machine ripping around the lake. I already try to stay off shore a ways, but is a fpp limited pipe going to make it THAT much louder? i have a buddy who has a 92ish 750sx single carb with a fpp and he claims he gets stopped frequently by the water officers. is there a way to silence them a bit?

 

[TheBuzzard]

the factory pipe uses the stock waterbox and isnt loud. if you get on factory pipes site, it gives the jetting info. i dont know it off the top of my head at the moment. i was going to say, go with the factory pipe. more money but less headache.

 

[tor*p*do]

http://www.factorypipe.com/media/instructions/kawasaki/750SXltd.pdf

 

[JetSkiBrah]

thanks for the info, tor*p*do. very cool info on that pdf. basically what i got from it, is they specify no change to carbs other than tuning if needed when using pipe and A/M flame arresters. now, I'll be using stock flame arresters to help keep water out, and because theyre simply not that bad stock. but i will take the silencers out to increase airflow slightly, as a/m arresters would.

Its good to know that it wont be too much louder.

are you guys using any aftermarket water injection systems? or am I ok to just bolt on the pipe, tune the carbs and go?

 

[JetSkiBrah]

tinkered around today. installed 650 nozzle and cleaned out airbox. messing around with the airbox made me think of two questions i have for you all.
1. i've seen people experience both good and bad performance after removing the silencer tubes from the airbox. what's the overall consensus on this? under what situation would it be advantageous or disadvantageous?

2. i've never had to adjust them so i'm not familiar with doing it, but how the heck do you adjust both carbs at the same time? are you supposed to remove the airbox completely to get to the front carb's low screw and rear carb's high screw?? i mean i thought you were supposed to be able to go ride a little bit, then throw it on land, pop the hood and turn a screw and slap the hood back on and test again.

the reason i ask is because last season it tended to start bogging a little bit when holding quarter or less throttle then pinning it. and today in the water it did the same.

 

[restosud]

get a dry pipe with ecwi.you won't regret it.worlds better than b pipe for about same $$

 

[sxi steve]

Hey, use my Pro as reference. I pretty much Awesomized it.

See the below signature link(s).

Along with engine and pumps mods. I believe a 'shortened handle pole' and 'Tubby 2s' are important and WELL worth the money!

 

[JetSkiBrah]

Hey, use my Pro as reference. I pretty much Awesomized it.

See the below signature link(s).

Along with engine and pumps mods. I believe a 'shortened handle pole' and 'Tubby 2s' are important and WELL worth the money!

thanks, steve. I've seen your ski alot on x-h2o and a really admire the setup you have. as of right now I'm a little short on money, but i might look at things like flywheel and head, the cheaper things. honestly my handling is pretty good. i'm pretty cordinated on the ski, i just want more instant grunt when i punch it from 1/4 throttle.

speaking of which, I just got off the lake, its a pretty windy day so there was some nice little 2-3 foot waves to play on. while doing so, a stupid nagging problem showed up that happend last season as well. i'll do my best to explain thoroughly..

start up the ski.. warm up the ski.. runs very good.. it never has any trouble at constant speed, and barely the slightest hint of what could possibly be hesitation when i punch it after being at 1/4 throttle. and usually, i just go to quarter throttle again, punch it, and then i dont notice it and just forget about it.

BUT.... after riding for half an hour or more, it begins to hesitate more and more noticably. this occurs especially while in very choppy water and while doing lots of back to back jumps, (and thus slightly more falls, so more time on its side). the hesitation gets so bad that it I can ride it on plane very slowly and punch it and stall it.

I also do know the whole thing about when just floating in the water, the engine struggles when rolled to the right, (im sure something about the carbs fighting gravity?), but towards the end of a riding session it seems to be much more prominent and eager to stall.

Lastly, when the engine DOES stall, or i just shut it off to take a breather, it isnt as eager to start. normally when cold, it will start right up no throttle, but after its been running, it takes just the slightest pressure on the throttle cable to start, and after running for an hour or so in this choppy surf, it takes more like 1/8 or more throttle to start.

Long story short, my ski seems to be more thirsty the longer i ride, as requires more gas to keep an idle, and also hesitates more (lack of fuel delivery?) when punching it from 1/4 throttle. hopefully someone can help me with this because i've done countless hours of research, but im a little thrown off when it seems to be properly tuned, and then losing that proper tune when riding in rough water and jumping alot.