1999 gtx rfi mods?

[0verkill]

im looking for suggestions for engine upgrades or mods for my 1999 gtx rfi. my goals would be top speed and overall power, and i have a few questions.
1. increasing the bore, helpful or not really worth it?
2. if there any type of power commander or anything to tune it?
3. anything in the way of a turbo kit?

 

[Spimothy Leary]

nothing worth exploring IMO, its a 787 GTX, just enjoy it.

perhaps a new impeller but not sure if its worth the investment.

 

[Sportster-2001-951C-Stock]

Forget it, go get a bigger ski if it's not enough. Personally, I like that motor and ski just the way they are and would be quite happy with it.

 

[KK40384]

1. Not worth it
2. No
3. No

You want a ski you can mod and go fast. The newer forced induction models is where you want to start looking.

 

[0verkill]

well i guess this is why i asked lol. i traded labor for it so im not into it for anything, i just like to tinker. the 84mm pistons would give me 820cc, maybe a little more grunt but i didnt imagine it would be much. the impeller is one thing i was interested in, they seem cheap and easy for a little extra top end. i had it out yesterday and it wouldnt get above 30 mph and suddenly at the end of the day i couldnt get over 10mph, the engine still revs to 7000rpm so it doesnt look like the problem lies there. im definetely leaning towards selling it and getting something more modern.

 

[griz400]

well, this ski was supposed to be a fuel efficient low emissions version, but the prop is a good mod, if it is reving at 7000 rpms, and your only going that fast, this is called cavitation and probably is a wear ring problem in your pump assembly, and isnt a real big issue to adress, look at the clearance between your impeller and the wear ring, it shouldnt be any bigger clearance than the thickness of a dime, (ideal being like about .010 ) and if thats the problem, no big issue, possible a carbon seal (that boot and seal where the driveshaft goes through the hull) , this ski with 1 rider full tank of fuel should be a mid 50 mph ski ... i smoked a new gt 155 this weekend ... lol

 

[0verkill]

well, this ski was supposed to be a fuel efficient low emissions version, but the prop is a good mod, if it is reving at 7000 rpms, and your only going that fast, this is called cavitation and probably is a wear ring problem in your pump assembly, and isnt a real big issue to adress, look at the clearance between your impeller and the wear ring, it shouldnt be any bigger clearance than the thickness of a dime, (ideal being like about .010 ) and if thats the problem, no big issue, possible a carbon seal (that boot and seal where the driveshaft goes through the hull) , this ski with 1 rider full tank of fuel should be a mid 50 mph ski ... i smoked a new gt 155 this weekend ... lol

so with a stock ski what impeller should i be after? 15/23? /17/25?

 

[griz400]

15/23 solas would be a good one with a new wear ring == 190.00 plus 50.00

 

[Mekanix]

Solas concord SD-CD-15/23, Awesome compared to stock on my 96 gsx 787. Hole shot is much better and it kind of jumps out of the water. Not sure top end is much better but getting there is.

 

[grinditout]

I put a west coast head with rec domes on mine and a solas imp, could not tell you if it is a gain or not, never rode it before the work.
looks pretty though.
Shows a strong compression of about 160 to 165.

 

[grinditout]

Also that ski is a money pit, took me about a year to find the parts at a reasonable price.
I know I will never be able to find the engine like I did again either. ( crate Brp )

 

[AdamXP800]

grinditout,haha are you the one trying to sell the "new" gsx rfi on craigslist for $5,000 in macon? Has to be, westcoast head, solas prop, crate motor BRP.

 

[grinditout]

You know, I put that add up about two months ago, with the expectations, that some "KID" would send me messages about how ridiculous it was priced and that one could be had for XXX somewhere else.

 

[AdamXP800]

Haha kid, grown man, woman, teenager, child... Anyone, will tell you how ridiculous that is haha I'm jk.
So what are you saying... You're not selling a NEW used ski for 5k?

 

[grinditout]

I would refer yout to the add; for more information.

This is a thread that belongs to the original poster, asking about mods for a RFI Rotax.

Feel free to share your mods to your RFI.

 

[Sportster-2001-951C-Stock]

grinditout,haha are you the one trying to sell the "new" gsx rfi on craigslist for $5,000 in macon? Has to be, westcoast head, solas prop, crate motor BRP.

I can get a brand new ski for that amount, or maybe a used 255hp monster ski? Likely not modified to full-race though!

 

[AdamXP800]

I want to buy your RFI! 5K it must be modded to the max, run 88mph and runs on purified water! Haha great ad! Again this is a NEW ski(only been run a few times, but new!