SX/SXi/SXi Pro Just got my SXI and have questions, where's the balls?

[Keithfa]

I just bought an sxi from a post on here. It's a super clean ski. The motor is 1 over, pjs 180psi head, coffman's rocket exhaust with no silencer (loud as hell!) aluminum flywheel, r&d timing advance, MSD enhancer, 48mm single black jack, everything is ported, and a 12/17 skat.



I rode it for the first time this weekend. When I am in the surf I won't care about the noise, but I'll for sure piss off everyone on the lake. Does anyone know where I can get an inline silencer? I've looked and they seem impossible to come by.



Most importantly, where is the bottom end? It pulls super strong mid range, but the bottom end is a joke. My brother's fx1 pulls way harder out of the hole. I did some reading last night and on the group k site it says that Kawasaki advanced the timing on the 98+ 750's electronically. They say it's "dangerous" for the timing advance plate to be on my ski. So my first question is can I pull the flywheel to get the plate off with the motor in the hull? Is there room? Second question is could, this fix at least some my bottom end problem?



There is no doubt the motor has power, but I can't believe it lacks that much throttle response. Any other suggestions? pump clearance looks good. It doesn't rev then hook, it just takes its time to rev. I messed with the low speed mixture screw all day and could never get it any better. My dad's 94 xi with a FP and a skat pulls harder and it weighs twice as much! Am I missing something?

 

[Crab]

When your ready, I can fab you a conversion bedplate to run a 701 in there......:beerchug:

 

[gorilla]

what year sxi did you get ???
i just got a stock 95sxi.
you could try putting a stock 750 flywheel back on it.
it's possible the timing on that alum flywheel might not match up the timing advance plate's curve ???

good luck

gorilla

 

[Big Kahuna]

unfortunetly, the Kawi's are not known for having strong bottom end power. Electronic Waterinjection may help to bring in more bottom, along with a shorter pitch prop.

 

[Crab]

Small pin cylinder is best for bottom end, I have an extra and a new msd water injection if your interested.

 

[shawn_NJ]

The 96 sxi motor I dropped in my X2 2years ago was a dog on the bottomend. It had a Bpipe, 185psi, and 4deg timing advance (K650 elec), lightened 650 flywheel, ect. I have another X2 with a small pin 750 that only has a coffman pipe, and it stomps the big pin sxi on the bottomend. Both have same 46mm carb. But to be fair the SXi was downright scary on the topend. It was FAST!

That said my 62T/61X powered X2 pulls much harder then both the kawi motors on the bottom end.

 

[N3vrSat1sfied]

the MSD enhancer is not suppose to be ran with a timing advance plate! It over advances the timing leading to bad things. Take the plate out or order the MSD retard Module for the 750(thats how mine is).

I put 8/16 swirl big hub on my ski and it really made it wake up on the bottom still not a 701 but way better then before!

 

[jondotcom]

Besides removing the timing plate, how many pissers are you running? If you have double pissers you might divert one into the exhaust.

 

[GReenANt]

although i could always use more power i must not have any idea what i am missing because with only a factory wet pipe on my 98 sxi it feels pretty powerful to me. The pipe really only hits around 1/2 throttle maybe its ported and i dont know it or i have just gotten used to where the power is

 

[jondotcom]

I just bought an sxi from a post on here. It's a super clean ski. The motor is 1 over, pjs 180psi head, coffman's rocket exhaust with no silencer (loud as hell!) aluminum flywheel, r&d timing advance, MSD enhancer, 48mm single black jack, everything is ported, and a 12/17 skat.
?

Seriously, there are so many variables going on that it may never run right. Who did the porting? If it was group k that's one thing, but if it was "this guy's buddy" that's another.

 

[upstand2]

Actually a MSD enhancer is made to be run WITH an advance plate AND a retard module.
I've had this set-up on 3 750's never a problem. Most people have problems becauase the run high compression without the retard module. I know that sounds like it makes no sense but the module only pulls out timing at higher RPM's.

 

[N3vrSat1sfied]

Actually a MSD enhancer is made to be run WITH an advance plate AND a retard module.
I've had this set-up on 3 750's never a problem. Most people have problems becauase the run high compression without the retard module. I know that sounds like it makes no sense but the module only pulls out timing at higher RPM's.

Right the MSD with timing advance plate and retard module (thats how mine is as well with 195psi in eash cylinder)
OR
MSD with stock Pickup position (ie No adv. Plate)

 

[upstand2]

But without the advance plate the low rpm timing is waaaay retarded compared to stock.

 

[N3vrSat1sfied]

hmm. Never ran mine without since the screws in the timing plate are very perminet!

 

[Keithfa]

Thanks for the replys. I'll try pulling te plate off first. This is the firstI have heard about the retard module. Can somebody give me a link to it? The boat has 2 pissers but one is alreday diverted to the exhaust tail cone. It has a manual adjustment on it as well. Should I try maxing out the tail cone injection to see if I increase some back pressure? I do have an MSD ECWI setup that I just pulled off of my XP. Unfortunately I wouldn't even know where to start. Injest the headpipe, only the tailcone?

 

[N3vrSat1sfied]

http://www.jetskimechanic.com/store/commerce.cgi?product=parts_msd&keywords=&next=25

retard kit is about half way down.

 

[Scorn800]

What rpms does it start to pull hard?
May want to try a lower pitch prop and/or larger exit nozzle size

 

[sxi4evr]

brand new, never used... you want it? and we had a 12/17 prop in my dads 750, i didnt ride it but he said stock was better for bottom end. im runnin a skat 10/18

 

[ImpactSportsTV]

where is the bottom end? It pulls super strong mid range, but the bottom end is a joke. My brother's fx1 pulls way harder out of the hole. My dad's 94 xi with a FP and a skat pulls harder and it weighs twice as much! Am I missing something?

First off, Kawis CAN be made to pull plenty hard - yes, it takes some doing, but can be done.

There are two additional areas I would suggest you explore: The 48 BlackJack carb tuning, and your pump. I have had several BlackJack carbs and LOVE them, but 48s are by far the toughest to dial in. Talk to Art at JetWorks - they are his brainchild. 949.548.5259 - I know you mentioned that you adjusted your "low speed screws" which are actually idle mixture adjustment screws, but they are just the beginning. If you aren't up to dialing in carbs in, have someone that knows Blackjack carbs do it. They like an unusually high pop-off pressure for a performance carb - I'm running dual 44s at 26.5psi pop-off. The bottom line is that you can't just bolt a 48 Blackjack on - it WILL need to be dialed in. I have seen SEVERAL skis that ran like dogs simply because the carb was out of wack.

As for the pump... it's a longshot, but years ago, my 750 got REAL lazy off the bottom, Great mid and top, but no bottom. I tried EVERYTHING with no luck - swapped electronics, carbs, adjusted the water injection - all without results. Then once when I pulled the engine to swap it with a known good one, I noticed that the driveshaft was super hard to turn... the wear ring in the pump had developed corrosion between it and the pump housing that "bulged" it up into the side of the impeller. I had Skat-Trak replace the pump wear ring and all was right with the world. It's worth a check, especially if it hesitates a bit when trying to start it.

Good luck!

 

[Keithfa]

I already shecked the pump, I have had pump issues on other skis before. Everything sppears to be fine on this one. Thanks for Art's info I'd definitely like to find out what he has to say.

I don't have a tinytach so I don't know when it starts to pull. If I had to guess I'd say 3,500ish.

Does the flywheel have to come off to take off the advance plate? AKA am I going to have to pull the motor to get the thing off?

I think a lower pitch prop is definately worth a go. Anyone