2001 sportster 5900rpm max

[Sportster-2001-951C-Stock]

What pitch r u thinking? And will that not effect rpms?

I haven't decided yet b/c I've been too busy to research it but 11/19 or possibly smaller. I really don't want to give up my cruise speed and I only ski occasionally.

I will probably ski at least once again this year but first I need to clean the RAVEs again and if it can't pull me up a little better then I'll be looking for a smaller wheel.

Impeller size is really critical, chose wisely.

 

[shuka]

I will be giving you a call in the next week and we will see what we can do to fix this problem. Thanks again for everything

 

[Sportster-2001-951C-Stock]

The only thing i remember before impeller is the top speed was 47 and now its 42 and when i ski slolom i get up quicker now.

I also noticed that if the driver just nails the throttle in the hole (with my current impeller) the boat has less pull then if she eases into it.

With this impeller, nailing the throttle just results in what seems to be cavitation, easing into it this doesn't happen (when I'm on my slalom behind the boat).

I can lean back and the boat can't pull hard enough to pull the handles out of my hands unless the driver eases into the throttle. I don't think it's ventilation, more like cavitation.

So, without knowing exactly which impeller is in my pump it's a little confusing. But just knowing the LRV used an 11/20 also tells me the sportster will probably do better out of the hole with a slightly smaller wheel than the LRV used.

There's no telling what I might find in there when I do finally get around to pulling the pump, but it works fairly well except for the slalom pull is a little too weak.

 

[Bonmotwang]

I haven't decided yet b/c I've been too busy to research it but 11/19 or possibly smaller. I really don't want to give up my cruise speed and I only ski occasionally.

I will probably ski at least once again this year but first I need to clean the RAVEs again and if it can't pull me up a little better then I'll be looking for a smaller wheel.

Impeller size is really critical, chose wisely.

Weather is fading away here :-(
Last week was a chilly week. I hope I can still get a good week to go "faster".

Other wise I would be planning some fishing trips with friends on Grand River.

 

[Waterluvr]

So the jet ski guys aren't even to sure about that Solas st-cd 15/20 on a ski hull with stage two mods, that's pretty much a heads up on staying away from it for boat use. I can't link to the forum where I found the thread but they are clowning that idea pretty hard for the Sportster boat and they know their stuff when it comes to impeller mods.

There's 200 of them for every two of us, and they mod everything they can get their hands into and compare notes.

Google that Solas impeller model and Sportster, you'll find it on GreenHulk forum.

 

[shuka]

My wife slams full trottle and im up right away. If she eases into it i will just be gragged behind the boat and choke on the water.

 

[shuka]

They are saying do not use this on a stock engine so the mechanic did not do the research on the impeller before selling it to me. And i first said i wanted a stat trak but he said he researched and this one would be the best for my boat. WHAT A ASSHOLE and that shop has great reveiws. Should have knew there was going to be a problem when i asked him for a spare tire for the trailer and he gave me a 4 lug when i needed a 5 lug. I didnt check until i got home.

 

[Sportster-2001-951C-Stock]

Whatever it is, it simply can't be bigger than what it shipped with from the factory. If you go smaller then be prepared for a possible loss of top speed with a gain to the hole shot (this is my expectation).

Going with a larger impeller will drop your RPM's, and if the engine can't swing this impeller then it's guaranteed your top speed will suffer.

So why does the larger wheel pull up a slalom skier better than the original impeller? There are other things such as wear ring and carbon seal condition but I will just point out the impeller currently in my boat cavitates when I'm back there with my ski and the driver goes balls to the wall on the throttle. The only way I get a good pull is, if she eases into it.

So yeah, a bigger wheel probably doesn't cavitate simply b/c the engine can't spin it up and the net result is with no cavitation the boat moves. Oh, what about the carbon seal and wear ring, were those also replaced?

So there are numerous variables, a performance comparison against what's already been tried is the best approach.

So in my case, not knowing what's actually back there on mine, I'm inclined to want the OEM piece except that I know that piece was used by the OEM on even lighter vessels with the same engine.

This is why I want a smaller wheel than the OEM, although the one in my pump (not OEM) does perform adequately.

 

[Sportster-2001-951C-Stock]

My wife slams full trottle and im up right away. If she eases into it i will just be gragged behind the boat and choke on the water.

Yes, and my impeller is not the original either. So I really don't know how well the factory impeller performs except I do know they used that same impeller in the smaller LRV.

I do wonder though, when you had the new impeller installed didn't you also have other pump work done as well? If the engine can't spin the impeller that it won't cavitate so in that case it still beats a worn out pump but what if you actually had the optimum impeller for your boat and the pump was in excellent condition?

I can't say the OEM impeller isn't optimum for the sportster but the sportster is considerably heavier than the LRV was.

I wonder if your original impeller was cavitating or ventilating b/c the wear ring and carbon seal were worn out?

 

[shuka]

No the original impeller cavitated i just changed it because it was alittle beat up. It was not giving me any problems maybe just some low rpms/speed and it was hard to pull me up on one ski. I thought because i was getting work done i could change the impeller to help me get up easier. I did take it back because low rpms but he could figure out what the problem was.
He did the impeller, tune up, rebuilt carbs, installed tower, changed wear ring, and did compression test

 

[Sportster-2001-951C-Stock]

I tend to wonder if maybe you couldn't get a good tow b/c the smaller impeller was cavitating and perhaps a little less throttle (ease into it) would've made the difference?

This is what we have to do, else the boat practically sits there and cavitates.

So I dunno what's more important for you, it might be worth going back to the OEM impeller and maybe easing into the throttle so the impeller doesn't cavitate?

I feel like my impeller is smaller than your 15/20 b/c my RPM's are higher but all else equal I could stand for a bit higher RPM myself, and given the 11/20 was used on the LRV then the LRV must've revved higher at top speed than the heavier sportster.

So I think I want a smaller(by a small amount) than OEM impeller and if it does cavitate as does the 11/20 and the one I currently have then I'll just have to ask my driver to ease into the throttle.

As far as getting a better pull from the 15/20 balls to wall I can imagine that since the motor probably can't cavitate it.

So maybe the 15/20 isn't a terrible match from that perspective, but it sounds like it's not allowing the engine to reach it's power band.

 

[Sportster-2001-951C-Stock]

Weather is fading away here :-(
Last week was a chilly week. I hope I can still get a good week to go "faster".

Other wise I would be planning some fishing trips with friends on Grand River.

The weather is still great here and I expect to be boating until mid Oct., I just haven't had much more time for water fun than I did last year when we burned ~60gal of fuel in the sportster.

 

[Sportster-2001-951C-Stock]

shuka - I want to add, I'm glad to see you are taking over the maintenance of your boat yourself instead of taking it to a shop.

I will never take anything of mine to a shop b/c I've seen way too many examples of sub-par work and the litany of problems poor decisions causes. I see it everyday, people pay good money and receive sub-par service in return.

 

[shuka]

Do any of guys know what things need to be do for a proper tune up. Id like to check to insure that they all have been done.

I do trust that the mechanic actually did everything.

Any feedback what be helpfull

 

[Waterluvr]

Do any of guys know what things need to be do for a proper tune up. Id like to check to insure that they all have been done.

I do trust that the mechanic actually did everything.

Any feedback what be helpfull

When someone brings me a 2 stroke jet boat for a tune-up I perform the following, it has to pass a compression test within 90% of specification and I'll work on some that are within 15% with the understanding that the motor is at the end of it's useful service life and needs at least the top end restored to factory specs, I won't touch it again after that unless it's coming apart for an inspection and rebuild.

There's very little reserve horsepower in these boats as compared to ski's running the same power, you need all of it to experience a reasonable level of performance from the boat. The ability to place passengers and tow load on the boat in addition to the much larger wetted surface of the hull really takes it to task.

1. Compression check
2. Ignition check with a Stevens CDI tester
3. Charging system test
4. Rave valve/housing cleaning and repair as needed.
5. Complete disassembly, cleaning and rebuild of the carbs, accelerator and fuel pump with new kits and fuel supply testing for filtration and flow including the operation of the fuel selector valve. Carbs must pass leak and pop off tests before installation and the air box and filter are cleaned.
6. Adjustment of the throttle and the oil injection pump cables
7. Lubrication of the PTO shaft and inspection of the drive and wear ring / impeller condition.
8. Exhaust and all water lines are inspected for leaks.
9. Water test and tune carb adjustments, verify no cavitation issues from leaking seals and make sure the boat runs 100%.

Jet boats more or less are low tech/high performance toys that need everything to be right or the experience is lousy.

 

[Sportster-2001-951C-Stock]

Great list, especially like the water test. I really don't believe any shop can be certain the boat is in good running condition following a complete service without performing a water test.

 

[shuka]

Hey sportster 2001 951 Stock how do you pull a tube with your boat do you use ski pylon or the v type that hook to trailer tie rings?

 

[Sportster-2001-951C-Stock]

Hi Shuka, I would suggest using the stern eye for pulling a tube, or if you want to use the pylon then only extend it as little as possible.

The concern is, if the tube goes underwater it will probably bend the fully extended pylon.

Hey, I'm still thinking about your rpm issue, are your carburetor high speed mixture screws set to zero turns from fully closed position? I wonder if your air:fuel mixture is too rich....

 

[shuka]

I have never touched the adjustments on the carb. How do i check it and where do i find them?

 

[Sportster-2001-951C-Stock]

The high speed mixture adjustment doesn't change to rich by itself, so if you haven't adjusted them they should still be in the completely closed position.

Sometimes what can happen is during a carb overhaul those HS mixture adjusters can be left open by mistake, if they're confused with the low speed (idle) mixture adjusters.

So now I doubt that's the issue in your case since you haven't had the carbs off yet.

The HS adjusters are accessible from the bottom, underneath the carbs, at the end of the red lines in this photo, there's a black plastic limiter cap over the adjuster screw heads you have to remove by pulling it off with pliers in order to expose the brass screw head if you want/need to adjust them.

 

[shuka]

So it should be completly closed

 

[Sportster-2001-951C-Stock]

Yes, the specification states the position should be zero turns open from completely closed. I opened mine as a test and noticed the WOT RPMs began to drop off as a result, thus concluded the factory spec was correct and closed them as specified.

 

[shuka]

Hey one thing i do remember is when i took the boat back to the mechanic he said out of water he would get 8,000 rpm but in water 5900. But he could not figure out what the problem was. I dont know if that mean anything but just to let you guys know. Waterluvr i will be calling you soon sorry just have alot going on. Going to remove radio to send back to get replace. So i think without radio we wont take boat out to the lake so i will come by in the next coupke weekends. Thanks again

 

[shuka]

Yes, the specification states the position should be zero turns open from completely closed. I opened mine as a test and noticed the WOT RPMs began to drop off as a result, thus concluded the factory spec was correct and closed them as specified.

I just checked and they are open a 1/4 turn. Should i close them

 

[Waterluvr]

I just checked and they are open a 1/4 turn. Should i close them

Close your mag side, easy does it just seat it gently. Seat the pto side and back it off about 1/16 of a turn and water test it with new plugs gapped and installed.