2009 GTX iS 255 ltd Performance / Top speed issues?

[dannyz]

Hi I have a 2009 GTX LTD 255 iS Seadoo. 75 hours on clock.

Now, i am new to jet skis in general, but I am concerned about the performance of my machine. I have noted a few things that don't seem right. Any advice would be greatly appreciated.

firstly there is no sport or touring mode for my ski, apparently in 2009 they didn't have this option. Generally it feels very powerful and rides great..


1. Top speed seems to be lacking, I have been told I should easily reach 100kph+ (60mph+) easy on the flat water i can not seem to get past 95kph on flat with 1/2 tank fuel, 75kg rider weight, VTS nose up or down. Speed is off skis speedo, will try using iPhone app next time.

2. From stand still and low speed FULL take offs, it feels like it stays still and revs out like doing a burn out in a car.. for a good 5 seconds before it gets up enough steam to go.. Like its hitting rev limiter if that makes sense. Otherwise when I'm cruising at a decent speed above 30/40kph and full throttle it it picks up steam very rapidly.

3. Sometimes the throttle feels dull and sometimes its super sensitive.. i can be cruising and on normal circumstances pulling the throttle ever so slightly reproduces different effects.. Sometimes it just picks up steam and feels a bit dull, still fast mind you! But sometimes the slightest of finger movements reproduces a RARE thrust that scares the s#*t out of me and feels like it should if that makes sense.


I am just curious to hear peoples thoughts on this and maybe diagnosing any problems if that. I was thinking is the throttle body not right? wear ring maybe? or even the supercharger needs rebuilding?


Danny

 

[Spimothy Leary]

1. Use gps not the speedo for accurate speed.

2. Check your pump. I suspect the wear ring.

 

[Coastiejoe]

Though 60 plus is correct, the plus part is minimal. 65 is a realistic and pretty consistent max speed for the 255.

I'm sure you will find your wear ring is this issue. Is the gap bigger than the width of a dime? If so, replace the wear ring. Does the impeller look good or does it have some songs and dents or a bent blade? Do you get water in the hull when riding? If so, probably the carbon seal. If you do get water, then you are likely sucking air into the impeller which would also create the issue you are having.


Sent from my iPhone using Tapatalk

 

[dannyz]

Yeah, no water in hull after rides at all.. Will look at wear ring/impeller when i get home this evening..
Thanks for your advice..

 

[dannyz]

Getting a full service, new wear ring, new solas prop and also the supercharger rebuild as its close to 80hrs now..

So hopefully this helps... fingers crossed, will report back!

 

[red2blue]

why are you adding a new prop?

 

[dannyz]

I was advised to change it as it has some nice dings/dents on it...

 

[jhjesse]

I just purchased this same ski about three months ago. I can get about 68mph on GPS. Throttle response is crisp and...well holy crap it is quick.
Things I would check are the exhaust manifold cooling hoses and make sure no leakage, cracks or signs of overheating due to a stopped up elbow fitting going into the manifold. (Ask me how I know) I would pay special attention to the cooling hose coming out of the IBR feeding the exhaust cooling hoses. Mine came off and filled my ski up with water because the hose clamp wasn't tightened properly.
I would also periodically check the small screen on the left side of the jet pump (inside) that feeds the cooling water directly to the IBR for blockage.

 

[dannyz]

exhaust manifold cooling hoses and make sure no leakage, cracks or signs of overheating due to a stopped up elbow fitting going into the manifold. (Ask me how I know) .

Soooo, how do you know?? Interested to hear!

So would any of these issues though reduce speed and acceleration and cause cavitation?

 

[jhjesse]

Soooo, how do you know?? Interested to hear!

So would any of these issues though reduce speed and acceleration and cause cavitation?

Will not cause cavitation just things to watch out for.
Purchased mine used from a dealer. Dealer had replaced the IBR but did not get everything tightened causing leaks and eventually a cooling hose to come off. During that first ride after purchasing the ski, the ski suddenly died and exhaust temp light came on. It then filled with water. Got it to the ramp, drained the water and eventually got it home. Started taking it apart to dry it out and found multiple hose leaks as well as clogged elbow fittings on the exhaust manifold.
Got everything fixed and it runs great now. Several people on another forum informed me as to what to look out for and should periodically check everything while running it on the hose. The PO must have ridden in weed infested waters.
Not trying to scare you just giving you things to watch for. A good flush and minor inspection after a day at the lake will prevent this from happening.
New wear ring and prop on yours and it should run like a bat out of hell.

http://www.seadooforum.com/showthread.php?80886-2009-RXT-IS-melting-exhaust

 

[dannyz]

Thats pretty frightening, and disheartening on a newly purchased ski..

Have mine back, haven't had a chance to take her out yet, but prop had 3 nice dings in it and the wear ring was worn slightly.. Supercharger has been rebuilt and a full service!! should move along well now hopefully..

 

[Spimothy Leary]

Thats pretty frightening, and disheartening on a newly purchased ski..

Have mine back, haven't had a chance to take her out yet, but prop had 3 nice dings in it and the wear ring was worn slightly.. Supercharger has been rebuilt and a full service!! should move along well now hopefully..

to be honest that story above is common, or some variation of it...
I bought a 2008 from a friend of a friend, and ski was very clean and even test rode it with no complaints, but after it was looked at carefully the week after I had a bad carbon seal, pto bearing, crankshaft, no oil in the pump and a questionable wear ring, I was taking on more water than I liked. Basically it was about a year or two overdue for a once over.

I really think the combo plate of wear ring/prop is the likely culprit based on what you described, take it out and see what happens, and don't use the speedo as anything more than a guideline, gps is the only way to know for SURE what your speed is.

you should feel very very little hesitation when you hit the throttle, and it should pull slightly harder in the mid range when the ski has enough time for the SC to start to spin up, then it should be a consistent hard pull right up to 65ish.

 

[dannyz]

Well BAD news guys!!!!

Picked up my ski Saturday after the new prop, wear ring supercharger rebuild and service. Yesterday I decided to take it out for the first ride.

SHORT STORY:
Jet ski Sunk and engine died within 90-180seconds of putting it in water.

LONG STORY:
Wanted to test it all out and see how this prop and supercharger rebuild performs. Back the ski into the water, (bungs closed of course) push it off the trailer and jump on.. Starts without hitch and ride it 30meters towards the pier whilst my old man parks the car. Half way to pier the engine splutters and dies and can not be restarted, me wondering what the hell has happened continues to try restart it 2-3 times with no avail.
30 seconds later i had floated to the pier and just tie up. realising immediately that i feel a bit low in the water i see its taking on water VERY VERY quickly and within another 30-60seconds its completely ass down nose up FULL of water.
All this happened again within less then 2 min.
Luckily enough it did happen so suddenly, and only in the marina, and not out in the ocean.
The guys at the marina helped out amazingly, towed it to other pier, put it on a boat fork lift, drained it and put it back on my trailer...
One thing that we noticed was that all the water was pouring ALOT out of the jet pump area (is it a jet pump seal or something to take on and vice versa pour out so much water so quickly?)

Regardless, i took it within the hour back straight to the workshop and they are dealing with it.. They were great about it and said they will sort it out, and apolegetic.. Lets hope they take full ownership of problem however significant it is. 2 weeks prior to this full work/service i was out on the lake/river and it was flawless for 2 whole days without a drop of water in hull..

What could it be? and I'm really worried about my motor now? is that stuffed? I tried to crank it after all water was drained, started for 20 seconds then died, so i just left it...

 

[jhjesse]

They should:
Pull the hoses off the supercharger and intake, then clear out any water in the intercooler, supercharger and intake manifold.
After getting all the water out of the intake, pull the plugs and crank the engine over to get any water out of the cylinders then reinstall the plugs and get it to start. Once it starts then any remaining water will be burnt off or expelled.
I would have them pull the dipstick and look to see if the oil is milky. If it is then it will need to be sucked out and changed probably several times before clearing all the water out of the oil. Hopefully it is clean.
Since they removed the jet pump I would guess that the pump hose going from the jet pump to the IBR through the hull wasn't tightened, but I am only guessing.

Sorry for your bad luck.

P.S. If the are worth their salt, they will unplug all electrical connections one at a time clean and reconnect using dielectric grease.

 

[benjilafouine]

Did this happened in fresh or sea water? It sucks. I hate dealers.

Benji.

 

[dannyz]

It happened in salt water..

Thanks for the info... Let's hope all is ok.

 

[Spimothy Leary]

maybe the carbon seal popped ?