4500 rpm top out in water, 7000 rpm on trailer with hose

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Jweish

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I have a 99 seadoo gtx I was having problems with (my previous thread 99 SeaDoo Gtx LTD bogs on initial acceleration and once it hits 5600 rpm will drop back down to idle) so i rebuilt my carbs, changed all fuel lines and fuel selector valve. Recently cleaned and inspected rave valves and water regulator valve. Now the ski runs perfect (previous problem fixed) up to 4500 rpm but then it will just stay there without increasing rpm at WOT. I tried it on the trailer with a hose and easily obtained 7000 rpm at WOT
 
So I cleaned them about a month ago they were very dirty and sticking but now they move freely up and down.
 
That ski uses a RAVE solenoid to open them so even though they move freely doesn't mean they are opening.

Also what carb kits did you use?
 
I used the Genuine Mikuni mk-bn46i kits. And I put new needles and seats. I ohmed out the rave solenoid and got 29.8 ohms
 
But do you know if they are actually opening?
You can run it with the caps off to make sure they are opening but it will be a dog on the bottom end. With the caps off once you get it to about 5K rpm it should take off like a rocket.
 
Maybe there is a blockage or a leak in one of the rave hoses? I’ll check all the hoses for integrity and clear passages next time I have a chance. And I’ll try your suggestion of taking the caps off.
 
You won't hurt anything with the caps off but like I said, expect it to be a pig and stumble on the bottom end.
 
I removed the rave caps and it didn’t make a difference. Im going to test the throttle position sensor next time I get a chance
 
It didn’t make a difference, or it didn’t fix the problem? It should have made a dramatic difference running with the caps off, so if there was no change at all, you do in fact have a rave problem...
 
It made a little difference in how it ran but not when it comes to max rpm. The rave valve moved from an obvious down position to an obvious up position and the max rpms stayed the same except for a split second it went over 6000 then dropped back down and I could never get that high again
 
Where are the high speed mixture adjuster screws set? My 951 silver motor RAVES seem to come in about 5200 RPM and the throttle position switch is not until about 80% throttle, different year and different motor no doubt? but FWIW

Inspect the RAVE check valve too while you're digging for your gold, they do get gummed occasionally and this will give you no RAVE pressure.
 
I guess it could be a fuel issue still, my high speed screws are closed and my low speed are backed off 1.75 turns. I removed the hose/ check valve from from the engine to the solenoid and I leak checked it and verified proper operation of the check valve.
 
Does it fall on it's face and quit like it ran out of fuel and snapping the choke at the last second brings it back to life? If yes, the carbs are probably still dirty in the low speed circuit. That passageway is a lot harder to get clean than most anticipate, it's the single most important aspect of these carbs.
 
No that’s how it was behaving before I rebuilt the carbs. The first day after I rebuilt them it would run perfect but would only hit 4500 rpm then just stay there at wide open throttle. The second day it would go up to 5600 rpm and stay there for awhile but then after a little bit would drop back down to the 4K range. Haven’t driven it since
 
Haven’t been on in awhile so don’t know if this post will receive any responses, I finally got a compression tester and my mag cylinder was testing at 135 psi while my pto cylinder was only getting 115 psi. When I first start riding if I hold the throttle at wot it will run good up to 5600 rpm and then stay there, after about a min it will start dropping rpm and then start to run terrible (all while never letting go of the the throttle and holding it wide open the whole time).
 
That’s not a good sign with the compression numbers being that far apart. The 951’s do test a bit lower than the others, but they really should be even.
 
So I just did the test again but sprayed Xps lubricant in the cylinders first and my low cylinder jumped up about 25 psi, so I’m thinking my piston rings must be worn
 
The oil trick really doesn’t do anything for a 2-stroke. You have a cylinder on the way out.
 
the first test I did was on a warm engine without open throttle. I did it again on a cold engine with WOT And both my cylinders went up 10 psi to 145 and 125, which is still 20 psi difference from each other. So is a top end rebuild probably going to be my best option? Or possibly just buying a rebuilt engine from SES?
 
Your compression gauge is suspect because a perfect compression 951 is 130 psi and at 110 psi it is done.
Regardless of the actual number the 20 psi difference between cylinders tells us you have a bad cylinder and will let go pretty soon so at a minimum a new top end and oversize bore are mandatory.

On a higher hour 951 the crank and balancer typically do not survive a new top end.

Lots of horror stories here from SES so do your research first and make an educated decision.
 
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