No power in water hard to start , fine on trailer .

[anhel07]

Hi guys first of all i am a newbie from Greece and i am sorry for my english. I have a 2002 sea doo 717 .

Ski runs fine on trailer, idles smooth and revs up and down without a problem. Put it in the water, and it's hard to start. If you get it started, it will only idle. Engine does not rev any higher, RPMs stay around 1500 even with the throttle fully squeezed. If you hold it at WOT for a few seconds the engine bogs and dies. Pull it out of the water, and it starts and revs fine again.

Sometimes you can get it to kick and start running at full speed 35-40 mph, but as soon as you let go of WOT it will die and won't start again. Plugs seem to have too much fuel ( and oil mix ?)on them when pulled out, seems like possibly running too rich. Hi and low speed mix screws are at stock settings. I have change allready the piston with new 82.5 mm , bored cylinders , rebuilt the crankschaft ( all seals , bearings ) and carb rebuilt but except needles . I mess the rotary valve clearance ( 0.30 mm ) and i think the rotary valve is timing correct .

If you have any ideas please respont !!!

 

[LouDoo]

Well it sounds like low compression but as I read your post, with the engine work you have done, the ski shouldn't have low compression, but just to eliminate the possibility, get a compression reading on both cylinders. To check the compression, remove both spark plugs, ground the spark plug leads, check on a cold engine, throttle open.

The other thing that comes to mind is a bad voltage regulator/rectifier, to check just disconnect the red wire on the rectifier, if the problem clears up replace the rectifier.

Lou

 

[AdamXP800]

It does sound like the classic low compression. I would get a guage to double check even though you just did an overhaul.

 

[Dr Honda]

x3....



Even with new parts... you could have cracked a ring during the assembly.


If the compression is good... pull the intake, and check the RV timing. It's one or the other.

 

[anhel07]

x3....



Even with new parts... you could have cracked a ring during the assembly.


If the compression is good... pull the intake, and check the RV timing. It's one or the other.

Thanks you guys . The compression is very good 145 on the front and 140 on the other . Can it be the rectifier?

 

[anhel07]

or the carbs-oil pump? whats with the water box can this make a problem?

 

[LouDoo]

The reason I said to check the rectifier is because when mine went bad the symptoms were very much like yours. Compression was good, the ski ran well on the trailer, but in the water it felt like it was running on one cylinder. Also it's very easy to diagnose, so try that first.

If that doesn't fix the ski then check the rotary valve timing. Here's a video.

http://www.youtube.com/watch?v=ULL5gfQs_UA

Lou

 

[anhel07]

The reason I said to check the rectifier is because when mine went bad the symptoms were very much like yours. Compression was good, the ski ran well on the trailer, but in the water it felt like it was running on one cylinder. Also it's very easy to diagnose, so try that first.

If that doesn't fix the ski then check the rotary valve timing. Here's a video.

http://www.youtube.com/watch?v=ULL5gfQs_UA

Lou

Ok lou thanks very much . I try today and let you now .

 

[anhel07]

Hi guys i am back from holidays .We found the problem that was the rotary gear seal and replaced it . But now i have a new problem.Starts fine only without the water box connected with the exhaust and when the starts is backfiring( fuel spitting without flame) badly through the carb.
Any ideas?

 

[Strizzo]

backfiring out the carb could be an issue with the rotary valve timing. did you take the rotary valve off when you were replacing the cover seal? the timing needs to be set within spec in order to run correctly. backfiring can also be caused by running lean but this sounds timing related, either rotary valve, or ignition (could be caused by a bad voltage regulator/rectifier).

 

[LouDoo]

Rotary valve timing.

Lou

 

[anhel07]

no i am sure the rotary valve timing is correct !!! anyway i will trie in other position and see what happens .and that with the exhaust-water box ?

 

[slotcsx]

Is your idle speed correct? Had a problem with keeping mine running because the out of water idle was set at 1500 rpm and was supposed to be set to 3000.In water was supposed to be 1500.