Well that didn't work / Carb rebuild.

[finatic@aol.com]

I have a 1997 Seadoo with twin 717 motors. I bought it barely running. I bought two quality carb rebuild kits (at least based on the price I paid) that also came with new needle and seat. I have a manual and I took great pride in tearing them down, cleaning with carb cleaner and compressed air. When reassembling I found the kit had some extra parts. I say this based on the stuff that came out of the carbs at disassembly and the exploded view in the service manual. Those extra parts are a gasket that looks a lot like that key hole shaped o ring and an extra black rubber diaphragm that looks like the only differance is a smaller opening next to where the filter is. I used the original spring for the needle and seat as I understand that is what sets the pop off preasure and I don't have the tools to verify that. When I put the carbs back on they both do the same thing. They started right up and idle good at about 3000 rpm. When I throttle up you can hear the butterfly open and an increase in air but no increase in rpm. Nothing at all even at wide open position.. One thing I thought was odd is that the high speed adjustment screw was turned in all the way on one of them and the other was opened about 3/4 turn. To me it seams like maybe there is no fuel to go through the high speed jet. Has anyone ever run into this?

Thanks
Mike

 

[DanSquires]

Were you sure to have the lever in the forward position?

 

[finatic@aol.com]

Throttle lever? Yes from idle when I push the lever forward you can hear the increase in air it just doesn't gain any rpm.

 

[DanSquires]

no, the gear selector.. R N F..
engine wont accelerate if the lever is in N..

 

[finatic@aol.com]

I did not know that. Just out of curiosity what controls that?

 

[jts32]

The motors will rev in neutral, but will quickly hit the limiter out of water. Are you sure the throttle cables are actually working properly, actually seeing the carbs open up? Have to double check the manual, but high speed screws are normally closed all the way.

 

[DanSquires]

The motors will rev in neutral, but will quickly hit the limiter out of water. Are you sure the throttle cables are actually working properly, actually seeing the carbs open up? Have to double check the manual, but high speed screws are normally closed all the way.

Boats have a neutral safety switch and will only rev to 3500 - 4k max when the lever is in neutral.

 

[jts32]

Boats have a neutral safety switch and will only rev to 3500 - 4k max when the lever is in neutral.

I have two '96 Challengers and a '98 Sportster 1800. All three boats will rev past 4k rpm with a quick blast of the throttle, so unless they changed something in '97, his Speedster should do the same

 

[wfo speedracer]

I have two '96 Challengers and a '98 Sportster 1800. All three boats will rev past 4k rpm with a quick blast of the throttle, so unless they changed something in '97, his Speedster should do the same

Dan is correct, rev limited at 3500 unless it is in forward or reverse, I have owned and worked on many of these boats.

 

[jts32]

https://www.dropbox.com/s/xbho1gfzicbonrr/VID_20171205_115344970.mp4?dl=0
All 3 of my boats do the same thing. They hit the limiter, but will continue to rev past 3500rpm on a quick throttle blast like the video shows

 

[jhjesse]

https://www.dropbox.com/s/xbho1gfzicbonrr/VID_20171205_115344970.mp4?dl=0
All 3 of my boats do the same thing. They hit the limiter, but will continue to rev past 3500rpm on a quick throttle blast like the video shows

Sounds like the neutral safety switch has been neutralized...get it haha. That was bad, I know.
To the OP, try starting the engines then put the shifter in forward and rev. Should rev past 3500rpms. If not then you still have carb problems.

 

[finatic@aol.com]

Don't I feel like the idiot. I went home and cranked each motor. Moved the shifter forward and there are my revs. It seems everything is working as designed. I did have one interesting thing. The port motor idles fine in neutral. When I move the shifter into gear it revs up without moving the throttle. . Pull it back into neutral and it idles down. As I recall when I rebuilt that card I found the high speed needle jet turned out 3/4 of a turn and that's where I set it when I rebuilt it. I'm wondering if that is the source of the high RPMs. It could also be the idle screw turned in to far. Anyway this weekend I'm gonna take the air boxes back off warm up the engines and see if I can fine tune all these settings.

 

[DanSquires]

Don't I feel like the idiot. I went home and cranked each motor. Moved the shifter forward and there are my revs. It seems everything is working as designed. I did have one interesting thing. The port motor idles fine in neutral. When I move the shifter into gear it revs up without moving the throttle. . Pull it back into neutral and it idles down. As I recall when I rebuilt that card I found the high speed needle jet turned out 3/4 of a turn and that's where I set it when I rebuilt it. I'm wondering if that is the source of the high RPMs. It could also be the idle screw turned in to far. Anyway this weekend I'm gonna take the air boxes back off warm up the engines and see if I can fine tune all these settings.

Dont feel like an idiot, I forget about that constantly.. then forget that it has to be in neutral to start..
Highs should be all the way in, but for the issue you're having, I'd suspect your idle screw is set too high, or you need to do a little adjustment to your cable..

 

[jhjesse]

Some please correct me if I am wrong. I am working from memory.
Highs - 0
Lows - 1 3/4 out
Idle - 3000rpms out of water 1500rpms in the water.

If you did your carbs right these settings will be very close.

 

[finatic@aol.com]

I set the carbs based on the settings that were suggested here and set the two motors at 2500 RPM out of the water. The two motors purr like a kitten. Will 2500 RPM be a little low once I drop it in the water?

 

[mikidymac]

It will probably be a little low but the best way to find out would be to drop it in the water.