1997 Speedster port engine Acceleration problem

[dgbehrends]

Thanks in advance for any advice.
1997 Sea-Doo Speedster. Twin Rotax engines. Planes fine once I get it up on plane.

Problem: Port engine will die if I try to accelerate rapidly with skier behind me. The problem isn't as much of an issue with no load behind me. In order to get the skier up I have to slowly creep the RPMs up to 3500 or so and then when I believe the engine is engaged can slam it and off we go. If I slam it from idle it will die. No issues with the starboard engine. New plugs greatly help, which is why I change them at the beginning of each season.

Another issue is that in order to keep the same RPMs on both engines the port throttle needs to be about an inch in front of the starboard. This came about after my dealer rebuilt the port engine in 2002 and after a few tries could not get the throttles aligned. They no longer sell Seadoo jet boats so won't work on it anymore. The throttle separation has never been much of an issue over the last ten years, but the port engine dieing is gradually getting worse and worse and it's time to get it fixed.

The boat runs great except for the problem I mentioned above. Both engines idle fine and she runs around 55 on the dream-o-meter WOT. (50 on the GPS).

My guess is that the mixture screw is set wrong or the throttle cables need to be adjusted.

What are your thoughts?

 

[Dr Honda]

Sounds like the carbs need cleaned, and the fuel system needs serviced on that side. You could also have an air leak in the fuel select valve, or water separator.

But... as with any issue like this... get a compression reading for us.

As far as the throttles not being in sync... we can't address that until the boat is running right. But, they are rarely together.

 

[dgbehrends]

Sounds like the carbs need cleaned, and the fuel system needs serviced on that side. You could also have an air leak in the fuel select valve, or water separator.

But... as with any issue like this... get a compression reading for us.

As far as the throttles not being in sync... we can't address that until the boat is running right. But, they are rarely together.

Thanks for the info. Unless the problem gets much worse, I probably won't address this until end of the boating season, which for me is late September. I plan on having a different dealer take a look at the problem. I'll discuss the possibilities you listed above and will have the compression test done as well.
-Derick

 

[khriss]

My 97 1800 had the same issue until today. I thought it would be the filters in the carbs, but found it to be a very old, non-flexible fuel pump diaphragm (the clear part) installed a new pump and assorted gaskets and o-rings, and it is as it should be.
However, my throttles do not line up still.
It took me about 3 hours, leaning over the bench, sometimes with my feet in the air. I should have gotten out the air ratchet, it would shave about an hour off the job.

BTW, be careful about running it this way (not fixing the issue) as you could lean out the motor. Lean and heat are the death of 2 strokes.

 

[dgbehrends]

My 97 1800 had the same issue until today. I thought it would be the filters in the carbs, but found it to be a very old, non-flexible fuel pump diaphragm (the clear part) installed a new pump and assorted gaskets and o-rings, and it is as it should be.
However, my throttles do not line up still.
It took me about 3 hours, leaning over the bench, sometimes with my feet in the air. I should have gotten out the air ratchet, it would shave about an hour off the job.

BTW, be careful about running it this way (not fixing the issue) as you could lean out the motor. Lean and heat are the death of 2 strokes.

Thanks for sharing that information! I've spent a lot of time upside down in my engine for other reasons so I'm not sure if I'm going to tackle this one or hand over my arm and leg so the dealer can do it.

 

[dgbehrends]

I found a dealer in Red Wing, MN that is going to do the carb rebuild for a reasonable price. Spoke to the mechanic there and he seemed really experienced and was very nice to talk to. I found out that my boat has a loose motor mount, (which I knew about but had forgotten/was neglecting ... not smart). I'm going to get the carbs cleaned and motor mount fixed and the carbs tuned with a water test.

Two other issues were discussed.
1) I've had the scupper valve rubber stoppered on both ends for about 6 years. Is there a replacement kit that I can buy and and install? If so where may I find it.
*Edit* It looks like there are scupper valves to be purchased all over the place. I searched through the forums and most of the links people posted know longer worked at the vendor website. If someone wants to share a more recent link of a scupper they successfully installed that would be cool.

2) The dealer said my fuel sending unit was working fine but my fuel gauge was bad, and that the part was discontinued and they would not be able to get a new one. They said I should do a search and could probably find one on ebay or elsewhere on the internet. Does anyone have a link to the part number or a place I can purchase one?
*Edit* I think this is the correct part number 278000496. Found a new one for $180 and used ones on ebay for $50ish. I'm going to ask the dealer how they tested the baffle. I'll probably pull the baffle out to make sure I don't have a fuse or float/missing magnet problem.


Thanks in advance.
-Derick