1997 Mikuni Help

[JDusza]

I have a GSX Limited dated 27/05/97; serial C1A7000753; Rotax 979600.
The cylinders are flooding.
The on-line carburetor schematic does not quite match what's in the machine and the orientation of the schematic appears not to be how the Mukuni is mounted in the machine as it sits on the water. Argh!
So, where are the high speed and low speed jet adjusting screws? On the top side of the primary carburetor as it sits in the machine, on the water, there is an adjustment needle under a cap on the port side of the machine. on the starboard side there is what looks to be a plugged jet. Should this be an adjustment or is something broken off inside, perhaps?
Thanks.

 

[Dr Honda]

If you think that the carbs are not from the factory... please post a picture so we can see them.

 

[JDusza]

Not sure how to get you my picture. Can you tell me how or can I get your e-mail?
Thanks.

 

[JDusza]

Let's try this.
The carbs are from the factory.
Adjustment on left has cap. Which jet is this? I can remove this cap and make adjustments.
Adjustment on the right is blocked off. You can see this. Which jet is this one?
Any advice is appriciated.
J

 

[Dr Honda]

Yep... that is a factory carb.

The needle on the left (Top of the carb) is the high speed needle. The one to the right (bottom of the carbs) is for the Mid needle, but Seadoo doesn't use it. Your low speed needle is on the other side, toward the bottom of the carb.

Yes, you can take the cover off, but you should not need to make any big adjustments. If you do... then you need to take the carbs off, and clean them.

FYI... Those are only adjustment needles. The "Jets" are inside the carbs.

 

[JDusza]

Thank you very much! I understand! Now I know what I have been playing with !!!
These carbs will need to be taken off and gone through.

I have tried adjusting the high speed jet to no avail. At the time I thought I was working with the low speed. In fact, I had originally found this high speed jet virtually closed. Apparently, someone tried to lean this out before me.

The machine is getting choked up at start-up and cannot burn off the excess fuel at high speed. Smokes like you can't believe. I can shake liquid fuel off the plugs... If, by chance the fuel does burn off and the engine leans out, it is a very powerful and fast ride. After a while at high speed it stalls out...

This sort of makes sense now, flooding at start-up through warm-up and if the high speed jet was virtually closed, this may account for me being partially successful in burning off fuel and then stalling out....

Changing my thinking to believe the choke or low speed adjustments are whacked. Is there an easy-access way to adjust the low speed and choke?

And, definitely sounds like a carb cleaning / rebuild is in order.

Thank you so much!
Jim

p.s., for my own satisfaction: are the jets removable or machined/inserted in the carb casting? Never opened one of these before...

 

[Dr Honda]

Stock Jets: 97 GSX:

Main: 142.5
Pilot: 70
N/S: 1.5
Pop-off: 23-43 psi
Low: 1 turns out
High: MAG 0 turns; PTO 1/2 turns out.



That's your factory settings. If everything is clean, and working... it will run perfectly at those settings.

 

[JDusza]

Thank you.
What's the trick to getting to the low speed adjustment? I can just barely touch it with a single finger. Is there a tool to attach to the t-adjust?
J

 

[Dr Honda]

I just use a mirror, and reach under. (Sorry, no good tricks to tell you about)