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Accelerator pump not working

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HI I'm a new member just signed up now. and I have a problem with my jetski and could use some help.

I have a 97 seadoo gts with the 717 engine and single carb and my accelerator pump isn't working.

A little history, I bought the jetski about 6 months ago its my first one ever. it sat unused for about 7 years because the carbon seal went out and the guy never got around to fixing it so I bought the jetski and replaced the carbon seal and all related parts and rebuilt the jetpump. the carb on the machine was broken and cracked almost in 2 so I bought a different carb off ebay that was posted as being for my machine but arrived with a tag saying removed from a GSX and it has a accelerator pump which my old carb didn't have. I rebuilt the ebay carb and pressure and pop off tested the carb and installed a new accelerator pump diaphragm and all was going good everything was perfect for about 1 month and I screwed up somehow and my jetski ingested a bolt down the carb throat while running WOT and did a bunch of engine damage and I had to replace the engine block with a low hour one on ebay, a rebuilt crankshaft from SBT, a new 159 degree rotary valve and good condition new rotary cover and all new engine seals but I reused my top end.

all is back together and working good with good power except its slow on the take off. when I go from idle to WOT it hesitates. basically like I floor it, and it stays at idle for about the count of 3 then it takes off like a rocket. turns out my accelerator pump is not squirting which is probably my whole problem I'm pretty sure.

the accelerator pump jet in the carb throat is clear, the hoses are new and clear. if I have the ski running and I manually push the diaphragm of the accelerator pump it doesn't squirt either so I'm pretty sure adjustment is not the problem, the hose after the pump leading to the jet is dry, no evidence of fuel, take off the line going from the carb to the accelerator pump and it has a good steady stream of fuel flowing out of it. so fuel is getting to the accelerator pump just not getting past it. should It have any real pressure coming out of that hose or does it just need flow? its basically flowing out like its gravity feeding out of the carb. is that normal or should it really be squirting out the hose before the accelerator pump?

as I stated before this is my first jetski so I wasn't very familiar with rotary valve engines until I rebuilt this one :thumbsup: mostly I'm trying to figure out if I should have real pressure coming out of the hose going to the accelerator pump or is just good flow good enough? I am not really familiar with how the accelerator pump should operate other than it should be squirting into the carb on first throttle but its not.

thanks in advance guys
 
If you are sure it's the accel pump I'd simply remove/bypass it and replace the jets with those from your old carb.
 
Yes im sure it's the accelerator pump but I had it working before the engine damage. Before the accelerator pump was working perfectly and immediate throttle response and everything.

The accelerator pump only stopped working sometime between the engine being out for 1 month for repairs, and when it was reinstalled and rebuilt engine again.

So Id like to get it working since I had it working already.

Maybe I didn't put the spring back in the right spot inside the pump or maybe it got clogged.

If I put the carb inlet and return hoses reversed would the accelerator pump stop working?
 
Disconnect the hoses going to the nozzles and move accel pump by hand. If fuel squirts out from the hoses then the nozzles are clogged.
 
There is a little check ball in the body of the accelerator pump that can get stuck. It allows fuel into the body of the pump and then closes to allow the fuel to be pushed out of the sprayer in the throat of the carb. It basically acts as a one way valve. I have had them get stuck so bad I had to replace the entire body.
 
mikidymac said:
There is a little check ball in the body of the accelerator pump that can get stuck. It allows fuel into the body of the pump and then closes to allow the fuel to be pushed out of the sprayer in the throat of the carb. It basically acts as a one way valve. I have had them get stuck so bad I had to replace the entire body.
Click to expand...

I don't remember seeing a ball valve when I installed a new diaphram in the accelerator pump. But that sounds like a good thing to check. Probably need to pull off the accelerator pump tonight after work and open it up
 
You won't actually see it. It is inside the casting fed by one of the holes and exits into the fitting that connects to the sprayer.
 
How do I tell which hose going to the carb is the inlet and outlet hose going to and from the gas tank? I took off the 2 hoses and one lots of fuel was coming out I'm assuming that's goes to the inlet of the carb, and I'm assuming the hose that almost nothing came out of was the return fuel line? is this correct?

if so I had my fuel lines backwards on the carb according to this site http://www.seadoosource.com/mikunitests.html which said the fuel inlet on the carb is the bottom fitting
 
Follow the lines. The return line will go directly to the tank. The ON line will go to the fuel filter/water separator then to the fuel valve, then 2 lines to the tank.
 
What would the symptoms be if for example: if my A pump was adjusted too tight like the diaphram plunger would be always pressed a Little even at idle? Tonight I should adjust the a pump adjustment a little looser then try it before I tear it apart
 
I have never touched the adjuster for the accelerator pump. IF it squirts fuel when pumping it it is working, if not then it has a blockage. That is about all I can tell you.
 
i think this might be the problem



i found it under the diaphram loosly floating around next to the spring thats inside the accelerator pump

i am pretty sure it was originally attached to the (new as of 4 months ago) accelerator pump diaphram off ebay. i am not sure why its on the accelerator pump other than to maybe help keep the spring inside centered on the diaphram
 
that washer was just resting over the top of the check valve hole on the accelerator pump.

and yes it seems the check valve is also NOT working. seems to be stuck and so far i havent gotten it unstuck yet. have tried soaking it in wd40, sprayed it with seafoam Deep Creep. blew it with compressed air all directions, next attempt will either be soak overnight in Xylene (similar to paint thinner) which is what i have left over from painting my Willys Jeep
 
The check ball is now unstuck. I already tried to air compressor blow gun and it didn't work

but then I tried my other blow gun that has a rubber tip and then it finally worked.

so now that I have the hard washer removed and reinstalled correctly that prevented the diaphragm from being pushed all the way and now that I have the check ball moving I am assuming all is good and will put the carb back together but I may not be able to reinstall the carb and verify for a couple days because we have some terrible wind and rain coming tomorrow

I will repost after all is reinstalled and working OR not working
 
carb is back together and on the jetski.

THE ACCELERATOR PUMP NOW WORKS AND NO MORE STUBLE

all seems fixed no issues, except when I was putting the back cover back on the carb the one screw seemed stripped and didn't feel like it really tightened that much
 
Nice work. You got lucky with the check ball. I have had to replace the entire cover before on one that just wouldn't move even after weeks of soaking.
 
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