'97 90hp evinrude spl problem after decarb

[dwtata]

I recently did a decarb of my 1997 90hp evinrude spl. I followed the procedure listed in the FAQ here http://forums.iboats.com/showthread.php?t=158076. I did this with the muffs on in my driveway. After the decarb I replaced the plugs.

I then had the boat out last weekend and it ran great for probably a total of 1 hour of run time. I then tried to start the motor and it would not run below 1500 rpms. When it was running it was spitting and shaking and there was almost a thumping noise coming from the engine. I could start the engine with it reved, but as i would lower the rev it would stall immediately. Also, while i had it reved around 1500 rpm if i quickly pushed the key in for the choke the engine would rev up to around 4000 rpm then drop quickly. Not sure what i did or even if these topics are related.

I know its next to impossible to diagnose a problem from this description but the mechanic can't look at if for 3 weeks so any suggestions would be greatly appreciated.

 

[Big flop]

Re: '97 90hp evinrude spl problem after decarb

When the choke helps that much my first thought is
it sounds like it is running out of gas.
Dose pumping primer bulb make any difference?
Make sure there is gas in float bowls & no water
In the fuel system.

 

[dwtata]

Re: '97 90hp evinrude spl problem after decarb

From my inspection when we were on the water, there was plenty of gas. I checked the fuel filter it was clean and full of fuel. When I went to pump the primer bulb it was relatively hard and it did not make any difference. Im not sure how to check if there is gas in the float bowls?

There shouldn't be water in the fuel, i always add stabil marine formula for ethanol treatment. Over the winter we added stabilizer to the fuel and most of the winter fuel has probably been burned up. 18 gal tank and we have put over 10 gal in each time at two differnt fill ups.