Welcome! Need support, you got it. Or share you ideas and experiences.
99 Evinrude 9.9 starves of gas. Last year my 9.9 / 4 stroke would start to sputter for gas- pumping the bulb would bring it back to life, only to stall 20sec or 1-2 min. later, depending on speed. Repair shop couldn't find anything. This year same problem, different repair shop said float was Â¾" off (?), replaced plug and ignition box. They said it wouldn't start, or ran really rough- I never had that problem. Bulb does not go totally 'soft', 1 or 2 slight squeezes is all it takes to bring the motor back. I have had it on 2 tanks, and 4 complete gas lines, and even hosed it right into the filter, bypassing the connection. Same problem- starts great- runs great- then starts to sputter- pump the bulb, (about 1/8 to Â¼ compression) brings the motor back t
Sorry to hear that you've already paid someone to look at it and the problem still exists - and you've inherited new ones too!
You said that the shops you took it to replaced the igintion box and the new problem started - well, hopefully you can have them resolve that issue by replacing the equipment that they put in... sounds like a bad box... wouldn't be the first time... this could affect your timing and ignition to the cylinders - which would definitely make the motor run rough.
As for the fuel starvation issue, we can eliminate all outside factors such as fuel lines and tanks because you've gone through the process already here and I commend you for that patience!
You mentioned that the motor would run in forward if you squeezed the fuel bulb. This could point to a few causes. One could be the fuel pump, another could be a carb setting. One question I have for you is - how well did the motor run in idle?
Compression - I believe this motor's fuel pump runs off of the compression generated from one of the cylinders... if compression is off on that cylinder then the fuel pump has problems. Check for leaks there as well.
Did the shop rebuild/clean the carbs? You mentioned a resizing of the float, but the symptoms still point to a stuck or gummed up float needle. Settings on the carb could be too rich/lean as well that could contribute to the stalling. A good way of assessing this is to take off the spark plus and check the condition for fouling, or too clean or burnt... By pumping the fuel bulb you may be temporarily fixinf the issue by changing the fuel flow, thus changing the fule mixture at the carb...
One last thing I would do is check for bad grounds. A good way to test this is to run the motor with the cover off late at night (in the dark) to check for any arcing (flashes). If you see this check to see if that particular wire is damaged.
Hope this helps in some way...
Andrew- Just about been through all that- What it took was for me to take it into the dealer, with my tank, and show their so-called "master OMC mechanic". He's the one that worked on it before....well he finally say it, (I had to show him in their tank)- and put a gage on the fule line and you could see the pressure drop- repump the bulb, and it would come back up- for a while. There gonna replace the pump. They tried to get me to cover the $25 ded. on my extended warrenty, but after the first go round- no way
we'll see what we get next.....
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