Surging at WOT on a 1988 88hp Johnson

[nastyquedawg]

2 weeks ago I rebuilt the fuel pump on my motor. I took it out last Sunday and it ran fine other than the fact for about 1 sec the motor died down and ran fine the rest of the night. Took it out yesterday and towards the end of the 3 hour fishing trip, whenever I ran the boat at WOT the motor would peroiodically lose rpms. I decided to come home and call it a night. I checked the fuel pump and saw no leaks. Check the fuel line also. Are there any ideas on why this is happening? I dont think i rebuilt the fuel pump incorrectly, I assume fuel pumps work or dont work. Thanks in advance for any assistance that can be provided.

 

[TD_Maker]

Re: Surging at WOT on a 1988 88hp Johnson

I have some experience with the 88SPL Motor. I had one of these great engines on the back of my 17' Whaler. I also had a surging issue. Mine turned out to be dirt from the gas tank was clogging my in-line filter and I also had some gunk in the screen just inside of the fuel pump. Just a thought. I wish I had that old engine back on my McKee craft now.

 

[emdsapmgr]

Re: Surging at WOT on a 1988 88hp Johnson

Surging is often a result of insufficient fuel flow to the carbs. You can test that theory next time you go out. When it starts to surge, have your buddy constantly prime the fuel hose bulb. This will force extra fuel into the carb bowls. If the engine runs fine at WOT as long as you constantly prime that bulb, the engine is running out of fuel. That could be anything from a weak fuel pump to a clogged anti-siphon valve to a bad fuel pickup in the tank to a bad fuel hose bulb, etc.