1987 Evinrude 175 HP outboard surging

[rolander]

The engine surges at wide open throttle. It gains power then dies off, feels just like it's picking up a cylinder or getting a burst of fuel. Or if you were at wide open throttle, pull back then lay into the throttle again. Just like a surging.

I have had this problem for some time already. I don't think it is fuel related as I have been through everything. I have cleaned carbs twice, reed valves are fine, fuel bubble is good. I also tried without the fuel bubble. No change. Fuel filter is clear and also even tried a different fuel tank. No change.

I have tried a couple of different control boxes thinking maybe something in the wiring was bad. No change. I also have tried new plugs and swapping all the coil packs around with a known good one also no change.

What do you guys think? I have not tried plug wires yet. Anything else I could be missing?

Thanks

 

[dchris103]

Re: 1987 Evinrude 175 HP outboard surging

I am having the same issue with my 1993 johnson 200. I replaced my plug wires. I have had the carbs rebuilt, the powerpack replaced, and the stater replaced. I changed the fuel filter and installed a fuel/water seperator and NO change. My next avenue is to replace all my fuel lines.

 

[rolander]

Re: 1987 Evinrude 175 HP outboard surging

Well keep me in the loop if you find your problem and I will do the same. I even took the check valve out of my gas tank to eliminate that as a problem too.

 

[dchris103]

Re: 1987 Evinrude 175 HP outboard surging

Well, in the process of replacing my fuel line from the tank to the splash pan, I discovered a fuel-water seperator under the deck. I decided to bypass the old one and used the "new and improved" or ethanol resistant fuel line and no change after running it this morning. So to the pros it goes. I will keep you posted on what the mechanic tells me, rolander. Good luck.

 

[emdsapmgr]

Re: 1987 Evinrude 175 HP outboard surging

Have someone constantly prime the fuel hose bulb while you are running full throttle. This will force extra fuel into the carb bowls. If the engine runs fine at top end, you may have a weak fuel pump. A weak fuel pump will not supply enough fuel to sustain high rpm's. Once the bowl drains of fuel, the engine will slow, till the pump can replace the fuel in the carb bowls-then the engine will take off again.

 

[mrbarrettbryan]

Re: 1987 Evinrude 175 HP outboard surging

I am having the same problem with my 1985 Evinrude 115.. i have rebuilt both the carbs twice, replaced the fuel lines from the engine cover to the fuel pump and from there to each carb. I have double checked each highend fuel jet and cleaned out the fuel pump screen. I have also added a filter on the main fuel line. the only thing i have not done is replace the whole line or messed with the gas tank.. Any ideas? At this point I feel strongly that it could be the fuel pump or something in the gas tank..?

 

[dchris103]

Re: 1987 Evinrude 175 HP outboard surging

Well, I picked up my boat from the shop on saturday. Running great. The mechanic rebuilt the fuel pump and replaced fuel lines from the splash pan to the fuel pump. He said the diaphragm was twisted and the springs were stretched. I hope this helps anyone applicable. Good luck.

 

[mrbarrettbryan]

Re: 1987 Evinrude 175 HP outboard surging

Thanks for the info, i took the fuel pump apart and checked everything out and it all seemed to be fine:S When yours was bogging out before did you try pumping the primer ball and what happened if you did. I was told that if it was your fuel pump that when you did that it would give it the gas needed and take off but mine doesn't affect it when i pump the ball.. Any ideas??

 

[emdsapmgr]

Re: 1987 Evinrude 175 HP outboard surging

mrbarrett, you may want to start your own thread to address your problem.

 

[mrbarrettbryan]

Re: 1987 Evinrude 175 HP outboard surging

Its not allowing me to for some reason!:S

 

[rolander]

Re: 1987 Evinrude 175 HP outboard surging

We tried pumping the ball but didn't change it either. Mine is so erratic. That's why I am thinking electrical. It just doesn't spit or sputter like it's running out of fuel.

Seems there are a few of these motors out there with similar problems

 

[emdsapmgr]

Re: 1987 Evinrude 175 HP outboard surging

It's easy to check for spark when the engine starts to act up. Take an inductive timing light with you. When you think it's missing, put the timing light lead on all 6 plug wires and look at the flashes from the gun. It will show misfires, no fires and weak firing.

 

[rolander]

Re: 1987 Evinrude 175 HP outboard surging

Again thanks for the tip with the timing light. I did use one over the weekend and found irratic spark on two cylinders, the port side top and bottom cylinders. plug wire? Coil? Spark plugs?