1986 70hp Evinrude won't run now

[hila2006]

Well just replaced my prop that fell off, now she won't run at all. We bought the boat used 3 years ago, and it had sat for 3-4 years prior. We put a lot of work into her to get her up to normal, a lot of new parts, carpeting, pumps etc. But she always ran extremely well. Last year we had a fuel line crack at the filter inlet, so I replaced that and moved on in the season at the lake. About a month later she started to run odd, wouldn't start after running for a while, it would surge at running speed, almost like it was running out of gas. I replaced all the fuel lines at that point, I'm no mechanic, I've done plenty of my own repairs on cars, but I'm no outboard mechanic. I know I don't have all the fuel lines run exactly as they were, they are all hooked up to the right places, but not in the right sequence maybe. In other words there might be a small kink or 2. I tested the electric primer last year according to a repair guide I bought on here, and the primer was working fine. I always use a fuel stabilizer when I get gas. I just changed the plugs, didn't help. It won't start unless I spray a little carb cleaner into the side of the air cover, she'll fire right up and run at our dock with no problems. The second we try to take it out on the lake we have no power, just bogs. Now it won't start without the carb cleaner, I really could use some help before I call either the mobile mechanic or take it to a marina. After putting the new plugs in last night I tried to start it and nothing. I pulled the plugs and they were wet and smelled like fuel. I think that's it, so many thanks for any help, the boat is my only outlet for stress and I could use some stress relief for sure.

 

[hila2006]

Re: 1986 70hp Evinrude won't run now

I forgot to mention that I also found a red wire that the insulation had cracked and fallen off most it's length. It was on the wiring block next to the 3 coils, with a couple yellow wires etc. I placed some 600v shrink sleeve over and sealed it back up. I'm not sure if this has caused any problems that I'm now having. Thanks.

 

[eavega]

Re: 1986 70hp Evinrude won't run now

Red wire in the wiring block (not the power pack) is the rectifier. You probably need to check the rectifier for proper function, but that shouldn't stop your motor from working (I think). Before doing the rectifier check, though, do your basic checks for compression and spark. We can assume you are getting some fuel since your plugs are wet, so if it were my motor, my first guess would be spark if it has good compression.

Rgds

 

[hila2006]

Re: 1986 70hp Evinrude won't run now

Thanks Eric, my only dumb question I guess would be, why does it start if I spray carb cleaner into the side of the air cover? and it will idle no problem once I get it started?

 

[BonairII]

Re: 1986 70hp Evinrude won't run now

why does it start if I spray carb cleaner into the side of the air cover?

Don't start your motor with carb cleaner or starter fluid....bad for the motor cause it washes cylinders of oil. Make up a spray bottle of premix gas and use that as your "starter fluid".

 

[mikjas2]

Re: 1986 70hp Evinrude won't run now

No expert by ant means but sounds like fuel pump.Mine will start and idle great but will not get up and go unless someone pumps the ball.Turned out to be pump anyways hope it helps

 

[hila2006]

Re: 1986 70hp Evinrude won't run now

Yeah I know the dangers of carb cleaner for starting purposes, but in the situation I'm doing, I'm only using a quick spurt in the tiny hole in the side of the carb cover, so I don't have to keep unscrewing the carb cover. But it still doesn't answer the question "why does it start if I spray carb cleaner into the side of the air cover?" I'm just wondering if I'm wasting time looking at spark, if it will start that way. My father-in-law is a small engine mechanic,lawn mowers etc. He said to drain my gas completely and start fresh, he thinks we've got a tank full of crappy gas from ethanol, even though we use Stabil. So we're going to fire it up tonight and run it at our dock to try and burn up as much old gas as possible, then drain the rest. I'm actually thinking of hooking our fuel line up to a small gas can and trying it that way also. Any other ideas or suggestions will be greatly appreciated.

 

[BonairII]

Re: 1986 70hp Evinrude won't run now

I'm actually thinking of hooking our fuel line up to a small gas can and trying it that way also.

that's exactly what you should do. The portable tank(with fresh fuel) will rule in/out the bad gas theory.

 

[eavega]

Re: 1986 70hp Evinrude won't run now

Ya know, my bad. I misread your original post and thought you said now it won't start with the carb cleaner. I was pointing towards weak spark becoming no spark. Problem will probably be fuel, but in any case, it takes 10 min to test spark and compression, so I will usually at least verify that those items are in working order before getting more involved. Low hanging fruit, KISS, all that good stuff. Definitely need to verify you are seeing the same symptoms when using good fuel.

Rgds

 

[hila2006]

Re: 1986 70hp Evinrude won't run now

No prob. Eric, was just confused by your answer that's all. Thanks for all the input everybody, we really need our boat going. We live on a nice small lake, good bass fishing, swimming etc. We just moved here in June and the boat was running awesome, so I'll post results when I can.

 

[LongLine]

Re: 1986 70hp Evinrude won't run now

Sounds to me like you better check that spark and specifically the resistance of the coils.. Very possible cranking speed isn't getting up to an RPM that all the coils like. Starter fluid being more flammable takes less energy to ignite & 2 cylinders would turn that engine over at higher rpm.