1986 25hp wont start after a run

[nicknick]

My evinrude 1986 25hp starts fine , runs well but if I anchor up for an hour or so it will not start again. If it does it only runs unevenly until it is put into gear and cuts out as soon as revs are applied. Also the squeeze ball on the fuel line between tank and outboard is 'soft' and does not seem to draw petrol and harden during the attempt to start the engine.
Any ideas or suggestions..
Nick from England

 

[freddyray21]

Re: 1986 25hp wont start after a run

if the ball is getting soft it could be a fuel pump issue. When you first start it do you prime it by pumping the bulb? It should hold it's firmness from one run to another. I would check the fuel pump and replace the line and pump bulb.

 

[Silvertip]

Re: 1986 25hp wont start after a run

The primer bulb does not stay firm once an engine starts. Fuel is being drawn through it -- not pumped through it. It should not however be sucked flat. There is no need at this point to replace a fuel line and bulb at this stage. Especially since you have no idea whether you have good spark, dirty carbs, in need of a tune up. Throwing parts at a problem is not good diagnostic procedure and can get expensive. Disconnect the fuel line and use blund object to push in on the check ball on in the fuel connector. Then squeeze the bulb. If fuel squirts out that part of the system is ok. A compression check is cheap and easy to do. Low compression makes for a hard starting engine. If the carb has not recently been thoroughly cleaned and rebuilt with a new kit it's probably time for that. It sounds like the engine is being flooded when parked for awhile.

 

[freddyray21]

Re: 1986 25hp wont start after a run

maybe I misunderstood. If the primer bulb won't get hard by pumping it prior to the engine starting then I would replace it.

 

[tashasdaddy]

Re: 1986 25hp wont start after a run

is the arrow on the bulb pointing toward the engine?

 

[Texasmark]

Re: 1986 25hp wont start after a run

Ignition coils are notorious for getting hot and opening up. They will take you across the lake but won't bring you home. Happens time and again.

But your post said you have a problem if you let it sit. Are we to assume that if you ran as mentioned, shut her down and immediately or thereabouts tried to restart it would? If so it doesn't sound like a coil.

Mark

 

[Silvertip]

Re: 1986 25hp wont start after a run

If a primer bulb won't get firm, before I replaced it I would check the float level in the carbs. An inlet needle that's stuck open would allow fuel to pour into the engine and bulb would never get firm.

 

[freddyray21]

Re: 1986 25hp wont start after a run

I agree it would also make sense why it's hard to start after it sits for a little bit. The carb is loading up. When it does start it runs rough until he opens it up to clear the gas out of the flooded carb. Makes sense.

 

[h_lankford]

Re: 1986 25hp wont start after a run

I had a problem like that once. Would run fine for an hour, stop for lunch or whatever, then poor starting and running. By process of elimination, it always went away when I opened the tank cap.

Why? The cap vent was clogged, and after running for an hour, there was just enough vacuum in the tank to prevent good restart and running.

Just a possibility.

Please post your findings, whatever and whenever it may be. It is good for all of us readers and advisors (big and small) to have feedback.

 

[nicknick]

Re: 1986 25hp wont start after a run

thank you everyone for your advice.
I did replace the fuel line and bulb , the vent cap is always open during running but the problem persisted. I am unable to get down to the boat until next week but I will try out your suggestions etc and report back.
I use the boat on the River Thames estuary and its no place to break down on these dark winter evenings with the heavy shipping about. thanks again.

Nick from England