'74 15hp evinrude, again!

[johnnybahama]

I have done everything I can think of except a fuel pump and that's on the way. Good ignition and timing . Good compression. Rebuilt carb and the thing bogs at midrange. All I can think of is the fuel pump diaphram is leaking dumping fuel ito the crankcase. Alot of smoke in the exhaust. Never been in this spot before. Any ideas? Thanks

 

[AlTn]

Re: '74 15hp evinrude, again!

when you have the fuel pump off the engine, can you pump the primer bulb and fuel comes from the pulse hole on the back of the pump?.< some pumps you need to insert the mounting screws with nuts on the back to hold the pump together before you do this >.... was the carb float level parallel with the carb body when inverted?...carb reassembled, could you blow air into the inlet nipple with the carb right side up, but could not when the carb was inverted?

 

[OptsyEagle]

Re: '74 15hp evinrude, again!

You probably shouldn't start a new thread when you are still dealing with the same problem. You will end up answering the same questions and going over again all the things that have not helped.

In any event, in your previous thread you mentioned that the carburetor did not have a needle bushing and hence you put one in. This seems odd to me for the following reasons. Those needle bushings are not exactly easy to get out. It is unlikely that they would fall outontheir own and if a person went to the trouble of taking one out, I would find it odd that they would not put another one back in. Perhaps they forgot. In any event, they are almost impossible to see when looking inside the jet because their color blends in and you always have difficulting getting any light in there.

My point is, if your carb did have a needle bushing inside it and you now put in another, I am quite sure you would experience some form of operational problem. I can't tell you what they would be but it might be the one you are having. So with that said, are you absolutely sure you do not currently have two slow speed needle bushings inside your carb.

 

[johnnybahama]

Re: '74 15hp evinrude, again!

No there wasn't an exsisting needle bearing present. The needle seats perfectly in the orfice. Took out the one I put in and inspected it with a flashlight and pick. Before installing the new bearing I screwed the needle all the way in until seated, then installed the new bearing and again seated the needle, same position in orfice.

 

[johnnybahama]

Re: '74 15hp evinrude, again!

I've found that when the RPM picks up #2 Stops firing? Checking the timing and all was good, then I turned it up and that's when I found the problem. Ideas? It picks right back up when RPM comes down.

 

[johnnybahama]

Re: '74 15hp evinrude, again!

Also at idle it will run on #1 alone , but not on #2 alone.

 

[johnnybahama]

Re: '74 15hp evinrude, again!

Swap coils , same.

 

[sutor623]

Re: '74 15hp evinrude, again!

And I assume that you have tried swapping spark plugs also?

 

[AlTn]

Re: '74 15hp evinrude, again!

look at a thread currently on page 7 dated Nov. 25th by 69 Alumacraft titled ..1976 25 hp Points question...read the thread in its entirity...you'll need to use an adjustable spark gap checker in tracing this down...

 

[johnnybahama]

Re: '74 15hp evinrude, again!

Plugs are new. I'm going for the condenser.

 

[Pontoon24]

Re: '74 15hp evinrude, again!

Have you tried running it in the dark to look for spark jumping from a plug wire? Maybe a bad wire on plug #2

 

[johnnybahama]

Re: '74 15hp evinrude, again!

Swapped condensers, same. Swapped points, same. Swapped plugs, same. Decarbed. Wires pulled free of any contact. Checked spark on my Stevens spack checker good on both.

 

[johnnybahama]

Re: '74 15hp evinrude, again!

Going to swap wires at the points see if it follows them.

 

[johnnybahama]

Re: '74 15hp evinrude, again!

Did it all then I flipped the charging coil and everthing is great. wires up rather than down made the difference

 

[AlTn]

Re: '74 15hp evinrude, again!

good deal

 

[johnnybahama]

Re: '74 15hp evinrude, again!

The motor was back on the lake today and performed great, I was told. The only problem was it would not start without a shot of starting fluid, even when warmed up. My friend is 87 though. The only thing I did differently was put the next hotter plug in it, as he likes to troll.
I dialed the low speed down to a sneeze then fattened it up a half turn. In the past he always used starting fluid. I have heard of diesels becoming addicted to starter fluid, but a little two stroke? I do not want to drive a hour and a half just to fidget with it anymore. Any suggestions?

 

[kfa4303]

Re: '74 15hp evinrude, again!

Hi Johnny. Starter fluid actually strips internals of these old 2 stroke engines of their oil/lubrication. I would avoid using it, if at all possible. Is he choking the motor and priming the bulb before he starts it? That may help some too. While he really shouldn't have to spray anything in the carb, if he does need to, I would just tell him to keep a little spray bottle of premixed fuel. It should have the same effect without damaging the motor. Btw I'm right down the road in Tallahassee.