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Help! Unusual evinrude 2.5

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Mcmattwich

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So I bought an evinrude 2.5 a while back, recently restored 1988 model. It has begun to stall out when heated up. I read online that the adjustable knob on the front is for cold starts (in florida, so n/a), and the one on the left is just a choke/gas turnoff. Taking off the cover, I cannot find where or how to adjust the idle.

Hoping to replace soon, because the lack of grip throttle drives me insane, but until then, and so I can sell it, how do I tune this thing right?
 
Impeller no, spark and compression are a go, it runs well until it heats up, I tested it early (5 am, sorry neighbors, had to know) and it runs for twice as long when it's cool out, as opposed to three digit temps
 
Mcmattwich said:
So I bought an evinrude 2.5 a while back, recently restored 1988 model. It has begun to stall out when heated up. I read online that the adjustable knob on the front is for cold starts (in florida, so n/a), and the one on the left is just a choke/gas turnoff. Taking off the cover, I cannot find where or how to adjust the idle.

Hoping to replace soon, because the lack of grip throttle drives me insane, but until then, and so I can sell it, how do I tune this thing right?
Click to expand...

The knob is the slow speed mixture adjustment. Pull the knob off to access the needle . When set correctly refit the knob in the centre of its range of movement. It should then not need to be fiddled with although it can help to enrich the mix a bit with warm starts that do not need the choke or by weakening the mixture during cold starts using the choke to make it less urgent to push the choke control back in. Both of these tricks you learn by experimentation and experience.

Probably best to clean the carb thoroughly first then adjust adjust the slow running mixture while the engine is idling as slowly as possible ( adjust the revs up again to normal idle speed after)

If Joe Reeves is around he will post his instructions for adjusting carb needles.

I doubt very much if slow speed adjustment is the cause of your problem
 
Thank you very much, so in saying that its probably not the slow speed adjustment, you are saying it is not the position of the knob itself correct? And adjusting the needle will actually adjust what I may need to in the carb? I was at work on break earlier, and in my rush I did forget; it's my understanding from research that this model was supposed to be re stickered or something, a sort of recall I guess, to indicate the Initial recommendation of 100 to 1 ratio should be 50 to one. The lady I bought it from said she had had it rebuilt by a shop class. So when I got it, I didnt know about the change, and ran 100 to one for a bit (it sounded odd, but it's only my second engine, and first 2 stroke) and presumably a student body wouldn't have known either, and adjusted it to what was labelled on the engine (because it ran like a CHAMP for a while). In essence, would adjusting this needle be what one would do to set it to run twice as oil-rich of a fuel?

I'm really hoping to get it worked out, it's also my understanding that this engine has a bit of kick for its size, because there not usually two pistons? My terminology may be wrong
 
Yes you are right. when this one was made OMC had gone over to 100:1 fuel mixtures ( From 1985 ) but very soon after yours was made they realised that 100;1 was a mistake and switched them all back to 50:1.

I don't think the change will affect the needle setting by a detectable amount. I have never heard any suggestion that it will. It may be doubling the amount of oil but it is only changing the amount of gasoline in the mixture by 1%, from 99% to 98%. Changes in atmospheric pressure will probably have more effect!
 
That makes sense, hadnt thought of it like that. You suggested the impeller, is there something that would make it shut down if it ran hot? It has given me problems on a few days, so I figured that If I were overheating my head would be toast by now
 
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