Help evinrude problem

[whoitd]

Hello, I have my uncle's 1973 evinerude 25hp s#25303 ae0001996.It has no throttle response and feels like it has a miss in engine. It backfire thru exhuast in 55 gal drum. I check compression cly 1 115psi and cly 2 115psi. I checked spark has 1\4in strong and blue in color. I checked the piont settings reset them to.020in. I notice that this little 2 stroke smokes in my opinion way too much than normal(mixing 50:1) and extreme amount of oily muk left in the 55 gal drum.I look up thru exhuast port and it is real milky white in color.Also cleaned carb out, something was blocking the high speed jet. Any suggestions what to do to get this running good again would great. Thanks, Jim

 

[MCM]

Re: Help evinrude problem

Hi, <br /><br />The backfire could be caused by a air/vacuum leak such as sucking air through a bad gasket (manifold, exhaust, etc.<br /><br />Running too lean could do this also.<br /><br />You might consider a carb rebuild as opposed to just cleaning it, its an inexpensive place to start.<br /><br />Mike

 

[steamboatwilly]

Re: Help evinrude problem

check the flywheel key

 

[whoitd]

Re: Help evinrude problem

Thanks guys for your replies. The carb was rebuilt last year with new kit, the foam from engine cover was what got sucked into carb which blocked high speed jet. I checked the flywheel key and is good and same with groove in the flywheel. I talked to my uncle tonite and he said that it was surging up and down (idle) then died . He couldnt get it to start after it stalled.

 

[Scotty's Fujiboat]

Re: Help evinrude problem

I think your point gap may be to small.I can't find what the gap is, but If I couldnt find the point gap, I would use a match book cover, that always got me close enough to get it running close to normal, but that is me! lol also, check for rust on your magnets on the flywheel and give them a good cleaning as well as the pick ups on your coils. A fine grit emery cloth usually takes the rust off without doing any damage. You should be using Champion plugs =UJ4J WITH A 0.030 GAP<br />Hope this info helps you a little<br />-Scotty-

 

[MCM]

Re: Help evinrude problem

Whoitd,<br /><br />Check out this old post, especialy Joe Reeves advice may be something here that can help<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=28;t=030676#000025 <br /><br />Good Luck,<br />Mike

 

[whoitd]

Re: Help evinrude problem

Scotty , the points set is .020 according to manual and stamped on the flywheel. They are new pionts and coil. I set them at .020. What is the best way of checking to see if the exhaust gasket is blown and would that make it have no power, smoke more than usual, and back fire. Any tell tale signs to check. <br /><br /><br />Mcm I'll check it out now , Thanks Guys

 

[steamboatwilly]

Re: Help evinrude problem

If it is backfiring ,that has to be something about the firing or time.(I think)

 

[MCM]

Re: Help evinrude problem

Whoitd<br /><br />Backfiring is a symptom of an air leak/gasket leak<br />among some other things<br /><br />If you've got water in a cylinder do to a gasket leak its gonna smoke in addition to running like garbage, if it runs at all<br /><br />The surging would also indicate an air/vacuum leak<br /><br />The milky color you described sounds like oil mixed w/water<br /><br />Mike

 

[whoitd]

Re: Help evinrude problem

MCM on the exhuast cover one side of the cover should be water cooled and other side of plate shoul not be right or wrong?

 

[Scotty's Fujiboat]

Re: Help evinrude problem

No, I don't know where to check for a blown exhaust gasket, but im thinking that really shouldnt make it lose all that much power if that was the case. As for the smoke, that may clear up once you get it running right and on the water. I have a 69 Johnson 20 HP that did the same thing. I rebuilt the carb and replaced a coil that was fried. I found that out by with the engine running, i pulled the plug wires one at a time then listened to the motor. one cylinder with it pulled off did nothing, when i pulled the other one, the motor died, so I replaced that coil and she fired right up, smoked a lot less and stopped backfiring. you can also check your timing plate (under the flywheel) to see if it moves freely. Im glad that your points are set corectly though.

 

[MCM]

Re: Help evinrude problem

Theorotically,<br /><br />Did you read the link I gave you earlier<br /><br />Several things can cause the problems your having, that link covers alot of them<br /><br />Mike

 

[Scotty's Fujiboat]

Re: Help evinrude problem

Also, check the carb bolts & make sure they are tight and make sure the choke mechanism is not sticking. Hoping that foam that got sucked in didnt get into your reed valves and got stuck there

 

[whoitd]

Re: Help evinrude problem

Thanks Scotty, I will try a balance test tommorrow.The coils look brand new. The timming plate does move freely.I also allready did most of what Joe Reeves said on Mcm post. The fuel pump is new, but when i pumpthe fuel primer when it is running it stalls and has hard time starting. I did put new plugs in it (correct ones) and i did get the surging idle fixed , but still no power. Thanks , Jim

 

[whoitd]

Re: Help evinrude problem

Mcm, I,m still reading it 505 replies lol

 

[MCM]

Re: Help evinrude problem

Yea, its a pretty big one, But like I said it covers alot ground,<br /><br />I really hope you can find something in there that'll help.<br /><br />Good Luck,<br />Mike

 

[whoitd]

Re: Help evinrude problem

Well guys still reading it . I will do a coil test tommorow , even tho they look new doesnt mean that one could be bad . I will try that tomorrow and let you guys know. Thanks for helping me, Jim

 

[Walker]

Re: Help evinrude problem

The backfire as you called it sounds like a lean sneeze to me. Slowly turn the idle mixture screw counter clockwise and I believe you'll see the sneezing stop and the idle rpms pick up.

 

[MCM]

Re: Help evinrude problem

Mentioned that one in my first post <br /><br />Mike

 

[whoitd]

Re: Help evinrude problem

Ok guys got it running good.<br />1. found the recirculaion vac hose was split under carb.<br />2. readjusted points (2nd time)<br />3. float was mis-adjusted<br />4. thermo stat was stuck<br />5. 2 wires under timer plate bad ( i repaired them)<br />I now have a good idle, no hard starting, good throttle response, alot less smoke, and the mukky white stuff stopped comming out of the exhaust. Will take out on test run on Sunday to see how it runs. Thanks guys will let you know what happens. Thanks agian, Jim