Introduction / 83 evinenrude 25hp question

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Michaeldinpc

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Hey there! Just signed up, been lurking for a while when tinkering with my 71 18hp twinfast. Site helped a lot than but I'm having a hard time locating info on my current project. e25rcte. 1983, 25hp, pull start, short shaft, Evinrude. First thing I did was take a look at the plugs, there was moisture.... Placed a paper towel in front of the plug holes and pull started once, there was rust dust in front of both holes, mostly fron the top. I sprayed some WD40 pulled it a couple times to saturate the entire cylinder, sprayed some more turned the motor so it would settle to the piston and rings and let it set. I pulled and cleaned the carb while I let it soak. Carb looked GREAT short of the idle jet needle being bent at the tip. I bent, filed, and sanded the tip back straight and reassembled everything.

I proceeded to mix some fresh non-eth gas a little rich(40/1), filled up a trash can with water And fired her up! Took a few tries to but once she warmed up and I fine tuned the idle jet screw she was putting along steadily at a nice low idle. I let it idle in neutral for 30-45 min without a hiccup. Stopped it a few times in the process and it always started right back up on the first pull. Pulled the plugs and no signs of moisture. I know the motor set out under a carport for at least a few months, not sure of the history before that...

Of course the problem showed up on the first test drive.... she started fine, idled fine after warming up, and seemed to run ok with a little feathering of the throttle (would start losing rpm if you ran it WOT (wide open throttle.) either from an idle or even if you eased the throttle up as picking up speed. (Also had a few spots throughout the rpm range that would lose rpm if trying to accelerate to fast) Seemed to run best at around 3/4 throttle. 23mph (same as my 71 18hp running WOT on the same boat....) after running it like that for a 10-15 min I got a phone call. Killed the motor, finished my call and tried to start it back up, didn't want to start.... Pulled 8-10 times, gave it a break, didn't smell flooded but I could be wrong. I finally got it to fire, almost died while going into gear... Headed back to the dock, dropped into neutral, and it died again, I pulled and pulled while my buddy backed the trailer down, finally got it started again, went into reverse alright, and died going back into fwrd.... Finally came to my sences and decided to padle it to the trailer lol!

Not sure if this is a timing linkage issue, compresion, or points related issue. I'm not even sure if this thing has points lol! Any advice on further troubleshooting would be greatly appreciated!!

Mike Wolf
 
Not sure what the compression should be but I just tested both cylinders, 71 on the top and 81 on the bottom. Correct me if i'm wrong but that seems a little low and to big of a difference between cylinders....
 
[url=https://www.tinboats.net/forum/viewtopic.php?p=332612#p332612 said:
Michaeldinpc » 59 minutes ago[/url]"]Not sure what the compression should be but I just tested both cylinders, 71 on the top and 81 on the bottom. Correct me if i'm wrong but that seems a little low and to big of a difference between cylinders....


Sounds a little low, but your compression could vary by tester so I would try a different one. Also be sure to give the same number of pulls for top and bottom.
FYI. This is a CDI motor. No points.
 
Thanks Jasper. I will try to round up another compression tester. Are the symptoms of a bad part in the CDI system similar to that of an old point system?
My understanding is if there was something broke or worn to cause low / uneven compression readings the motor wouldn't want to idle so smooth if it was warm or hot... Mine idled low and steady for 30-45 min in a trash can. Didn't have a problem till I ran it at more than an idle out on the lake. I believe an ignition / spark system problem might not show until it is been ran hard for a little while....

If I'm wrong don't bite your tongues. I'm on here cause I'm not sure where to go from here and google hasn't turned up anything else useful to trouble shoot.

Thanks again
 

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