1972 Evinrude 25202r compression

[Rjybilcom]

Still having problems getting this motor to start. Using a cheap inline tester from Autozone, I have spark on both cylinders and I'm using J4C spark plugs gapped at .030. Compression gauge shows about 80 psi on both cylinders. Pulled the fuel line off the barb where it goes to the carb and cranked it, strong squirts of fuel but they were using what looks like vacuum hose. Replaced that with 1/4" fuel line with clamps. It coughs and sputters now, which is more than it was doing last weekend, but still no start. Had it in a shop earlier in the year, they (supposedly) rebuilt carb and water pump and replaced points and condensers. It was running pretty good all summer, then one weekend I put it in the lake and would not start. Got to admit, I can work on my F150 but don't have a lot of experience with outboard motors. Talked to a guy at a different shop, he told me to start with a compression check but I don't remember him telling me what it should be. Is 80 too low for this model 25 hp?

 

[saltchuckmatt]

Still having problems getting this motor to start. Using a cheap inline tester from Autozone, I have spark on both cylinders and I'm using J4C spark plugs gapped at .030. Compression gauge shows about 80 psi on both cylinders. Pulled the fuel line off the barb where it goes to the carb and cranked it, strong squirts of fuel but they were using what looks like vacuum hose. Replaced that with 1/4" fuel line with clamps. It coughs and sputters now, which is more than it was doing last weekend, but still no start. Had it in a shop earlier in the year, they (supposedly) rebuilt carb and water pump and replaced points and condensers. It was running pretty good all summer, then one weekend I put it in the lake and would not start. Got to admit, I can work on my F150 but don't have a lot of experience with outboard motors. Talked to a guy at a different shop, he told me to start with a compression check but I don't remember him telling me what it should be. Is 80 too low for this model 25 hp?

80's low in my book but might not explain why it's not running.
What gas are you buying? And could that vacuum hose be the culprit? See any decaying matter coming off of it?

Try a little spray bottle with 50 to 1 fuel in it, spray some in the carb and see if it starts. If it does than you know you have a fuel issue and it's probably something in the carb.

Fairly easy to clean.

 

[Rjybilcom]

Vacuum hose is gone to the dumpster, replaced with regular 1/4" fuel line from Autozone. I wondered about the gas, I've got half a tank but its left from last year so I am going to dump it and get some fresh mix. There is a Mapco nearby that has ethanol free mid grade, it's usually what I put in my Harley, but I didn't think a 2 stroke was all that picky.

 

[saltchuckmatt]

Vacuum hose is gone to the dumpster, replaced with regular 1/4" fuel line from Autozone. I wondered about the gas, I've got half a tank but its left from last year so I am going to dump it and get some fresh mix. There is a Mapco nearby that has ethanol free mid grade, it's usually what I put in my Harley, but I didn't think a 2 stroke was all that picky.

Mid grade is fine. Ethanol is not, especially when storing.

Any carburator is picky....most likely you will need to clean the carb. Do the fuel test first and that should tell the story.

 

[F_R]

80 is low for a 25hp.

 

[davidmbv]

If you ran gas that’s is older and had ethanol in it and u did not add a fuel stabilizer, I would dump it, shoot compressed air through fuel lines. Then clean and rebuild the carb. OMC kits cheap online. I’ve had similar issues before I started using fuel stabilizer in every tank. I can only get ethanol mixed gas where I live and it goes bad quickly. I have a 72 25 Johnson. That compression sound low but could be your tester.

 

[racerone]

You have spark with plugs laying on the block ??-----Not a good test.-----Does spark jump a gap of 1/4" or more??-----That is the test.-----Or put a few drops of fuel in each plug hole.-----It should bark like a wild dog for a second.