Evinrude 25202r WOT adjustment

[Rjybilcom]

Used carb cleaner then blew it out with compressed air

 

[oldboat1]

Check for dropping a cylinder (#19). If electricals (magneto) turns out to be OK, it may be that compression is just a bit too low to make higher rpm.

 

[Rjybilcom]

It's around 90, so that could be part of the problem.

 

[racerone]

Remove bypass covers and inspect pistons / rings.----Cost you a couple of small gaskets.----Or make them from a cereal box.

 

[Rjybilcom]

Took the tiller handle apart, got all the old caked up grease off, pulled that control arm out, made sure both sides of the plastic pin was intact where it went into the slots, sprayed some PB Blaster into the worm gears to make sure they moved freely. Greased the shaft inside the tiller handle and put back on. Reseated the metal speed indicator ring and the rubber handle. Now it turns freely and the cam roller lines up where I think it should. At the first of the 2 marks, throttle plate is barely open and by the time it's at the end of the cam, that arm is pushed away as far as it goes and the throttle plate is perfectly horizontal. This is when it's in forward gear. If it ever warms up around here, I will fill the trash can up with water so I can crank her up and see how she runs.

 

[oldboat1]

Water about half way up the motor shaft to be safe (well above the impeller). Run at only idle or high idle, -- throttle up with max. half second burst or two to be sure it doesn't stall. Fresh fuel, 50:1 mix.

 

[Rjybilcom]

I have it on a sawhorse in a trash can full of water with the hose running, it cranks right up and runs at idle. After a few seconds it stops smoking as much and you can hear the idle smooth out. I put it in forward so I could throttle it all the way up for maybe 1-2 seconds then back to idle and went back to neutral. With that being said, it's when I have it on the boat and in the water that I have problems. It runs great at low idle speed until I get away from the dock and increase throttle. It's like the revs surge up and then drop. I don't know how else to explain it. Carb has been cleaned, fuel lines have been changed, even a new fuel pump. I know I have low compression, average of 85-90 on either cylinder. And according to the inline spark tester, getting stong spark on both top and bottom now.

 

[saltchuckmatt]

I have it on a sawhorse in a trash can full of water with the hose running, it cranks right up and runs at idle. After a few seconds it stops smoking as much and you can hear the idle smooth out. I put it in forward so I could throttle it all the way up for maybe 1-2 seconds then back to idle and went back to neutral. With that being said, it's when I have it on the boat and in the water that I have problems. It runs great at low idle speed until I get away from the dock and increase throttle. It's like the revs surge up and then drop. I don't know how else to explain it. Carb has been cleaned, fuel lines have been changed, even a new fuel pump. I know I have low compression, average of 85-90 on either cylinder. And according to the inline spark tester, getting stong spark on both top and bottom now.

Not sure if this was said before but try to borrow another compression tester and see if it's different otherwise yes it could just be wore out.

Unless you have a dyno or a big test tank you can't re-creat that.

 

[jimmbo]

You have verified that the Spark can jump a 3/8" gap?

 

[oldboat1]

If you run with a portable tank for testing, but have a built-in tank in the boat, check the boat tank for water. Siphon a sample from the bottom of the tank and let it settle out in a glass jar. Fuel will separate and float on water visible at the bottom of the jar.

 

[Rjybilcom]

Portable tank both ways and it's fresh gas/ oil mix. With Sta-bil added.

 

[Rjybilcom]

So pulling the plug wires off one at a time, top cylinder is not firing.

 

[oldboat1]

Just for grins, you might test the boat tank for water.

 

[jimmbo]

Does the Top Wire provide a Spark that can jump a 3/8" gap?
If it does, check the plug. If plug is fine, check compression.

 

[Rjybilcom]

Does the Top Wire provide a Spark that can jump a 3/8" gap?
If it does, check the plug. If plug is fine, check compression.

I'm using a simple inline tester. Top wire has weak spark and will not start if I have the plug boot off the bottom spark plug. In reverse, inline tester shows very bright spark on the bottom and motor will start whether top boot is on the plug or not. I will swap the two spark plugs around tomorrow to see if maybe it's a bad spark plug. I had the flywheel off and you can check resistance on both coils all the to the plug boot, they read 5.6 to 6.1

 

[jimmbo]

What is the Gap on your Inline Tester? If less than 3/8", it can spark all day, but there is no Guarantee that once the Compression Rises in the Combustion Chamber, that will deliver a spark strong enough to jump the gap on the Spark Plug

 

[racerone]

See the spark test suggested in post #2 ???-----We all seem to think you have spark issues.----This is really simple to sort out.

 

[jimmbo]

We're not telling him what he wants to hear...

 

[Rjybilcom]

Jimmbo, looking at this tester, it looks like the gap in it is 3/8.

 

[racerone]

Glue 2 wires onto a piece of cardboard / plywood.----Space them 5/16" apart.-----Does spark jump the gap , yes or no ?