Evinrude 25202r WOT adjustment

[Rjybilcom]

Now that I have this motor running again, I need to do some adjustments. I had the carburetor off to clean it and it doesn't seem to be getting anywhere close to WOT. I had some diagrams at one time showing the two timing marks in relation to the arm with the roller, I think called the cam follower?

 

[racerone]

Does the throttle plate go horizontal at wide open throttle ??----Reed valves checked ??----Spark that jumps a gap of 5/16" on both leads ?-----Plastic pin on tower shaft in good shape ?----Post compression values again.

 

[saltchuckmatt]

Not ex

Now that I have this motor running again, I need to do some adjustments. I had the carburetor off to clean it and it doesn't seem to be getting anywhere close to WOT. I had some diagrams at one time showing the two timing marks in relation to the arm with the roller, I think called the cam follower?

Not exactly sure on that year but what your describing is the proper way of adjusting the idle/timing which is done at the carb. The adjustment for wide open throttle is done under the flywheel on the port (left) side. There is a long rod with a set screw and that controls how far the butterfly opens. Loosen the screw, then make the butterfly perpendicular and tighten the screw. Usually takes me three times or so to get it right.

 

[Rjybilcom]

I took the boat back down to the campground yesterday, but will probably be back this weekend. Last time I did a compression test, it was an average of 85-90 on both cylinders. Will try to find my inline spark tester too, but since it's firing up and running, I didn't think there was a problem with spark. It runs pretty smooth at low idle. I've replaced the plastic roller on the cam follower and I think the butterfly is opening up all the way. It seems like when I twist the tiller handle and its in forward gear, it's not turning as far as it should. Maybe there's something going on with where the gears mesh?

 

[saltchuckmatt]

I took the boat back down to the campground yesterday, but will probably be back this weekend. Last time I did a compression test, it was an average of 85-90 on both cylinders. Will try to find my inline spark tester too, but since it's firing up and running, I didn't think there was a problem with spark. It runs pretty smooth at low idle. I've replaced the plastic roller on the cam follower and I think the butterfly is opening up all the way. It seems like when I twist the tiller handle and its in forward gear, it's not turning as far as it should. Maybe there's something going on with where the gears mesh?

If the butterfly is perfectly flat when you twist it to full throttle while in gear than your carb is set correctly.

You may want to check compression with another gauge just to be sure. Compression is low.

 

[Rjybilcom]

So when it's in gear and you twist the tiller handle all the way, the armature plate rotates and the cam follower gets pushed way by the cam, and it should get to the highest point where its far enough out the throttle plate is fully horizontal. It doesn't get far enough for that to happen. It's like the tiller handle doesn't turn far enough or the armature plate doesn't rotate far enough.

 

[Rjybilcom]

I thought compression was supposed to be around 110? This is a 1972 motor, maybe the piston rings have a little wear?

 

[saltchuckmatt]

I thought compression was supposed to be around 110? This is a 1972 motor, maybe the piston rings have a little wear?

You know I'm not quite sure about your link and sync on that older motor.

Maybe that one doesn't have that rod....my 77 does. Must have something.

Your motor new was probably 140 psi and you would hope it to be no lower than 110ish. My 77 is at 125.

Hopefully someone will come by and show you how to get it to WOT.

 

[racerone]

Check plastic pin on bottom of tower shaft.----Check gear mesh on handle.

 

[Rjybilcom]

Do you have a diagram of this tower shaft? Trying to find it on a parts schematic unless it's called something else.

 

[racerone]

Item 37 and item 41.----Officially called " control lever " by educated folks.

 

[Rjybilcom]

Got it. That lever connects to the metal link arm on the magneto. I will look at it Saturday.

 

[racerone]

Spark timing , relative to the piston in the bore is automatically controlled by linkages.-----No user adjustment possible or needed.

 

[Rjybilcom]

Had a chance to stop by the campground on the way back to Huntsville. First 2 pictures shows where the roller is on the cam and the position at WOT

 

[Rjybilcom]

This is where the gears from the tiller handle mesh and the tower shaft. I do not see a plastic pin.

 

[racerone]

Well---I can see the plastic pin in picture 2 and 3.----Look in the slot on that gear.----Huntsville , Ontario ?

 

[Rjybilcom]

Huntsville Alabama, Rocket City. The built a lot of the space shuttle and international space station here. Ok, so does the pin look right or is it sheared off?

 

[Rjybilcom]

The previous post with 2 pictures, doesn't the roller line up with the two marks on the cam, and when you twist the throttle, it's on the end of the cam?

 

[racerone]

With tiller handle at full throttle is the butterfly ( throttle plate ) horizontal , yes or no ?----Take a look at that plastic pin , is it broken , yes or no.----Present the facts to make progress on your motor.----Sounds like it might be running on 1 cylinder.-----Start motor.----Pull one plug wire off at a time.----Report what you find.

 

[oldboat1]

When cleaning the carb, did you make sure the high speed orifice was clear? (bottom front of the carb -- believe it's best not to risk damage by removal -- spray with carb spray using the plastic nozzle. If a blockage, a piece of weed whacker line works well to clean out without damaging the delicate surface.