Timing/Setting points question

Coosa River

Seaman
Joined
Nov 5, 2009
Messages
52
This old motor is a 1971 25HP Evinrude. I'm making some progress now on the bugs in it......one was a worn clutch dog causing the bump(s) at throttle up.

It does appear that a few flywheel keys have been sheared in this thing over the years, as the flywheel has some wiggle in the keyway. So, I've taken a little bit of JB Weld and tried my best to re-align the key closer to it's proper place. My motor is acting somewhat like it is a little low timing wise. I moved the points from .020 to .024 and it sounded some better.

My question is this now........By moving the point gap more open, am I setting the timing higher or lower ?

BTW- the JB Weld held up for running as of now......I pulled the flywheel back off just to see, and all looked just as I put it together.

Please give me a quick timing lesson on the point gaps thing.

Thanks,

Coosa River
 

Coosa River

Seaman
Joined
Nov 5, 2009
Messages
52
Re: Timing/Setting points question

Also....what would be classic symptoms of getting the timing too far ahead, or too far behind ?

My problem is at this time.....the rpm's are slow to come up......it really has no get up and go (jump) to it. I really don't think it is coming close to max RPM's at w.o.t. either. It is idling fine......hitting on both cylinders fine.

I tried leaning the carb up a bit, but seemed to not have much effect other than cutting (spitting) out at too lean.

Coosa River
 

rickdb1boat

Supreme Mariner
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Jan 23, 2002
Messages
11,195
Re: Timing/Setting points question

Closing the gap retards the timing. Retarding (Less) the timing will hurt performance and make it sluggy. Advancing the timing too far came cause detonation and harm the motor (Pistons).
 

steelespike

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Apr 26, 2002
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19,069
Re: Timing/Setting points question

I would go back to .020.Be sure the stator is advancing as it should.
Check the link n sink.You might see if a little choke helps it open up.
The worn keyway will throw of the timing of the magnets/relation to point opening more than actual timing.Opening the points changes the dwell points are closed for a shorter time.After resetting to .020 be sure the bore and crank are clean and dry torque to 40-45 ft lbs.
 

F_R

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Jul 7, 2006
Messages
28,226
Re: Timing/Setting points question

I would go back to .020.Be sure the stator is advancing as it should.
Check the link n sink.You might see if a little choke helps it open up.
The worn keyway will throw of the timing of the magnets/relation to point opening more than actual timing.Opening the points changes the dwell points are closed for a shorter time.After resetting to .020 be sure the bore and crank are clean and dry torque to 40-45 ft lbs.

As steelespike says. The timing is controlled by the breaker cam and points gap. Neither is related to the flywheel key---well it is in the sense that the key drives the breaker cam, so if the key is sloppy in the crank it would affect the timing. But the key and flywheel fit definatly affects the time at which the magnets pass the coil's laminations. It is a critical factor when related to the cam and points opening. If not correct, the main thing it will cause is poor spark.
 

Coosa River

Seaman
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Nov 5, 2009
Messages
52
Re: Timing/Setting points question

Fortunately the key from crank to cam is tight still....it's only the flywheel keyway that has the slack. I noticed before I reformed the keyway with the JB Weld, that the flywheel would have as much as a 1/4 inch play either way out on the perimeter of it. Of course I'm only guessing that I got the keyway groove back in in the exact position......so was thing that this is probably what is throwing the timing off a bit. I was thinking that I could compensate for it being a tad off by moving the points gap in or out......to some degree I guess.

I'm gonna set it back at .020.....see what I can do with it from there. I think this is one of those that you just got to kinda feel your way right with it.

Thanks for the info.....any more suggestions on how to deal with ole loosy goosy here, I'm all ears.

Coosa River
 

lindy46

Captain
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Nov 27, 2008
Messages
3,886
Re: Timing/Setting points question

You may want to look into a replacement flywheel.
 

Coosa River

Seaman
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Nov 5, 2009
Messages
52
Re: Timing/Setting points question

I thought about a flywheel replacement, but figured the thing would probably cost more than the motor is worth.

I went back to .020 today......the thing would barely start/run. I backed out to .024 and it started and ran much better. I'm not sure what sort of problem this may cause, but it appears to be working.....and I often go with the "if it ain't broke, don't fix it" program. I'm not really sure what else to do, as I have about tweaked in every direction possible now.

I think I'll try to cripple around on this thing for the winter like it is now.....and plan to buy a better motor before next summer.

I was planning on going to the river this weekend to see how this thing runs in real water, but seems Ida has put the Coosa out of its banks everywhere. I know I dumped 6 1/2 inches of rain out of my gauge in about 24 hrs time. Boating this river in flood water is just not smart for the most part. Logs tend to float out of this woods, and head right down the middle of the river.....and most of them you can just barely see floating. We knocked the whole foot off of a Volvo back in the 60's on one of those logs......long trip back to the truck that day.

Thanks for all you guys help. I'm slow, but am learning some.

Coosa River
 

lindy46

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Nov 27, 2008
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3,886
Re: Timing/Setting points question

I thought about a flywheel replacement, but figured the thing would probably cost more than the motor is worth.


Coosa River

Check on Ebay and at AOMCI.org webvertize. You should be able to pick up a good used one for $15-20 or so. That's about what I sell them for when I have them. Sorry, don't have one for your motor right now, but they're out there.
 

samo_ott

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Jun 18, 2006
Messages
5,125
Re: Timing/Setting points question

Is it the flywheel that has the loose fit or the crank? I would have thought it would be the crank.

Also, do the link and sync as mentioned above. That can make a big difference as it syncs the carb opening to the ignition advance. If you're not sure how to check it, just post the question.
 

steelespike

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Apr 26, 2002
Messages
19,069
Re: Timing/Setting points question

Have you played with the point setting? Is the .024 the result of testing?
Is the throttle roller picking up at the mark on the stator cam?
 

Coosa River

Seaman
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Nov 5, 2009
Messages
52
Re: Timing/Setting points question

Thanks for the ebay link..... I was thinking $150 or more if one could even be found.

Yes, it's the flywheel keyway that is buggered......the driveshaft/cam keyways look great.

I've about linked and sync'd 'til I've bout went cross eyed. I think I've read and tried about all Joe Reeves threads on it. I would rather this thing run right under proper settings, but I'm getting tired of arguing with success on this old worn out thing. I'm gonna keep my eye out for a flywheel, as I think much of the problem lays in it. I've ran old junk with wallowed keyways before, but have never came across a motor that is this sensitive about it.

Coosa River
 

Elbo

Petty Officer 2nd Class
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Sep 12, 2009
Messages
136
Re: Timing/Setting points question

Be sure you get the right flywheel.Along in that era they went from double magnets to single.Im not sure when.
 

Coosa River

Seaman
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Nov 5, 2009
Messages
52
Re: Timing/Setting points question

Follow up........thought I would let you guys know that I left the points set at .024.....took it to the river today, and it ran like a top. It would even set and Idle for several minutes before I would hear a burp, and figured it was the old carb talking when it did. I'm just not sure what to think about running it this way, but it sure was nice hearing the thing crank, run and open up.

.....and BTW, just as I preached about not getting on this river flood water because of the junk floating down river, I caught me a floating log about the size of a fence post and sheared the prop pin. No troubles....had a spare in my tackle box.

Thanks again for all the advice that you guys have given me over the last 4 weeks tinkering with this old motor. After today's trip, I feel like I finally got somewhere. I even got brave enough to fish down river this last trip.....but am gonna have to settle for catfish tomorrow night.....that river was bloody muddy, and swift.

Coosa River
 
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