1977 115 evinrude ignition trouble.

Ratvette

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Aug 25, 2021
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Hello all, first off I know this problem has been addressed before , but nothing sugested in those old threads seem to help.
I have a 1977 evinrude 115 that I purchased from a marine repair shop that was going out of business. The motor was a mechanics lien deal that had extensive work done to the tune of....The customer not being able to pay.
The motor had a complete tune up done to it. Plugs, coils, new carbs ( not rebuilt), rectifier, fuel pump and new hoses. Also had the power tilt solenoids and applicable wiring replaced.

Two weeks ago saturday I had it in the water on a 15 ft raycraft. The motor sneezed and backfired a bit at first but after I ran it a while it cleared up.
The motor ran very well. Boat is scary fast out of the hole and cruises about 45 mph with a third throttle. It gives a monster shove when you hammer wot from cruise.
All in all Im quite happy with the purchase.
We ran around about 5 hours, stopping to fish now and again, and burned 5 gallons out of a 6 gallon tank. After the last stop the motor started giving problems.
It would start and idle fine, no sneezing or the like, but when I tried to throttle up after engaging the gear it died. Took me about 5 tries to get it moving off idle. I finlly got it to go by just laying the gear in and stabbing it to wot. Once moving and on plane it was fine. Throttling down near the boat ramp it would die. It started right up again but would only accept idle speed in gear. I chalked it up to maybe only having a gallon or so of gass in the tank or maybe something in the low idle jet.
I let it set a week and last saturday gassed it up full, dismantled and blew out the carbs. Found no dirt of debris in either the carbs or the screen in the fuel pump.
I ran it on the muffs for about 30 mins and it ran great .No sneezing, in or out of gear ,and had instant throttle.
Took it to the lake sunday, and as soon as it was it the water it did the same thing. Sneezing, and wouldn't throttle above idle.
I took the rest of the day trouble shooting some things and found out that it doesnt seem to be carb related. I backed the throttle cam away from the cam lever enough and watched the movement of the timing plate and discovered that when the plate advances forward to a position just before the stop screw it will start dropping cylinders and die.
I re-adjusted the throttle cam/lever on the carb to start opening the throttle just before the position where the timing advance started dropping cylinders and dies. No luck. It seems that no matter if the throttle is opening or not, when the timing advances to a certain spot, the motor starts missing and dies. Oh and sneezes alot.
I took it out on the lake and slowly throttled it up to the point where it starts cutting out, and stabbed wot. Gets up just fine and runs like a scalded dog. Just wont throttle up smooth.
I took the time today to do some trouble shooting on my theory that it may be ignition related. Also checked tdc mark to see if the keyway may have spun, and ran a cold compression check.
Flywheel shows 0 dregrees with #1 tdc, and compression is 110 across all four cylinders.
The stator checked out at 560 ohms, even moving the advance plate.
I found the four sensor wires coming from the advance plate to the ignition box. I checked each one against ground whilest moving the advance back and forth but only noticed a slight fluctuation in ohm readings on sensor 3 .
I dont really know what I'm doing, but I'm thinking thati there may be something on or with the advance plate thats not working. Maybe a broken sensor wire where they come off the advance plate. None seem to short to ground, but im not sure how to check these wire with my multimeter, and what values I should be reading. I dont want to pull the flywheel but it seems to be unavoidable. Any input from the more experienced would be good.
 

Ratvette

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Oh one more thing, I also noticed that my inductive timing light doesn't work on this motor.
 

F_R

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Jul 7, 2006
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Taking your story as a whole, it sounds almost classic. Classic in the sense that the timer base may be sticking a bit due to improper lubrication of the bushing. As you advance the throttle, the timer base should move all the way to the full advance screw. As it does this, the carburetor butterflies only open a bit till full spark advance is reached. If the timer base sticks and fails to go to full advance, the carbs will open too soon and it will stumble, sneeze, and hesitate. Perhaps even stall.

You say you messed with the throttle cam. You may have to re-address that issue once you verify the timer base isn't sticking. Do you have the servive manual?

Yeah, some old-school timing lights won't work because the spark duration on these is very short.

Also, yeah, it is somewhat for them to sneeze until it is warmed up enough. Simply "bump" the choke momentarily to keep it going till it warms a bit.

Hope this helps.
 

Ratvette

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Aug 25, 2021
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As far as i can tell with the flywheel still on it, the timer base is moving to the advance stop screw. Unless theres something under the flywheel i dont see.
It must be something simple. It ran great, then it acted up.
 

racerone

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Dec 28, 2013
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Hard to believe that the boat goes 45 MPH with 1/3rd throttle.
 

Ratvette

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Aug 25, 2021
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As far as i can tell with the flywheel still on it, the timer base is moving to the advance stop screw. Unless theres something under the flywheel i dont see.
It must be something simple. It ran great, then it acted up.
I do have a service manual but it doesnt cover a 77 year model. More from mid 80s to 91 ish.
And my timing light is a year old adjustable type. It worked on my 88 mercury 50 just fine. Thought i would mention that it didnt work on the 77 evinrude in the original post as i thought it might have bearing on the problem.
 

Ratvette

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Not a very big or heavy boat. I have to sit center when im alone or it lists a bit.
 

Ratvette

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Aug 25, 2021
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Have no idea what pitch it has. Never looked it was on it when I got it. I actually bought it with the boat and trailer. It was on a 1978 arrow glass javalin. Boat needs transom and stringers. Is why im using the motor on the seacraft for now.
 

racerone

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Dec 28, 2013
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Better to be careful with prop selection.----As it is , you might have the wrong prop for this boat.----You run the risk of serious motor damage !!
 
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