1987 force 50 chip in crank

PW1967

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Apr 14, 2015
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So is this something I should be concerned with, or anyway to fix it without removing or replacing crank. it happened do to a loose flywheel.
 

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tommarvin

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This is what we need Frank A for.
I'm guessing what Frank A. would say, " Put the keyway in and torque it to specs,"
It's 90 foot pounds on our 125
 

Nordin

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The flywheelkey is NOT holding the flywheel. It is for locating the flywheel in right place for timing.
The taper keeps the the flywheel in place with help from the nut.

SOO lap the taper and the flywheel with Carborundum, do it in 90dg. rotation then move the flywheel 90dg and lap in 90dg rotation again.
When you lap you rotate the flywheel back and forth with a light down pressure from your hands on the flywheel.
The taper should be 80% or more cleaned by the laping. The surface should look dull lightgrey.

Clean the flywheel and the crank taper carefully, put in a new or a very good used flywheelkey and then torque to right value.
If I do not remeber wrong the value is 90 ft lb (about 110 Nm, translated in metric ).
 
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jerryjerry05

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Do what Nordin suggested.

​Since the flywheel was loose and did damage the crank??
Inspect the taper on the flywheel and if there is ANY damage replace it.
 

PW1967

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The flywheelkey is NOT holding the flywheel. It is for locating the flywheel in right place for timing.
The taper keeps the the flywheel in place with help from the nut.

SOO lap the taper and the flywheel with Carborundum, do it in 90dg. rotation then move the flywheel 90dg and lap in 90dg rotation again.
When you lap you rotate the flywheel back and forth with a light down pressure from your hands on the flywheel.
The taper should be 80% or more cleaned by the laping. The surface should look dull lightgrey.

Clean the flywheel and the crank taper carefully, put in a new or a very good used flywheelkey and then torque to right value.
If I do not remeber wrong the value is 90 ft lb (about 110 Nm, translated in metric ).

great advice, I would not have thought of that, Ive heard of valve lapping but never tried it, Is there a certain type I need, around here choice is limited to napa or car quest or orielys..

not quite sure what you mean by 90 degree rotations?
 

tommarvin

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Nov 22, 2015
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You need a factory service manual,i know where to get it for a fair price. It explains it perfectly.
I am going to send you a private message, tell me if you receive it.
 

jerryjerry05

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Pick up the flywheel and turn it 1/4 of the way around. 90d
​That way the whole taper gets lapped.
Any auto parts store will have lapping compound.
​Carborundum is just a name.
 

PW1967

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I got some valve grinding compound, followed procedure and it looked good, My key looked ok so I reinstalled it and torqued flywheel down, and went to start it and now no spark. It was starting fine before I removed flywheel, I looked at wires and do not see any damage. any idea of what to look for next, this is starting to get frustrating. I dont see any damage on flywheel but maybe I dont know what to look for? I did notice that when I was pulling it off it did not come off even, like it was binding on something until it was completely free of the shaft. does that make any sense?
 

PW1967

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Apr 14, 2015
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the magnets seem to be tight, I did the screwdriver test on both magnets, seem to be fine.
 

PW1967

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ok, I think I need to trouble shoot the ignition. I know there is directions on outboad ignition and other sites, but I dont know if I got the proper tools to do this, all I got is a cheap digital volt meter, test light and an in line spark tester. Ill include a pic of the dvm maybe someone can tell me if its compatible.

also Ill include that everything was fine until I took flywheel offf, I did do the lapping compound before re installing it, and when went to start it, no spark. I took flywheel back off to inspect wires and stuff, looked good but didn't get all the compound off flywheel, thier was some compound stuck between the magnets, hope this didn't short anything out. Also this is a 1987 force 50 with prestolite ignition. the coil paks were replaced by a dealer last year, he installed aftermarket cdi coils for the tune of about $700. Last year I had a no spark issue and couldn't figure it out so I took it in and thats what they said was wrong. I hate to take it back in if I can figure out this no spark issue myself, so any help would be greatly appreciated.
 

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PW1967

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any recommendation on one that will get the job done, without spending a lot, and do i need to get the peak reading adapter
 

tommarvin

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1. Get a Lisle 50850 spark tester, set the gap to 7/16 of an inch, do you have spark on all spark plug wires?
2. If you have coils test them next.
3. if you have CDI units test them next.
4. If you have a trigger test.
5.if you have a stator test.
6If you have a rectifier,test
Bottom line, if your grounded out some ware, no very expensive ignition part is going to help .
 

PW1967

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Ok guys, I got spark plug tester and no spark, already knew that though, I went ahead and tried to trouble shoot with the tools I had, and found trigger to be in range at 47 ohms. I get no reading or continuity on stator wires measuring blue to yellow, but do have continuity on the green wires that go to the rectifier from stator, I have not tested rectifier yet but wondering if the no continuity on the blue to yellow stator wires is telling me stator is bad?( I checked wires up and down and with magnifying glass and replaces two questionable end terminals, but stilL cant get continuity on the blue and yellow stator wire)

Just for infro my engine has the prestolite ignition, and is a 1987 or 98 Im not sure, but its a US Marine 50 horse Force. # 507y7c.
 

Nordin

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Seems your stator is bad. The resistance should be about 600-700 Ohm (do not remember the exact value) infinity or no continuity is no good.
Output from stator should be 210 V or higher DVA.

Trigger resistance should be 48-52 Ohm. Yours 47 Ohm is not the issue, seems okey. It can depend on the multimeter.
Outpur from trigger should be 0,3 V up to 0,5 V DVA.

Check the wires from stator if broken, if not change the stator.
 

tommarvin

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Nov 22, 2015
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999
Do Nordins plan, Check the stator wires very carefully., because a new cdi stator is going to be very expensive.,we have a 125hp our cdi stator costs $350.00
Maybe double check all wires aren't grounded out, There are so many ground wires, every coil has a ground,every cdi power pack has a ground, there are ground wires everywhere.
Here's the risk, you install the stator and it doesn't fix you problem, then it sits on the shelf, or you resell it on e-bay used.ouch,been there done that.
 

PW1967

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Apr 14, 2015
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I ended up purchasing a new stator, from outboard ignition ( $ 215.00 ) , installed and fired up, I guess my cheap multi meter showing no continuity did prove my stator went bad, I checked wires where they are connected to stator all the way to terminal block and nothing. but I think its time to purchase a new fluke in case I have to deal with this troublesome ignition problems again.

still don't know how its related to my flywheel key breaking, but must have spun around and broke stator some how, or being it is 29 years old it was due to go out anyway?
 

jerryjerry05

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The key can break for NO KNOWN REASON!!!!
.Brand new twin 88/ 85hp. went fishing and one motor just wouldn't start??
Got back to the shop(worked there) and found the key broken.
Didn't backfire or stutter or hit anything. Just shut it off and upon trying to start NOTHING!!
 
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