45ss - cleaned the gum out - now wont start

[jimi]

45 SS was running fine. Started stalling and show loss of power and then wouldn’t start at all.



The carburetors had brown gum around jets etc so we removed the carbs, fuel filter, fuel pump and cleaned them and re-installed with new fuel lines.



Now gas appears to be getting thru (wet plugs and wet exhaust port) but no sign of life. Suspecting a flooded engine we tried to dry out motor by removing plugs and letting it air out overnight. The next day we cranked and cranked, then tried a bit of priming but still no sign of lie. We removed the plugs and found good size blue sparks so we replaced them.



Tried priming continuously while crank and got major back fire. Other than that, there are no sign of the engine even trying to fire.



Any ideas?

[mercguy]

45 SS was running fine. Started stalling and show loss of power and then wouldn’t start at all.



The carburetors had brown gum around jets etc so we removed the carbs, fuel filter, fuel pump and cleaned them and re-installed with new fuel lines.



Now gas appears to be getting thru (wet plugs and wet exhaust port) but no sign of life. Suspecting a flooded engine we tried to dry out motor by removing plugs and letting it air out overnight. The next day we cranked and cranked, then tried a bit of priming but still no sign of lie. We removed the plugs and found good size blue sparks so we replaced them.



Tried priming continuously while crank and got major back fire. Other than that, there are no sign of the engine even trying to fire.



Any ideas?

make sure the flywheel key has not sheered, OMC's are famous for that! Also, I "assume" you did a compression check first??

[jimi]

Actually when I ran it without plugs to dry it out it seem to pump air

[Jeff Akers]

jimi,
while you have the flywheel off , get some "fine" lapping compound and lap in the flywheel and crank taper. make sure you claen it all off before you put the flywheel back on !
Then replace with a new key

Here's the part # 120395........ get a few of them

[jimi]

Are the keys that soft? How often do they shear?

[ricochet112]

Spark?

Have you tested for spark yet? That system will jump 1/2" on a tester.
The keys are not soft, the taper doesn't hold and the flywheel slips, the key only locates and the taper holds it in place (when pulling flywheel it should make a good pop when it comes off).
!! After lapping flywheel to crank taper you MUST thuroughly clean both tapers with alcohol, starting fluid, acetone, ect... Even the oil on your skin is enough to cause the flywheel to slip!!

Mike

[jimi]

Yup the spark is good. That's why I was so confused.... spark and gas usually equals some kind of bang like noise...

Anyway, the key sounds like a classis weakness of the 45SS. I'll check the key out. It makes sense .... what with the major backfire but no starting like sounds.

[Tomtall]

Off time

Jimi - When you have the flywheel off,flip it over and inspect the timming magnet mounted to the CENTER of the flywheel.This split phased magnet that controls the timming of your ignition trigger can become loose and slip enough to cause timming to be out of sink. Good Luck!

[jimi]

Well it was the Key!

Tomtall The timing magnet looked fine.

I cleaned it up and put in a new key. Fired it up three times in the "shop" (wooded area where the trailer gets parked). As soon as I luanched it and hit the gas I knew it wasn't right. Three minutes later it was dead, towed it back, and guess what? The key sheared again.

We'll go to town this time on the cleaning.

ricochet112, I don't understand the lapping. How can you lap the shaft in situ?

[ricochet112]

Flywheel Lapping

If the flywheel taper or crank taper has ANY marks on it at all it will be very difficult to keep it from shearing keys.

Remove the fly key, use valve lapping compound on the tapers. With a light downward pressure on the flywheel spin it, and rotate it back and forth. Wiping it clean every minute or two, inspecting it for a nice even finish. I like a compound that has a fine and coarse, finishing with the fine.

The idea is to make a perfect mating surface between the two, remember the key only locates the flywheel to the crank, the taper holds it in place.
Under extreme conditions you can add a little loctite to the taper before installing the flywheel, it does make it difficult to remove later.

When the lapping is done the cleaning is very important too, rubbing alcohol or electric motor cleaner is what I usually use, just one grain of lapping compound and it will shear, as will any oil on the taper.

Mike Bartlett

[jimi]

Ahh... thanks.

Sound like OMC undersized the key.

Where do you get lapping compound from?

Also, how do you keep it out of the crank case seal? I can't imagine metal laddened lapping compound being good for it.

[ricochet112]

Any auto parts store has lapping compound. Iv'e never had a problem with the old debris from lapping, you could put a layer of grease around the the seal to catch the fall-out.

Mike

[jimi]

Thanks for all your help. I'll pick up some lapping compound and fix up the tapers.

PS IS there a certain torque for the flywheel nut?

[sst45jeff]

proper torque

ifyou dont tourqe the fly wheel it will sheare keys.
torque to a 105#

[jimi]

Used "valve grinding" paste to clean up the flywheel and crank shaft tapper.

Cleaned with Carb cleaner, then Acetone.

Assbled with medium strength loctite.

Torqued to 85 lbs-ft.

Worked prefectly, no more sheared keys.

Now, I just have to make it go faster

Many thanks to all......