1960 lark 2 40 horse problems (updated w/pic)

[bashr52]

Re: 1960 lark 2 40 horse problems (updated w/pic)

Well the prop will be back from the shop next friday. I am considering buying a used one just to keep as a spare in case I get into this situaton again (I sure hope not!). So whould the pin that is in there shear (if it is still the stainless one?).

I'm thinking about how the engine cut out momentarily on a cylinder, and then once the power was reduced for a few seconds, it came back in again. Is it possible the run-away/over speed switch could be faulty? I think next time I'm out I'll try disconnecting the lower mag wire from the switch and see if it does it again. If not, I'm going to suspect the cut-out switch was kicking in for some reason.

I just had another idea. If that prob was spinning on the hub, the overspeed may have kicked in to prevent the engine from over-reving??

 

[Willyclay]

Re: 1960 lark 2 40 horse problems (updated w/pic)

The rubber clutch in the prop hub will slip long before there is enough force to shear the correct drive pin. Check in the manual I sent you for the torque test for prop hubs. If you do buy a used prop for a spare, at least you can test it before trying it. Good thinking about the overspeed switch. Temporarily by-passing it might finally answer the question about spark loss to the lower cylinder. It may very well have been kicking in during the spun prop events. Good luck!

 

[bashr52]

Re: 1960 lark 2 40 horse problems (updated w/pic)

Well the prob was 2.5 hours late getting back to the shop yesterday, but I got it! New hub looks good. The just did the hub, left the prop alone. When I got home I dressed down all the nicks with a file, took an air snader with 80 grit on it, and stripped it bare. Then I used the sander to round off any sharp edges. A little cleaning, 2 coats of primer, and 3 goats of Automotive High-Gloss Black, and it looks like a new prop, for 1/3 the price. I like this paint because it's wet sandable/buffable, althought I'll leave it as is since it will just be submerged (although you can see it did pick up some bugs/dirt in the paint from hanging outside)

 

[bashr52]

Re: 1960 lark 2 40 horse problems (updated w/pic)

Well I took it out on monday to test the new prop. Works awesome! Immediately when I tried to start the thing though, it was firing on just one cylinder. Finally got it going, and was motoring along, and the bottom cylinder would cut in and out, and eventually stayed on. On our way back ot the launch at the end of the day, it died again and was just running on the top. I had enough of that crap so I bought a genuine OMC tune-up kit, complete with 2 new sets of points (second set now) and 2 condensors. Took it out yesterday, and performed flawlessly! Ran the best it ever has! Turns out it was a little lean at WOT, added some mixture and it picked up a few knots. It's almost scary fast when you're alone in it.

The only other question I have, it seems like once I shut it off, there is a bit of an oil slick around the back of the engine. It seems like any unused gas in the cylinders will run out and float around. Is that normal?

 

[lindy46]

Re: 1960 lark 2 40 horse problems (updated w/pic)

Probably just unburnt gas/oil - pretty normal with the older engines.