TD .051 crankshaft end play

duaneh on Fri Mar 13, 2020 11:21 pm

I picked up this TD at a swap meet a few weeks ago. I felt sorry for it, it had been "rode hard and put away wet". Here it is after cleanup.

It still has strong compression, and should be a good runner - except for one thing. There is already a shim on the crank, but it still has .025" end play. There is also scuffing on the back plate from the crank pin.

Is it OK to run the engine in this condition? Can I just add more shims to take up the excess end play?

balogh on Sat Mar 14, 2020 1:06 am

Unless used in a pusher service the engine should work fine with one more srainless steel washer added behind the backplate.
Gun shop sell gun blue fluid with which you can conjure back the nice signature black color of the cylinder.

Ken Cook on Sat Mar 14, 2020 7:10 am

Is the drive washer completely bottomed out on the shaft? Tightening a prop onto it won't be enough point force to push it back. I use a 5-40 socket head with a nut and screw the socket head in all the way and back the nut down to insure it's all the way on.

duaneh on Sat Mar 14, 2020 10:32 am

Ken, I noticed the end play as soon as I got the engine unstuck, so it was there before I removed the crank. Still, that doesn't prove the drive washer was fully seated before. When I re-installed it, I did use a prop to seat it. Your method sounds better. I will try to source a 5-40 hex nut to do the same.

Balogh, thanks for the advice. Good to know I can at least give it a test run. I will get a shim washer on order. My "other" hobby is guns, so I have cold blue on hand. The cylinder is heavily pitted, I'm not sure fresh bluing would improve things very much.

**Cribbs74** on Sat Mar 14, 2020 11:47 am

More than likely an electric starter was used on it which would account for the increase in play.

Phenolic washers can be sanded down to fit to clear up the gap, but to be honest it will run fine as is, I have several with excessive play and they work just fine. Backplate scuffing occurs even on new engines.

As to the cylinder pitting, you would be surprised what a wire wheel will clean up, although it will work fine as. If it’s a runner and not a display piece then it doesn’t really matter. Personally I would clean it up and re-blue it. Your engine your choice! Have fun with it.

Ron

roddie on Sat Mar 14, 2020 1:29 pm

Cribbs74 wrote:More than likely an electric starter was used on it which would account for the increase in play.

Ron

Yes.. and the crankpin-marks on the backplate too. Most experienced Cox engine owners know; their engines don't require a heavy-hand to start. I've seen the noses of models fractured.. (if not torn-off..) when a "Big Ol' electric starter" was used on a flooded engine.

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TD .051 crankshaft end play

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