Bad bottom end?

rmak

Senior Member
After buying my 29 in a non running state, I finally got it started yesterday. I had a few problems keeping it running and I hope I didn't over rev it after starting it up, racing the engine and then running around to catch the throttle linkage before it stalled.

Anyhow, today I had a chance to get things a little sorted out. I got the carb to idle. In fact, I got it to idle at around 200 rpms. just putting.
However, now I hear a metalic sound a clicking or rattling. It kind of goes put-put-put-rattle-put-put-put-rattle.

I've used my long screwdriver, stethoscope method of listening to the internals, and I can't hear it that way. I've listened to the cylinders, valve cover, water pump, oil pan, etc and all sound like a little engine working away. But then when I get away from the engine I hear that metal sound.

I'm worried about the crank. Would the sound be consistent if there was a bad bearing/babbit or would it be intermediate? Any guess as to what it could be, and how bad it could be?

I did have the head off and all looked fine there. If you A Model gurus can diagnose the problem from my description, you are good...real good!:D

I did have
 
Timing Gear? Could be an aluminum one?Ground out each spark plug one at a time and see if the sound goes away? Keep us posted.
 
Could be the drive shaft for the distributor. I had a similar sound and turns out the lower bushing was really sloppy and would rattle around on the number 4 - would also get a little bit of a misfire on number 4 as well. Grounding the plug would not cause any difference in the running.

Just a thought.

Mike in NRN IN
 
On idle I could hear a similar clicking that was gone with an increase of RPM's. It was the water pump shaft moving in and out against the stop in the head. Increase the rpm and the fan pulled the shaft forward thus the clicking sound stopped.
 
I think the point is it could be many things, don't always think the worse, like the guys said short the plug wire (or just flip it off) will make a rod noise quiet down, a main would not come and go, if it has been sitting for a long time the valve might be sticking up and you could be hearing lifters,
One trick is to take off the belt run for a minute or two and listen if there is a noise this will take care of gen and water pump, check and see if the pulley has a two part, they will come loose,
Good luck let us know,
 
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