Andy, Yes, I still have original 24v waterproof system. Doing any testing/repair with this system is a challenge. I had previously replaced the condenser, points, rotor & cap with no resultant change. I found an old thread (2013) on this forum that discusses coil testing. It shows that the prima...

I performed the pencil test and the spark is weak.
I guess this narrows search down to condenser, points, cap and coil?
I had previously installed new condenser, points and cap but got no improvement.
Is there any way to test the coil!

Andy - THANKS for your responses.

I like your idea of a weak spark - I will try the pencil trick. Is there any way to check the coil as well?

John

Did the problem appear instantly at the parade or did it come on gradually over a period of time? Came on instantly Is the engine running smooth and lacking power or does it missfire? Not smooth but not really a misfire Will it pull to the governor with no load? Yes What was the compression? As I re...

I have been battling this problem for over a year now. It first manifested itself during July 4th parade last year. When going down the road I have no power. I have trouble starting off and it will only reach about 15MPH. When I rev the engine in the yard it sounds fine. I have installed new plugs. ...

I am in the process of rebuilding the fuel pump on my M37. I can't seem to get the actuating lever to insert into the tab on the diaphragm. Should I re-install the lever and then push down on the diaphragm to try to engage or vise versa?

On my M37 I connected vacuum gauge directly to the intake manifold. I got a reading of 15 inches (with a flutter of 1 inch.) As best as I could tell by searching the archives, this reading is too low (i.e., should be at least 17 inches.) I believe retarded timing could cause a low number. Are there ...

Re: one of my original questions regarding timing marks. Attached is a picture that I got off the internet. Looks like it has TDC marked. In this picture would BTDC be below or above this mark?

I will check the float later today.
I have a dwell meter but not sure how I would hook it up with the 24v waterproof ignition.

Engine revs up nicely under no load - slight miss at idle. When I try to drive it down the road it stumbles badly and will not rev up.

UPDATE 1. I have drained the old gas and put in new - this did not help. As suggested, next I will check the timing. The manual says 2 degrees BTDC and to make a chalk mark on the pulley. When I look down at the pulley (from the engine side) I see the markings on the pulley. Would "before"...

My M37 is essentially all stock. When going down the road it has no power - I have trouble starting off and it will only reach about 30MPH. When I rev the engine in the yard it seems to work fine. I have installed new plugs. Also, I have checked the compression, fuel pump pressure, vacuum, points, c...

THANKS for the reminder on the nastiness of brake cleaner - the light bulb should have went on when my nitrile gloves started to disintegrate! At least I did not do what I used to do as a teenager (50 years ago) - blow the brake dust off with the air compressor. Used mineral spirits as suggested - w...

Working on the brakes on my M37 and so far have gone through 6 cans of brake cleaner. Was wondering if anyone has ever tried one of those hand-held mini steam cleaners (Wagner makes one for less than $100.) They advertise that it works on engines but how well does it work on "military" gre...

THANKS to all that commented. As suggested I pulled the rear drums and sure enough one of the wheel cylinders had a leak - luckily it was small enough not to saturate the linings. I will pull the two front drums and rebuild all four cylinders. Again, thanks for the help!