Does anybody have a trick way to find TDC on a flatty without removing the head?

On the compression stroke, spark plug out, drop a steel BB in there and tilt the engine to make sure it rolls to the front of the piston. Put a degree wheel on the crank, be super careful not to damage the piston or head and rotate the engine forward and backwards to find where on the degree wheel it stops BTDC in each direction. Rotate the degree wheel until it reads the same in either direction. Now, stick a magnet in the spark plug hole and tilt the engine to roll the BB toward the magnet. There you go.
 
after removing the rust best i can from flywheel, i paint the flywheel,. nice coat of Rustoleum, whatever color u like. then with some of the OOOPS paint from HD i paint the fin that is TDC. actually,i paint the fins YELLOW since i run them for a bit w/o blower housing on test stand... to make sure they run... and then paint the TDC fin with another color so i can tell at a glance which way is up. isnt the groove for timing and drive key, on both the flywheel side and work side... TDC?

try not to be like the HD rider who at a party, HD running, NO BELT GUARD tween engine and trans... "what this?" reaching down to touch...
 
to really get it right, just pull the head, the flathead is prob the easiest head in the world to remove, nothing to reset or deal with, just bolt back on and a head gasket is very cheap, I seen people go the parts house and get a tube of sealant and put on the old gasket, the sealant cost more than a new head gasket for them old flatheads.
 
^^^
Nice .
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I always just used a piece of 16ga wire with 2 bends in it, the second bend at .250." Feel when the piston bumps it BTDC & ATDC. Split the difference on the degree wheel. I always keep a second "tool" like this in our trailer to diagnose a slipped flywheel at the track if someone needs.
At one time, I think EZ Bore had a TDC/pop-up tool for teching with the head on.

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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
33 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
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