MTFCA Forum

My question is this.
My T started to run very poorly last year, so I decided to put in a set of new aluminum pistons. I honed out the cylinders and the walls measured stock. With that said, I replaced the original valves with the new type. ( Non-adjustable)
Now that have it back together, it’s very hard to start and when it does start, it runs better with the timer all the way down. It appears to be running on the front two cylinders, since the two back ones still look clean and have the magic marker order number on them.
I have tried timing it by the book, the spark from each plug looks hot.
I need some expert help, on what to try next.

George Schmidt
Elkhorn, Nebraska

This should be in the general discussion forum. First thing I would check is for an intake manifold leak where it feeds cylinders 3 and 4.

Sorry, I did post this on the wrong topic screen..I corrected .

George Schmidt

George - Are you running magneto & coils or distributor?

Have you checked the compression?the new valves May not be seated correctly.

It'd be an educated (slightly) guess but if the markings haven't washed off, after even a slight run, it's a lack of fuel. Vacuum/manifold leak.

George, proper spark advance depends on the engine RPM, it should run better with the spark lever fully down at a high RPM, mid range spark advance for idle or low rpm, fully retarded for starting on Bat, a couple of notches advance for starting on Mag.

I would suggest grounding out one spark plug at a time while at a mid RPM range and listen for a power drop, if there is no loss of power for a given cylinder it is not firing or running right on that cylinder. If you find a dead cylinder or two, I would then swap out those coils with the good cylinders and try again. If the problem moves to a different cylinder you have a bad coil(s). If the problem persists with the same cylinder it could be a timer or wiring problem, or as others have suggested, valves or manifold leak.