9N misses under load

[geneP]

This might have been covered many times over. If so, I apologize, I didn't find it in the archives. I have a neighbor who has owned a 9N for years. He said recently it started running really ragged and dies when under load. It idles smoothly. He's worked through the fuel system and replaced the distributor and no improvement. He has noticed that he can turn the crankshaft about 1/4 turn before the distributor slot will move. Is this too much slack, and will loose timing gears produce the symptoms he has? Thanking you in advance, Gene

 

[Soundguy]

I think he needs to pull the front timing cover and see why there is soooooo much slack. I'll bet his fibre timing gear is about to bite the big one. There are new aluminum ones.. but you will need the 4 bolt version camshaft. Or buy a used camshaft with presse don fibre gear intact.. etc.

Aside from that.. yes.. timing.. especially retarded will effect power.

I assume you have checked spark, and compression? Minimum ford spec is 90 psi dry.. on a warm engine, and no more than 10 psi between a wet reading, and no mor ethan 10 psi difference between adjacent cylinders.

70+ psi tractors still start ok ( on 12v ) and have some life left.. anything lower is a rebuild or repair candidate..

Wide points gap will also rob power.. front mount gap is .015

Soundguy

 

[geneP]

Thanks Soundguy, I thought it sounded like a lot of slack. He has the head off now because he thought it might be the valves. I don't know how he reasoned that one out. He says it idled good and smooth. The engine didn't just loose power, it goes into an irregular miss and runs really ragged. He says it will die if you don't take the load off the engine. Choking the carb doesn't help when it starts to run bad. I'll pass your comments along.

 

[Soundguy]

I've seen N's do that that had bad distribuitor bushings, thus changing the points gap for each lobe. I'd have to guess that a lot of play in the timing gear woul also cause anintermittant timing issue.. It's a good place to start.. better than the valves anyway.. though.. never hurts to look at those if ya got a new engine anyway..

Soundguy