Balky A-block
 

I'm have an A block engine for my '30 coupe that I can't get started. I bought it rebuilt and low mileage. I got it from a friend so I know it ran at one time. I have installed all new ignition and a rebuilt carb. I have set all spark gaps, timing and carb adjustments according to the Mechanics Handbook (several times). I am using fresh gas. I have compression (using the time honored hand over the plug hole method). There is spark right down to the plug electrode. I have tried various adjustments to the spark advance.

The doggone thing won't even spit out a smoke ring...

Any suggestions will be greatly appreciated.

Thank you,
Terry

Re: Balky A-block
 

Do you actually have fuel getting to the plugs? Do you have the petcock valve turned on so the fuel can get to the carb? Did you rebuild the carb or at least make sure the jets are clear?

You might try putting 4-5 drops of fuel in each plug hole directly and see if you can get it to cough.

If you have air, fuel, and spark, something interesting should happen.

Re: Balky A-block
 

If you have a good blue spark at the plug, I would check the timing. Are you sure the valve timing is right.

Re: Balky A-block
 

Recheck your timing. When the pin drops into the cam gear detent the distributor rotor must be in this position. When books say to have the rotor pointing "OPPOSITE" number one, it means "NEXT TO".

All freeplay must be on the leading side of the rotor, which turns CCW. In other words you may be able to move the rotor CCW a small amount, but not clockwise.

Re: Balky A-block
 

One of the best diagnostic "tools" is a can of starting fluid. If she starts on Starting fluid, it's a fuel, problem. If not, it's a spark problem. Unless it's both, but you should be able to sort that out.
Terry

Re: Balky A-block
 

Read the original post: He has spark AT THE PLUG. If you are not getting even a chuff, I would check fuel. Even a timing issue 180 degrees off will chuff and pop. Hold your hand over the carb intake while turning over. Should be some serious vacuum, and it will choke the carb. Don't hold it too long or you'll flood it. After holding your hand on the intake for a couple revs you should see some gas in the bottom of the card intake. Be very careful, especially if the timing is off, you can easily get backfire through the carb intake and start a nice gas fire. Have an extinguisher handy, also a good rag to snuff out a small fire rather than blowing extinguisher dust all over everything.

Re: Balky A-block
 

Yes he has spark, but if it is not blue it will not run. A plug can fire out of the cylinder, but might not under compression.

Re: Balky A-block
 

Thank you for the info. Using your suggestions and some other info from this forum I found out that the surfaces on the intake and exhaust manifolds were not level. I then remembered that I replaced the exhaust manifold about 10 years ago but cannot remember if the engine ever ran after that. So,,,,, I'm off to the machine shop to get manifolds "leveled".

Thanks again,

Terry

Re: Balky A-block
 

Welcome to the Barn, nice job of diagnosis. You must have had a significant leak at the intake manifold. Post some pictures when you can.

Re: Balky A-block
 

this is an easy trick to get pushmowers to keep running for the ones you prime pull start run for about 4 seconds then die. as its dying cover intake and it will suck fuel thru whatever may be blocking it.

Re: Balky A-block
 

Is the battery fully charged?