Timing mark jumping

[John1010c]

Greetings gentlemen, I have a 1963 jd 1010 crawler "gas". I have done a full restoration on it. The problem I'm having is when you try to throttle up you get a little spitting and sputtering before it accelerates. When the engine is good and warm its not as bad but still does it. It has a prestolite IBT-4101 distributor on it. My timing line is jumping a little while using a timing light. Maybe a quarter inch. I have replaced the weight springs and points and condenser. The shaft collar on the bottom of the distributor seems to had nice square edges.
Any input would be appreciated.

 

[560Dennis]

I had that with 30 year spark plug wires on the old car . Don’t know it helps In your case , head scratcher On my end.
All my timing lights did it , thunder !

 

[John1010c]

I had that with 30 year spark plug wires on the old car . Don’t know it helps In your case , head scratcher On my end.
All my timing lights did it , thunder !

Thanks for the reply. All new wires, plugs, rotor points and coil.

 

[Nordic]

Sputtering on acceleration can be a carburetor issue but what is very likely, is too much clearance in the distributor shaft bushings. Because the point gap will vary for that reason, your timing mark will jump around. I had the exact same problem with a little Allis dozer, instead of getting the distributor re-bushed I installed Pertronix electronic ignition and that became a 100% fix.

 

[John1010c]

Sputtering on acceleration can be a carburetor issue but what is very likely, is too much clearance in the distributor shaft bushings. Because the point gap will vary for that reason, your timing mark will jump around. I had the exact same problem with a little Allis dozer, instead of getting the distributor re-bushed I installed Pertronix electronic ignition and that became a 100% fix.

Do you know of any places that can install new bushings ? I'd like to keep it factory if possible.

 

[Nordic]

Do you know of any places that can install new bushings ? I'd like to keep it factory if possible.

Depending on if you're trying to stay local or if you're OK sending off in the mail to get fixed. There is a guy on here from time to time "Steve from New Jersey", I can't seem to find his contact info right now but someone else may drop it in this thread given a bit of time. He has an excellent reputation for this kind of work. You may find local contacts, perhaps through a machine shop but you have to watch out for what kind of rates they charge.

 

[Jim.ME]

Steve from New Jersey may be Steve, owner of B&B Custom Circuits. He has a website.

 

[Nordic]

Steve from New Jersey may be Steve, owner of B&B Custom Circuits. He has a website.

Thanks Jim, I just couldn't remember his business name.

 

[John1010c]

Thank you very much. I'll look him up and see what he can do