major backfiring

I'm trying to finish off a refurb of an old Ferguson TE20 I  helped a high school Ag class with.

thanks,  I did recheck that.

How deep into the engine did the refurb go?  Anything to possibly change timing sequence.....  You indicated it ran good for a bit..was that with all the new tuneup parts or after?    Eliminating backfire but no sustained running  you said....was it just not backfiring while cranking or did it actually run?   Never had one that needed a muffler to fire.

btw kicking the back tire really hard didn't help at all except it kept me from cussing in front of students... 

1432 is correct going the wright way around the cap check dist rotation

I'm with the guys who say it's a timing issue as in fireing at wrong times.  Re check everything again, starting with valve lash, with all plugs out turn  engine till it comes up on number one COMPRESSION stroke till the FIRE line is register with pointer. With ignition on and dist. retarded turn dist in the advance direction till you get a spark to number one wire/plug.  Confirm the rest of the wires are (plug) conected to the right plugs. If all this has same result install old cap and rotor and see if that is the problem.  Keep us posted !!

Tuck & others in the timing camp - yep, we pulled the valve cover and watched so we got TDC while both valves closed on #1.  also rechecked all clearances.

Ignition parts are junk these days. I would try the old points and condenser and see if that helps. It will make you pull your hair out seeming like all sorts of other problems.

be nice to know if the timing gears do line up . 

Cleaned up and reseated valves is a term that leaves me scratching my head! It skips over the details of what was actually done.
You might do a compression check to see what you got for your time in cleaning and reseating the valves. Checking or rechecking the valve lash/gap would also be in order.

If you set the engine on true TDC you can loosen the distributor and rotate it back and fourth with the (switch on) watching the points for sparks when the points open. When the points are (just) about to open lock the distributor down and you are in time ready to run assuming that the advance is not hung up/rusted fast. You should be able to check the advance by turning the rotor feeling the advance springs pulling it back. If the advance was checked and taken apart it may not have been assembled back correctly.

A lot of details to check when kids are learning even with a somewhat sharp eye looking on.

Have fun.


Edited by Dick L - 02 Jun 2018 at 1:32pm

I have never had confidence in lapping by hand without facing the seats and valves first. To me lapping valves is a last step in checking for a perfect seal after grinding and facing not to just get a seal.


If you have the timing correct with spark and have good compression all that is left to make it run is proper fuel mixture in the firing chamber under compression.

You mentioned wondering about the valve guides. Lapping with a suction cup with sloppy valve guides would let the down pressure on a slight angle move the stem sideways slightly.

You might want to recheck the compression. Others have mentioned the intake gasket leaking being a possibility. Like I said before, have fun, checking the (details)

Edited by Dick L - 02 Jun 2018 at 3:57pm

Keep us informed of what you find. Always fun when people dig back thru details to find what was missed. Not near as much fun digging thru your own missed details. Sometimes it seems as though to miss something that obvious you wouldn't be able to recall your own name to miss it.

I am at present training a job setter to set molds, start up the job as well as disassemble molds, change inserts and re assemble the molds. Almost harder work than just doing it myself. I find myself telling him to move over and let me do it rather than repeating instructions in different terms that might help him understand better. Not his fault! I was able to learn one job at a time is something I have to keep reminding myself of.

Totally agree! been doing that for four months. Trained dozens and dozens of people when I was running 24 hours a day 6 days a week for thirty some years. Never Sunday! Only one job at a time though. Mold work was done in my tool shop rather than part of molding by tool and die people. The last ten years has just been myself and one or two employees running my product rather than other companies products. I did all the mold sets and tool work after getting rid of the last tool maker and foreman. Dixie has been pressing me to train someone to help me since I work from a wheelchair or stool and thinking I am old being only a few days from 80.