I'm sorry not to get back till now but after a couple of snow storms and a 3 inch ice storm we got
real busy at work, been working long hours and getting home very late. As for the wheelhorse it
didn't make the first storm. It ran terrible and still would't take any throttle. This weekend I'll tell ya's
what was wrong and what we went through to fix it, its too long to tell right now. Got to go need to
get some sleep, getting up in 4 hours to do it all over again. I'll write this weekend....cubby
Like I said the wheelhorse performed terrible during the first snow storm that my friend brought
it to work and we both knocked our brains together to figure out what is wrong. We started it and it
would idle but when throttling up it just started popping and backfiring thru the carb, and the more throttle it would just quit. At my first instinct I thought ignition. So we pulled the flywheel and took a
look at the points, I've seen a lot of points and when they close up engines seem to run terrible or
not run at all.So I figured a good place to start first. When we got the cover off the points/condensor
assy. there was a lot of oil all over everything. When we saw this we thought for sure we had found
the problem, because oil on the points could short out the ignition. The crank seal had walked out of
its bore and oil was getting all over the points. The next day I went and got a new seal, points and
condensor. The new seal went in good and tight. We put the points and cond in and gapped them to
the specs stamped on the points cover, all things should be this easy! We then put it all back together
and fired it up, guess what it still runs the same. It idles but still wont take any throttle, pops and spits
out the carb. Although if I sneak or play with the throttle I could get it to rev up and it, for a second or
two it ran really great. But as soon as you let off the throttle and tried again it would go back to
running bad.
Shaking our heads we couldn't believe this repair made no difference at all, now were back to
square one. So I asked my friend what about the spark plug? He said its new, I said lets try another.
I pulled the plug and looking thru the plug hole I could see a lot of carbon buildup and I mean a lot.
We checked the compression and it was around 75-95 psi. I didn't know the correct spec so I didn't
know if this was good or not. We decided to pull the head and look. What we found was a lot of
carbon in the head, on the valves and top of the piston. The intake valve looked like it wasn't seating
all the way. We took the valves out and cleaned all the carbon off everything. The intake valve had
slight groove around the face but not very deep. The exhaust valve was perfect as were both seats,
amazing for a '66. It was getting late so we lapped the valves with some lapping compond and put
it all back together, just hoping this would be it. We fired it up and guess what it still runs the same
no better no worse! Now were really stumped and can't think of anything else.
The next day I called another friend who knew a guy who has his own lawn mower shop and he
said I could give him a call so I did. I told him our problem and he said there shouldn't be anything
spitting out of the carb and suspected the intake valve when I told him that it had the mark on the
face. A couple of days later we got 2 new valves and valve springs. We took the engine all apart
again and changed the valves and springs. First thing we noticed that the new springs were taller,
so just maybe the old springs weren't strong enough to close the valves. We lapped in the new valves
and adjusted the lash setting by grinding top of stem to meet specs. I thought this is crude but the
shop manual said this is hows its done. We noticed when turning the engine over upon compression
stroke one of the valves lifted up slightly and then went back down. I called the lawn mower shop
guy and he said this is normal that it has a built in compression release to aid in starting. I thought
for sure we messed something up. We put it all back together and started it up and guess what it
still runs the same no better no worse! Now what do we do? We fixed everything we found that
needed it but still hasn't fixed the original problem. The carb was changed, the ignition was worked on, we also checked spark with kv tester, it had 9 kv at idle and one time I touched plug wire when
it was running and got a good shock that I felt at both of my elbows! Pretty strong I thought. We
cleaned carbon and replaced valves and springs so whats next piston rings? And also we put old
carb back on and put fresh gas in too and still runs the same. Now were both not sleeping at night
just thinking what could be wrong.
I've been a heavy equipment mechanic for 30+ yrs and one thing I learned along the way is when
something like this stumps you is to go back to basics , by this I mean air, fuel, spark and or compression. And oh yeah walk away, get some sleep and start fresh the next day. Believe me it
works wonders. Well I didn't walk away but I did go back to basics. The very first thing I suspected
was spark or ignition and then I thought what about the coil? We didn't change it yet but we did check
its kv output , and we also checked it with ohnmeter and didn't find anything out of the ordinary with
it. We couldn't find any ohm specs online or in the manual. But the kv spec was in the manual and
was a little low for the spec. But since we could only check it at idle it was at the low end of the spec
I thought this was ok. We decided lets get the new coil as it was the only thing we didn't change
and guess what.......IT RUNS GREAT! But when we got the new coil my friend ohm tested the new
coil and its specs were identical to the old coil, go figure. It runs good now and takes full throttle.
I would have to guess that internally the old coil's insulation is breaking down between the windings,
if someone knows for sure we both would like to know. This is not the first problem thats had me
stumped and it won't be the last. I will sleep better at night until the next one.............cubby
PS also thanks to everybody who had some input along the way.
