I posted this on another forum:
SIL purchased this non-running 9N. It wouldn't even turn over.
This 9N is proving to be a huge test of my wrenching abilities, or lack there of.
Seems everything I do to it improves it for a time, then it reverts back to missing, back firing and lacking power.
To recap, the following is new:
points
condenser
rotor
dist cap
6v coil (with new home made rubber gasket)
plugs
plug wires
fuel bowl/cutoff
fuel line
floats tested - good
needle valve and seat
adjustable main jet adjuster (original was broken off)
(replaced carb with new after market brand)
starter push button
new ign toggle switch
solenoid
rewired OEM resister
added additional resister
battery.
rewired ign circuit
rewired and corrected 3 wire GM alternator (it charges)
Added isolation diode to alternator to prevent constant drain and run-on after key switch is turned off.
Topped off fuel tank with new clean gas
The plug wires were the last item I added.
Before I added them, the engine was running pretty good at all rpm and I was able to adjust it down to around 450 rpm for idle. It would start easily and I drove it all over my place.
Governor seemed to react slow but would increase/decrease rpm depending upon load.
After a combined hr or so of running over the course of a couple days it started missing badly and wouldn't run WOT. Pulling the choke would kill it so it didn't act like a fuel problem. atleast not a lack of fuel.
Double checked float setting (1/4" from lowest float point to carb housing with gasket in place) and double checked to make sure fuel wasn't flooding (it wasn't).
Pulled dist, rechecked gap (0.015), found advance flyweights froze closed, cleaned and freed them up. Set timing to 1/4" from mounting hole with straight edge. Put it back together and it ran great for awhile then started missing again.
Thinking the miss-matched plug wires may be bad I swapped them. No change in missing, backfiring and no WOT.
Engine misses badly, at times actin like it's only hitting on 2 or 3 cylinders and every now and then it will smooth out like it's hitting on all cyls.
Going to pull dist again tomorrow and double check everything again.
Since it did run great I'm not thinking burnt valves but haven't ruled out sticking valves.
Have to study up on checking that with as little disassembly as possible.
I did pull the dist again and nothing jumped out at me as being wrong. The points seem to open/close properly and conduct when close and don;t conduct when open,
The shaft doesn't seem to have any side play but the whole top bracket that holds the bushing seems somewhat flimsey but I don't know if it's normal or not.
Threw a new aftermarket carb to it, no change.
I'll be doing a compression test this weekend but somehow still think it's either ign or fuel related.
What am I overlooking?
SIL purchased this non-running 9N. It wouldn't even turn over.
This 9N is proving to be a huge test of my wrenching abilities, or lack there of.
Seems everything I do to it improves it for a time, then it reverts back to missing, back firing and lacking power.
To recap, the following is new:
points
condenser
rotor
dist cap
6v coil (with new home made rubber gasket)
plugs
plug wires
fuel bowl/cutoff
fuel line
floats tested - good
needle valve and seat
adjustable main jet adjuster (original was broken off)
(replaced carb with new after market brand)
starter push button
new ign toggle switch
solenoid
rewired OEM resister
added additional resister
battery.
rewired ign circuit
rewired and corrected 3 wire GM alternator (it charges)
Added isolation diode to alternator to prevent constant drain and run-on after key switch is turned off.
Topped off fuel tank with new clean gas
The plug wires were the last item I added.
Before I added them, the engine was running pretty good at all rpm and I was able to adjust it down to around 450 rpm for idle. It would start easily and I drove it all over my place.
Governor seemed to react slow but would increase/decrease rpm depending upon load.
After a combined hr or so of running over the course of a couple days it started missing badly and wouldn't run WOT. Pulling the choke would kill it so it didn't act like a fuel problem. atleast not a lack of fuel.
Double checked float setting (1/4" from lowest float point to carb housing with gasket in place) and double checked to make sure fuel wasn't flooding (it wasn't).
Pulled dist, rechecked gap (0.015), found advance flyweights froze closed, cleaned and freed them up. Set timing to 1/4" from mounting hole with straight edge. Put it back together and it ran great for awhile then started missing again.
Thinking the miss-matched plug wires may be bad I swapped them. No change in missing, backfiring and no WOT.
Engine misses badly, at times actin like it's only hitting on 2 or 3 cylinders and every now and then it will smooth out like it's hitting on all cyls.
Going to pull dist again tomorrow and double check everything again.
Since it did run great I'm not thinking burnt valves but haven't ruled out sticking valves.
Have to study up on checking that with as little disassembly as possible.
I did pull the dist again and nothing jumped out at me as being wrong. The points seem to open/close properly and conduct when close and don;t conduct when open,
The shaft doesn't seem to have any side play but the whole top bracket that holds the bushing seems somewhat flimsey but I don't know if it's normal or not.
Threw a new aftermarket carb to it, no change.
I'll be doing a compression test this weekend but somehow still think it's either ign or fuel related.
What am I overlooking?