symptoms...

it was running a little rough, and my son was using it to push stuff up into a slash pile for burning later in the winter... it boiled over (the radiator is toast), and blooshed the whole front of the engine in coolant. he burned out the starter motor trying to get it running, so I put a new 12V starter, solenoid, and new battery cables (old ones were in poor shape). I also had added a 10W solar battery charger so the battery wouldn't die when left parked for months.

before I started to take it apart, it would crank and crank, and barely chuffachufffa a few times if I modulate the choke while cranking before stopping. plenty of fuel smell in the exhaust gas.

when I pulled the original plugs they were black and fouled, so I gapped and put in a new set of plugs, same symptoms, occasional chuffa-chuffa-chuffa-wheeze (stop) after cranking if I have the throttle and choke just so, no sustained running.

my next step (today) will be to pull the distributor and go through the points, make sure they are gapped and static timed correctly (seen the diagrams)

then I plan on pulling hte 'new' plugs and doing a compression test on all 4. while I have the plugs out and battery back connected, I'll also check the spark.

(btw, my electronics engineering experience encompasses DC, AC, RF, and digital... I well know the difference between DC resistance and AC impedance and reactance, and I know about things like dwell and advance on older breaker point based ignition systems such as 1960s VWs).

~3.5 ohms, is that for a 12V system?
 
I think you are on the right track. Dry out the distributor and see what happens. Then do a compression test. The overheating could have warped the head or blown the head gasket, but dry out the distributor first and check for spark.
 
You'll be lucky to find a 12v coil w/ more than 2.25 ohms resistance on the primary.

6v from the factory spec'd at 0.470 to 0.510 ohms

Most replacements aren't as well made and spec at 1 to 1.5 ohms.
75 Tips
 
(quoted from post at 11:55:48 08/03/20) I think you are on the right track. Dry out the distributor and see what happens. Then do a compression test. The overheating could have warped the head or blown the head gasket, but dry out the distributor first and check for spark.

distributor interior was dry, both under the cap and back in teh points area.

the points, however, were all munged up and hte lock screw was loose.... I just tried to gap them, and when I went to tighten the lock screws, the one farthest from the points gap and adjuster cam screw stripped way too easily, so i guess I need a new base plate+points kit. sigh.

one step at a time...
 
so,,, when I reassemble this distributor, I assume I should put some grease on the bearing surfaces? what about on the cam surface that the points ride on ?

I typically use green marine waterproof bearing grease for this sort of thing, any reason I should use something else?
 
(quoted from post at 17:32:48 08/03/20) so,,, when I reassemble this distributor, I assume I should put some grease on the bearing surfaces? what about on the cam surface that the points ride on ?

I typically use green marine waterproof bearing grease for this sort of thing, any reason I should use something else?
ust about every set of points that I have purchased came with a tube of grease for the cam!
 
... so, is 110-120 PSI a reasonable compression range for these?

It took around 30 seconds after each test before the needle dropped even 10 PSI, so I assume thats adequate as a leakdown test? I didn't bother to squirt any oil in the cylinders, just pulled each plug, and screwed in the compression tester. If I had seen more leakdown, I would have done the oil trick to see if it was the rings.
 
(quoted from post at 13:59:00 08/04/20) ... so, is 110-120 PSI a reasonable compression range for these?

It took around 30 seconds after each test before the needle dropped even 10 PSI, so I assume thats adequate as a leakdown test? I didn't bother to squirt any oil in the cylinders, just pulled each plug, and screwed in the compression tester. If I had seen more leakdown, I would have done the oil trick to see if it was the rings.

oh, and that was with a cold engine, as the ditributor is currently off awaiting a new points plate, and the fuel tank is disconnected so I could raise the hood for better access, plus I need to change the radiator if I can get this thing running again.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top