Oil pump and distributer

[scoutpilot]

And all of the valves are set correctly and seating correctly?

[PercyUK]

Yes, did some valve and guide replacement when I fitted new pistons.
I have 130lbs compression in each pot.
I lapped each valve seat at the time and used my shop vac to pressure test them to check the seal.
As part of the diagnosis I checked the valve clearances last week and only had to adjust one. I could see no indication that any where sticking.

I don't want to do it but I am thinking about taking the front off to check the timing marks on the crank and cam pulls however in my heart I think that if they were misaligned then I would expect to see a problem all the time even at idle and all the time instead of randomly as it does at the moment.

Flumoxed is my current word for it.

[scoutpilot]

When you tune up the motor are you using either a timing light or a vacuum gauge along with a Dwell/Tachometer?

[PercyUK]

Hiya, I have used all three at various points. The vacuum is well within spec but does have a slight flutter however dwell is fine and the strobe is used more to check and set the timing as I try to diagnose the issue.
I can't believe that I am having so much trouble with a seemingly simple engine.
I have over 40 years driving and fixing old motors some of which were so worn out it wasn't funny but none ever had a misfire like this....... They smoked or leaked oil or lacked performance but they all ran 😁

[scoutpilot]

To what setting did you adjust the valves?

[PercyUK]

Hiya, 0.016 a cross the board

[Mark W.]

Not that you can really do anything about it but 95 octane (depending on research or motor method) is way to high for these engines. The fuel is burning very slow compared to what this should have. I run 12° with 7.2-1 Static compression and 87 Octane E-10 fuel.

Is the miss regular or intermittent? if regular its more likely electrical or valve if intermittent then fuel comes to mind variations on the feed.

I would also look at Distributor condition how are the bushings how are the advance springs and of course the condenser.

[scoutpilot]

May I suggest .015?

[PercyUK]

Hi Mark, the miss is irregular. I tested the fuel supply and it reads 3.5lbs well within spec. Under load things may change of course but I have also witnessed the miss in the flash of the strobe light when idling.
The dizzy is new, replaced as part of the process to eliminate the fault, and I recently changed the condenser twice just incase without result.
Scout, I will have a look at using. 015 if you think it could help.

[scoutpilot]

The original spec was for a .14 setting. Owners complained about the occasional putt-putt from the exhaust. Willys came up with .16 to solve the issue. But at .15, I've never had the putt-putt.

[PercyUK]

Hi, I always thought the difference between 0.014 and 0.016 was because one was chain driven and ours or later ones gear driven.
I will definitely have a go..... I guess the fenders coming off for the third time in as many weeks 😁

[BillT]

Percy have you had any success getting your issue solved?

[PercyUK]

Hiya, no luck yet. The tappet adjustment didn't resolve it. I have walked away from it for a few weeks to calm down and will have another go soon.
If I find the culprit I will definitely let everyone know.
Cheers

[scoutpilot]

Please do!

[BillT]

Percy it’s not ‘if I find the culprit’ it’s ‘when I find the culprit’. Good luck and keep on sleuthing!