Clark Michigan 35A Hesitation/no power

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This loader has a Continental F226 flathead 6 cylinder engine, pretty much what came in millions of fork lifts since the 40's. It has a Pertronix HEI, electric fuel pump, new spark plugs. We rely on the loader to move firewood, feed horses, and do other farm chores. I'm from the OBD2 era so I didn't learn on tractors and such...

Essentially the loader ran incredible when we put the HEI, the fuel pump and etc on it 10 years ago. Now, it will rev out to the governor, but you have to feather the throttle. If you swat the throttle off idle, it will kill the engine. If you try to go uphill, it bogs down. If its bad enough (seems to vary with the weather), it won't even have enough power to move the machine at all on flat ground. you have to rev it out and dump it in gear to get it to move in spurts.

Dad and I both have tried to fix this for 2 years now and its on and off and has been getting to the point where it's doing this every time we use it.

Dad put on a new distributor cap, changed the oil and messed with it for several hours the other day.

Today I bought and installed a new NAPA coil, after beating a grounding problem to death on the old coil. No improvement. Drained the carb bowl, removed the needles and cleaned the passages with carb clean, no improvement. I tore down the distributor and cleaned the rotor (that helped, but the machine was also at operating temp). I noticed the advance on the distributor was rough, so i cleaned up some slight wear grooves, removed the rust and dielectric greased it. Advance is smooth as silk now. No improvement. Checked all the intake manifold bolts to assure good vacuum- we recently replaced the gasket, no obvious issues.

I googled the daylights out of the Pertronix issue. The HEI either works or it doesn't, according to Pertronix and people who DID have problems (none of which seem to match mine) seem to have a grounding issue, either on the ignitor to the plate in the distributor (seems okay to me) or the distributor to the machine. I'm assuming the - terminal on the coil (where the black wire on the ignitor goes) is grounded? Or we will have to clean the distributor's contact to the block near the timing clamp. Will run resistance checks from the distributor to the battery ground to see if there is resistance.

Dad has a timing light, we are going to check for an ignition timing problem.

Carb is suspect, was dirty and adjustment and external tinkering doesn't seem to help.

Just stumped....
 
Carb clean, ignition set properly and advance working great. Air cleaner is not plugged still runs the same when disconnected.

Last thing is the thermostat. You can touch the engine block when it's at temp, dad's thinking the thermostat may have failed and it's just not getting warm enough to run 100%.
 
Replaced the hydraulic return filter, no improvement.

Replaced the thermostat, no improvement.

Carburetor adjustment on the fuel seems to have no real effect until you either bottom the needle or pull it out altogether.

I seem to be able to get bursts of power from the machine if I use 50% choke before needing power. It runs like a car carburetor with the accelerator pump broken.
 
Bpkeeper not stupid at all. The machine had a rusty tank problem so we have a huge 5"x8" fuel filter with a water drain on it, with an electronic fuel pump with a secondary fuel filter on the inlet of the pump. When you pull the carb bowl drain and turn on the ignition, it comes out of the carb with force, practically. It's been an issue in the past.

Dad and I were discussing the issue yesterday and he recently replaced the cap and rotor, gapped the plugs and cleaned them.

I might run a compression test... https://www.foleyengines.com/tech-t...ket-longevity-continental-industrial-engines/

If head gaskets are a problem.. but I don't have any coolant in the oil or etc, maybe a compression leak between cylinders. Maybe.
 
Sounds like a carb issue. It running differently when using the choke would not point me to an ignition issue.

I have a Yale forklift with that engine. Was gas, but got switched to propane at some point. Gas tank rotted out.
 
Don't know if it helps,but just spend several hundred on my tractor, had the same problem.
Last thing I did (of course ,why would I keep going?),changed the pertronix back to points and condenser.
Fixed it.Pickup coil tested good with their troubleshooting guide,I guess so much for that.JMHO
 
Ran fine,parked it for a couple weeks,came back,wouldn't start.Finally staryed ran rough,put it in gear died,no power,rough idle IF you got it started.But,once warm it ran fine (considering?)Not a wrench,but wondered if these go weak over time?.Checked the ignition module (forgot how ,but basically hooked it up to test (called them in California ).Tested good !!
Long story short,rebuilt the carb,new plugs,wires,New solenoid (damn near burned the tractor down that day!),new battery.
Ignition module fired but not strong enough?Yellow spark from plugs.
Went back changed it back to points and condenser,fired right up.
 
Well, it won't start now. Killed the battery cranking even off the block heater on it for 3 hours. It will fire but only hit on 1-2 cylinders and dies immediately when you leave off the starter. Can't get any more out of it than that. Nice, considering that I use it to feed animals (hungry) and move firewood (empty). To this point it was actually usable just... Difficult. Now it's dead :(

It's gotta be that ignition module deal... Thanks woodchuck for yakjyakjta the time to let me know what you went through
 
I did the same thing!RAN battery down,then something shortened out,melted solenoid and battery post!Not funny,I know.
Do you have all the parts to try to put your points and condenser back in?
You have nothing to loose at this point,I guess
 
The old distributor and shaft wore out, was the reason we replaced it with the Pertronix unit.

We finally after two dead batteries and 2 hours of diagnosis, popped the distributor cap and cleaned it out with contact cleaner and the stupid thing lit off and ran enough to get the job done. I think it's safe to say that a cap and rotor might be all we need...
 
Well, it won't start now. Killed the battery cranking even off the block heater on it for 3 hours. It will fire but only hit on 1-2 cylinders and dies immediately when you leave off the starter. Can't get any more out of it than that. Nice, considering that I use it to feed animals (hungry) and move firewood (empty). To this point it was actually usable just... Difficult. Now it's dead :(

It's gotta be that ignition module deal... Thanks woodchuck for yakjyakjta the time to let me know what you went through

You try giving it a snort of ether?


A cap and rotor are pretty cheap, I'd replace if you suspect it's worn out.
It'd have to been really knarly for it to cause the engine to not run though. I'd have to wonder if it has a weak spark, either coil issue or that Pertonix dealio. I don't recall those being too fussy though. Not sure what I have on my forklift, pretty sure it's still points.

Normally these engines start easy, at least all the ones I've dealt with. Could be -40* and just have to tap the key and it's chugging away.
Converting to 12v is one of the better things to do if yours is still 6v.
 
Yes, we tried lots of ether, cleaning the plugs up, messing with the fuel, rechecking ignition wiring, rechecking spark plug wires. The coil is brand new as of a couple weeks ago. The whole Pertronix distributor deal is from 2010 brand new. The machine is 12v and the battery is new last year, no clogged filters, for all intents and purposes, machine should run strong. This machine has always been hard starting. It has hydraulic pumps and a big torque converter to turn with no bypasses. The intake gasket and the Pertronix distributor helped a huge amount in 2010.

The distributor cap gets full of white dust as if the lugs inside are exploding with the spark or corroding due to moisture or something. Dad theorizes that because the thermostat was bad for so long, it may not get hot enough to burn off the moisture inside the distributor.

He had cleaned inside of it only a month ago, not replaced it ... so obviously there is some kind of damage to the plastic allowing it to carbon arc inside. It was full of white dust by the lugs inside.
 
Sounds like its acting like it has a vacuum leak as well. Any chance the carb is loose, or base gasket damaged? once its running, take some ether or brake clean around the intake gaskets. If it revs in certain areas you found your problem.
 
I totally agree with you on that. It reacts very poorly to changes in load, indicating a vac leak. It kills the engine immediately to cover the carburetor inlet and it has not responded to the spray test.

I'm not too well versed on how a distributor ignition works but since the hesitation is when the distributor is running in advance, I guess I'm theorizing that the rotor position changes and might force the ignition to jump a larger gap, there in if there is a path of lesser resistance, it's going there instead, causing the hesitation as a loss of spark. Timing light indicates that the distributor advances and there is impulse but maybe not hot enough spark to fire the extra fuel etc
 
With the new cap and rotor there was no improvement over the cleaned up cap and rotor. Machine still has off idle hesitation that makes it super annoying to use. The machine now has power and will run and work at this time and second gear in the trans is useable. If machine is snap revved off idle it will literally kill. If you snap rev off rev, it runs fine. Most of what we use it for is for tight areas and intermittent work, so we're literally snap revving all the time. Have to tap throttle to get past hesitation every time you want to move or use hydraulics.

I poured 2/3 can of seafoam in it and ran it a bit hauling brush and hay, got the job done. Thinking that I need to adjust the idle higher maybe nf just couny my blessings that it runs at all. Dad does have the idle set very low so you can almost hear each cylinder firing...
 
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