Propane forklift compression?

[Anonymous-0]

I recently bought a Cat forklift with a Hercules 4 cyl eng .He said the engine should be rebuilt.
You have to play with the gas pedal ,depress slightly while cranking and it will eventually start and runs OK.After warm it starts decent.I did a compression test on 3 cyls and they all read 122-125 psi. Is this adequate for an LP engine? Is the hard starting in the fuel system?THanks ,Al

 

[Morgan Flowers]

This doesn't really answer your question, but I have a Clark propane forklift with a 4 cylinder isuzu engine in it and if you don't push the gas pedal down while you are cranking it it will never start. Like yours, it starts good when warm. Not sure how they are supposed to start, but this is how mine has started since I've had it. Hope this helps, Morgan.

 

[Anonymous-0]

That sounds like decent enough compression if they're all about the same. It sounds like more of problem with the propane delivery or ignition than the engine needing a rebuild. Has it had a tune up recently?

 

[Doug in Illinois]

I can't speak for the LPG forklift, but used to have a Ford F250 4x4 on dual fuel, LPG and gasoline. It was my dad's farm truck.

The engine was VERY tired. It sounded like *#^&!! running on gasoline, even though it started better on gas than LPG.

Once it was running, switched to LPG. It smoothed right out on LPG, so it is possible the forklift engine needs an "overhaul".

But I would just leave well enough alone for now unless it gets to where it just won't start. DOUG

 

[Anonymous-0]

No on the tune up. I bought it cheap from a forklift repair shop because they said the starting problem was a weak motor,it had a rear main seal leak, and it needed a water pump. I drove around and I can't see any oil leaks.I did see water so I got the new water pump, when I took the old one off it was only the gaskets. So I am doubting his other evaluations.The distrib is turned in such a way that the vac advance blocks the removal of #4 spark plug.

 

[Steven-Id]

I would bet that the distributor shouldn't be where it is. I would try turning it so you can get the spark plug out and check the compression in that cylinder. If you have 1 dead cylinder it would be hard to start. You could bring #1 cylinder up on compression and change the plug wires on the cap, rotate the dist to set timing so the plug could be removed. As far as the lpg is there a button on the vaporizer? Years ago we had a pickup that had lp on it and to start it you would push the button and it would prime it. If you primed it the pickup would start right up.HTH


Steven

 

[willie in mn]

Seems that every engine has its own habits. Probably need to experiment & find what it likes. Former employer had 2 Hysters & a Clark on propane. Best way to start either of them was to put right foot in your pocket. They would fire right up at idle, wouldn't even cough if touched the gas pedal.
One warehouse I delivered to had a pair of Allis Chalmers on propane. One would fire right up at idle, other had to hold half throttle & push primer button.
WJ

 

[OldFarmTractor]

Some of these might have a vacuum switch or a bad secondary regulator.