OT sorta:Yale forklift dieing out,gas engine

redtom · Mar 1, 2011

Got a problem child at work: About 10 year old Yale forklift with gas engine, Mazda FE5. Starts runs great. Run up for about 30 seconds like you were heading out engine starts to sputter, gets alot of clatter, starts missing. Let her idle down for 20 secs or so, smooths right out and runs fine. Will run perfect at low throttle/load forever but rev it up like I said and it does that. checked all the obvious: compression good, gas good, valves adjusted proper, good oil press. Had electronic dist. Acts like a valve is sticking. All springs intact and none feel noticeably weak. Top end is splash/spray lubed to single overhead cam with solid adjusable rockers, so its not a collapsing lifter,(which is just what it sounds like). Tried running it with the valve cover off but the splash is great. Might have to come up with some sort of way to do that, though.

Bob M · Mar 1, 2011

Sounds like fuel flow problem!

If you haven't already changed the fuel filter do that first. If the problem persists with the new filter, suspect a weak fuel pump.

Russ from MN · Mar 1, 2011

I ran a Toyota once with the cover off to find a clicking noise, covered everything with plastic and some newspapers! Found the problem, a rocker was moving axially on the rocker shaft.

JDseller · Mar 1, 2011

Like the others have said check your fuel filter and pump. If they are good I would check the ignition system. I had a electronic distributor on Chev. industrial motor drive me nuts thinking it was a fuel problem and it turned out to be a electronic issue. The spark would break down when it got electrically hot. It only took about a minute. Also change the spark plugs have had them cause weird engine issues the last few years.

The clicking noise could be the ignition timing being off and causing it to ping. I mean the time off because of a firing problem not static timing.

Anonymous-0 · Mar 2, 2011

Seems it wants more fuel,did you check the supply? needle & seat? runs well for 30 seconds probably because the bowl is full.

jgilles · Mar 2, 2011

redtom, You already know what the problem is, it does have a sticking valve. I have seen it dozens of times on lift trucks with overhead cam engines. I've been wrenching on lift trucks for 32 years now. The valve springs on OHC engines are not strong enough to close the valves when the valve stems are gummed up. We use a product called "Castle Clean" that is a intake system cleaner and it works great 95% of the time. The one we use has a can of cleaner that hangs on the overhead guard with a hose attached to a vacuum fitting on the intake manifold. Run the engine at 1200 RPM and let the cleaner do its thing. Some times we have to do it twice and in the few cases that it doesn't work the head has to come off and the valves removed and cleaned.

redtom · Mar 2, 2011

Thanks for the input. a co-worker joined in and ran it with the cover off. The valves were indeed sticking.

OT sorta:Yale forklift dieing out,gas engine

redtom

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Bob M

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Russ from MN

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JDseller

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Anonymous-0

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jgilles

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redtom

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