Hyster H50XM with GM 2.2L engine and Impco CA110 mixer was burning very rich, 10% carbon monoxide. We changed the dash pot on the mixer which is basically the only wear item and now the exhaust emissions are at 7%. No matter where we set the idle mixture screw or the power mixture valve the emissions stay at 7%. This is a special Hyster carburetor, Hyster # is 1368981.
Any ideas?
Showing items 1 - 12 of 12 results.
Thanks for the advise and help with the firing order.
1-3-4-2
Find TDC of COMPRESSION stroke for #1 cylinder (closest to fan).
When #1 is at TDC Compression stroke, the rotor is pointing at plug tower for #1 on the distributor cap. Connect #1 plug cable to that tower.
Then you connect the remaining cables in order in the direction of rotation of the distributor shaft.
Need help with a hyster 50xm inline 4 cyl. On the distributor cap, what order do the plug wires go? Cap was bad, parts come in someone threw away old marked cap.
Turned out to be a bad mixer. Installed a new one and now emissions are.1%.
I ask again- how's the spark & what regulator's installed. A weak spark will cause a rise in emissions as will a defective regulator. Is this the only lift at this location or are there multiple units?
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The spark plugs and air cleaner are new. We haven't figured out how to check the timing on this engine.
We removed the entire mixer/carb and cleaned it out and now we are at about 3.5% CO. It's coming down but still stinks.
The TVH flyer that is sent out for LP fuel systems (there are also paint, tire,chain, etc ones) lists leaner air valve options as I recall. If you don't have one I can check mine? I'm also surprised it's not a CA55 carb on that unit...
How clean is the air filter? How worn are the spark plugs,rotor and distributor cap? Is the timing set correctly? All of these will also affect your CO% also.
Sorry it does have the idle up dashpot but again that is not what I was referring to.
The top of the mixer with the diaphragm is referred to as a dash pot by Impco. I am aware of the idle up dash pot on some trucks. That is not what was replaced and there is not one on this engine.
Another detail to focus on is the throttle stop screw adjustment if you are only checking CO at idle RPM.
I have seen many cases where the throttle stop screw was adjusted improperly, keeping the mixer throttle plate jacked open too far.
Having the throttle plate open too far allows the engine to breathe some extra fuel through the mixer MAIN fuel circuit in addition to the idle fuel circuit.
It is a balancing act to get the proper throttle stop adjustment AND a workable idle RPM.
In no case should the "idle up" dashpot be used to adjust engine idle RPM.
The idle up dashpot should only be very near to its operating point while not actually affecting movement or repositioning of the throttle plate until it is needed (to keep the engine from dying).
How's the ignition spark- bright blue or an orange tinted blue? How far will the spark jump?
Which regulator is on the unit?
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