Lawn mower problem

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I have a Honda izy powered mower, 2008 vintage. It has given me no trouble since new but has now started to act up. The mower starts first pull, still cuts the grass and the powered travel works OK. However, the speed control has started hunting. The speed falls off and then revs up, usually accompanied by a puff of black smoke from the exhaust. This goes on all the time I am mowing. It also does it when the mower is stationary and lifted off the grass, ie, no load.

Previous mowers I have owned have had the speed controlled by a paddle the cooling fan air stream, but on this one the controller spindle disappears into the mower casing under the motor and is not accessible without apparently a major dismantling job. While the engine is running, I can hold the speed control lever and the motor revs up and holds the speed constant while I am holding the lever.

Has anyone come across this problem and can suggest a solution without what sounds like an expensive servicing job?
 
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Pop the air filter off it may be a bit blocked?

Not sure what you mean about holding the control, surely the control stays where you put it?

Some of those Honda's have a bad float valve in the carburetor. If you find that turning off the petrol helps, it may well be the problem. It causes the engine to flood with petrol.

A very good mower and well worth repairing
 
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its most likely a carb problem, strip the bowl and check for crud and clean all the jets
 
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Many thanks for the suggestions, I'll have a closer look at the carb. As regards the control lever,Mursal, I misled you. The mower doesn't have a user operated speed control and the control lever I meant is the one which is part of the mower automatic speed control and is operated by a spindle coming out of the engine casing. You can actually move this by hand and it speeds up the engine, although you can't cut the grass this way. When I do this the engine speeds up and holds the speed, it doesn't hunt as it does when you leave the mower to control itself. I don't know if this information changes your thoughts as to what is wrong?
 
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OK I hadn't thought of that linkage,

Try without the air filter?

Then, it might be best to follow the advice above and clean out the carb and jets. There is an air jet (somewhere) on the carburetor that may need disgusting (it has a spring to keep it tight). Adjust when the engine is hunting. Just remember where it was when you started (how many turns out), Because if it is not the problem you will need to put it back in exactly the same place. This might help?

 
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These engines have an internal bob weight governor, and its best to leave that alone.
Its a carb problem thats causing this - either on the pilot (tickover) stage or the intermediate speed range that is governed by the emulsion tube above the main jet.
So - float bowl off (mark its orientation), float and needle valve come out when the spindle is removed, followed by the main jet (screwdriver) then the emulsion tube thats above it. Ideally clean these with carb cleaner and compressed air.
Now the awkward bit....the pilot adjustment is via a screw that has a plastic cap on that allows you only to adjust it 1/8th of a turn (anti tamper procedure).
To clean this, carb cleaner is squirted through the thin drilling next to the main carb throat (air cleaner side). If things dont come clear then, the plastic screw cover can be broken off and the pilot jet unscrewed.
That should sort the wee Izy - keep the paper air cleaner newish, fresh lube oil, and they can eat plugs...it'll last for years!
John :)
 
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Thanks for the very detailed advice. I'll have a go and let you know how I go on. Thanks again.

Sam
 
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It was the air filter! I'm sorry to say I didn't take the advice of Mursal and run the mower without the filter. I had looked at the filter and it looked perfectly clean and I couldn't believe that was the problem. I removed the carburetor - thanks for the instructions Burnerman - and cleaned everything, although everything seemed very clean, reassembled it and started the motor. It was worse than before. I thought I might have assembled it with the choke lever in the wrong position, and I think I had - I think it was running fully choked. I reassembled it again and this time started it without the air filter and it ran perfectly. I fitted the filter and it was back to the original status, hunting and puffing smoke. So, although it looked clean, the filter was obviously choked up. I actually washed it and got lots of mucky water. So I need a new filter.

Thanks again guys, and apologies to Mursal for ignoring him.
 
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Pleased thats sorted, and thanks for the feedback.
Often these air cleaners get contaminated by oil when the machine is laid over on the air cleaner side.....back on the handles is the rule here.
Happy mowing! One of the best machines around, but the cutter decks do rust.
John :)
 
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Happy days ..........

Thanks for letting us know the outcome
 
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