Keeping the faith - my lawn boy video

secaII4884

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I created a Youtube account just to post some videos of my lawn boy. Weird I know.

Recently did some work on my LB. This was a freebie from a family member that I've keep going all these years. The muffler (stamped steel) was rusted badly and had multiple holes. That's really what started my re-working of the mower. I've fitted a new (second hand) muffler, new spark plug, refinished the cork float with some Midwest Products aero gloss paint and made some carb adjustments.

I've been working on trying to set the idle. What do the pros think?

 

secaII4884

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Here where I ended with my carb adjustments. It's idling around 3200 RPM I think.

Any thoughts?

 

lewb

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Well I am not a Lawn Boy expert but I have rebuilt a couple newer LB's. The rpm is set by the governor or vane. Spring tension is what determines how much throttle so when you load the motor and the flywheel slows the spring tension will give more throttle to maintain the operating rpm. 3200 sounds about right for operating rpm. When you move throttle to low you are reducing the spring tension so the throttle will back off, usually not a great deal from operating rpm from my little experience maybe 1500 to 2000 rpm for low throttle. You adj the rpm buy turning the round or hex adjuster directly below the vane on the carb. Each click is 50 rpm, counter clockwise for hex and clock wise for round if I am not mistaken will increase, Another way on round you need to turn the direction of less throttle and hex turn toward more throttle. If that makes sense.
 

Two-Stroke

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I like that little tachometer -- the "Treysit sirometer". The running speed seems fine. At the risk of sounding nit-picky, these LB F-series engines don't really have an "idle" setting -- they just have a running speed.

I watched both videos and the mower seems to be running fine. How does it do under heavy load -- like tall, wet grass?
 

secaII4884

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I like that little tachometer -- the "Treysit sirometer". The running speed seems fine. At the risk of sounding nit-picky, these LB F-series engines don't really have an "idle" setting -- they just have a running speed.

I watched both videos and the mower seems to be running fine. How does it do under heavy load -- like tall, wet grass?

Yeah, you're right. Probably not an idle speed but more like an operating speed. Why I didn't buy a Treysit years ago I'll never know. They're worth their weight in gold. Very easy to use.

Thanks for the okay on the mower. To be honest, it was running very bad before the tune up. The previous owner must have adjusted the carb for the rusted out muffler and enriched the fuel mixture. Once I put on the new muffler, it ran horribly and was fouling plugs. Read up on how to adjust the needle valve from the service manual and what a difference. I think it was out 5 or 6 turns.

Here in the UK, the grass isn't growing very much so I can't really test the LB in tall wet grass. I can say it's very easy to start once hot. I guess we'll have to wait and see.
 
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