Flymo L470

[GrahamWright]

After a long retirement, I excavated it from a very damp location, but the safety handle ("Operator presence control") would not pull up to the handle. WD40'd the cable and it moved freely. The arm in the engine did not move. Removed (with a puller) the bladed flywheel and the arem carrying the brake had seized. I assume there should be a brake pad but there wasn't. Fixed that, reassembled, pulled the cord and it fired on the second pull!

However, it seemed to be rotating too fast and releasing the OPC did not stop the rotation. Then I could only start it on full choke but it would not run.

Everything pointed to fuel starvation so removed the carb and cleaned it.

Then it wouldn't start or even fire.

I suspect the coil is not earthed by the rather crude switch combined with the brake.

Now, (eventually!) the question.

Does anyone have a diagram showing the correct arrangement for this switch please?

Second question, I am not sure I have the springs properly installed on the throttle/choke. Should the control lever influence the governor?

Sorry for the long post - I've done my best!

 

[Burnerman]

The OPC handle incorporates a brake pad (missing) and also connects to a micro switch somewhere on the engine.
With the spark plug out, check for a spark - disconnect any thin black wires from the flywheel area and with luck the cut out switch should be bypassed.
Once you have a spark, then try to start - the engine can always be stalled by using the choke if you need to.
It could have been a good move to clean the carb before trying to start, but thats in retrospect!
I think these had a Del'Orto carburettor, but thats just from memory and the engine didn't really have a slow run position.
John

 

[GrahamWright]

The OPC handle incorporates a brake pad (missing) and also connects to a micro switch somewhere on the engine.
With the spark plug out, check for a spark - disconnect any thin black wires from the flywheel area and with luck the cut out switch should be bypassed.
Once you have a spark, then try to start - the engine can always be stalled by using the choke if you need to.
It could have been a good move to clean the carb before trying to start, but thats in retrospect!
I think these had a Del'Orto carburettor, but thats just from memory and the engine didn't really have a slow run position.
John

I have cleaned the carb and bypassed the switch ready to try to start again (but the rain is torrential at the moment!).
I'm not sure if there is a microswitch - I think it is just a wire that contacts part of the brake lever. That was the point of the question. It is not obvious what this wire is supposed to touch. I could install a microswitch I suppose but I am not sure how long it would survive the back emf from the coil.

Removing the flywheel was a challenge and my technique was to tap (M6) the three holes in the flywheel and drill a disc threaded M10 in the middle and three Ø6 holes to act as a puller. Might be a useful tip for someone.

 

[Burnerman]

Often enough, the wire from the ignition coil is held in a plastic insulator which earths out when the handle is released.....some had a toggle switch on the outer casing, if I recall - that was the Kawasaki engine.
As you took the flywheel off - are there contact breaker points beneath it?
John

 

[GrahamWright]

Often enough, the wire from the ignition coil is held in a plastic insulator which earths out when the handle is released.....some had a toggle switch on the outer casing, if I recall - that was the Kawasaki engine.
As you took the flywheel off - are there contact breaker points beneath it?
John

No contact breaker - just the mag coil.

I could put an external switch operated by the OPC handle. The existing is not what you might call "well engineered" (but doubtless cheap!).