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donmoore1904

Can't get >0.013 points gap 243400 10hp B&S horiz

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donmoore1904
I recently tuned a 243431 10hp B&S, and it is running like a top. New plunger, coil, did the timing. I now have an identical motor, and I can only get .013" gap on the points. The points themselves I would say have about .035 to .040" material on each contact. I am wondering, is it too much wear on the points or is it the plunger? The motor runs, but not well. The idle is real fast, low power. People who read another thread know I had a head leak, which I tended to today and may be fixed (I don't have a compression tester). I *can* take the points out of the first motor and sub them in, but I thought I would throw this out to the intelligencia here first. I bet someone knows the answer. Thanks! Don

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donmoore1904
quote:
Originally posted by dentwizz
Sounds like either the cam lobe or the plunger are worn. I just went through that excersize on my 23D. Couldn't get any discernable lift at all.
I am worried it might be the cam lobe. I pressed in on the plunger while turning the motor over, and got very little travel. Of course it doesn't take much. I just thought I got more on my first motor's plunger doing the same exercise. Thanks for the reply. I'll see if the Simplicity people will give me a plunger and sleeve ?

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larry8200
you could put a piece of .005 feeler stock behind the points or even a peice of cardstock. If a worn plunger or cam were the problem I would think you would not be able to get the points to open. And the plunger has very small movement. Grain of salt and all :D

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donmoore1904
Update. The Simplicity dealer stated "we have never seen a worn cam cause this problem." Well, there is a first for everything. I pulled the plunger, and the back end had a weird, almost crosshatched appearance. When I placed the old plunger next to the new (supplied for free by dealer), the new is actually a little shorter. Therefore, it appears the cam is shot. I am going to go look, but does anyone reading this know if I need to have my flywheel magnet reversed for the points eliminator? I thought I saw that somewhere. Thanks, Don

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rsnik
No. If you go with a points eliminator just clip the wires at a point outside the points box, attach the wires to the pigtails of the little points eliminator chip and you are done. Some people remove the points and condenser and put the points eliminator where the points were. You get big oil leaks you have to plug if you remove the points and the points eliminator is a transistor which does not like to get hot so attaching it to the block is confusion with the concept. You can attach the points eliminator anywhere on anything that is a good ground. Changing the magnets on the flywheel is done when you convert to points free, solid state, Magnetron coil ignition. Post 1982 Briggs engines have a Magnetron coil with two trigger coils. The first trigger grounds the coil so the main magnet in the flywheel will charge the coil as it sweeps by. The second trigger breaks the ground so that field in the charged coil collapses and the voltage charge goes down your spark plug wire and grounds when it jumps the gap on your spark plug.

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donmoore1904
quote:
Originally posted by rsnik
Some people remove the points and condenser and put the points eliminator where the points were. You get big oil leaks you have to plug if you remove the points and the points eliminator is a transistor which does not like to get hot so attaching it to the block is confusion with the concept. You can attach the points eliminator anywhere on anything that is a good ground.[p] Changing the magnets on the flywheel is done when you convert to points free, solid state, Magnetron coil ignition. Post 1982 Briggs engines have a Magnetron coil with two trigger coils. The first trigger grounds the coil so the main magnet in the flywheel will charge the coil as it sweeps by. The second trigger breaks the ground so that field in the charged coil collapses and the voltage charge goes down your spark plug wire and grounds when it jumps the gap on your spark plug.
Ah. Great info. That's right - I was reading about magnetron ignitions. I am glad you pointed out the heat of the motor would be bad for the eliminator. I am an EE, but book smart doesn't always cut it. I like to be cute, and mount things cleverly - might have fallen into the trap. Thanks a lot! Don

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donmoore1904
Alright, novice reality check. Before buying the eliminator, I stuck a flashlight in the hole and the cam looked intact. I placed a new plunger and guide in the hole (loosely), and fitted the points. Sure enough, I got to .018", and the points operate. In thinking back to my assumption that the points not closing was the plunger or cam was worn (too short), I realized I had it backwards. Too long would cause the points not to close, OR sticking. I think it was just a sticky plunger. Anyway, buttoned it up and it is running. The idle speed came down by itself with the points adjustment, but the motor isn't like new. There is a nasty rat-a-tat-tat like metal on metal most of the time (valves?). The carb acts like it needs a rebuild. The first thing I am going to do is check the compression, and go from there. I know how to do the timing, but would have to set aside a few hours. I need to get back to other things like the drivetrain noise. I bought this tractor for the attachments, and I am focusing on what I didn't buy it for!

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D-17_Dave
I have rarely heard the valve train cycle on the engines. I'd be very concerned about the internals of this engine with any noticable noise being heard. I'd pull the engine and remove the pan,(easy enough) and look at the crank and rod for wear and possible noise. Since you have a cam problem anyway and if the noise is from the valve train it could be a worn cam bearing and not the cam itself. The valve spring tension on the tappets can rock a cam with worn bearing. This could be showing up as a points stroke problem.

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donmoore1904
I had shelved this for several weeks due to other projects. Now that I am back to it, my focus is drawn to the drive train (another post). But this is something I intend to return to. I took the tractor to the Simplicity dealer, and the mechanic's opinion was the pinging (which I am now calling it) is a fuel issue. Either mixture or the fuel itself. The noise comes and goes at different speeds. Pretty much goes away at higher rpm. In the middle of the range, it will be there, and then suddenly goes away. Back towards idle it is usually there. The motor runs pretty smooth, and accelerates well. Overall, the noise is not as loud as I previously thought. I intend to pull the motor soon to check the timing. I may pull the bottom off, as the last contributor suggested, to see if I can detect worn parts. I may take it to experienced eyes, as I am not sure what I will be looking at. I appreciate the suggestions.

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