Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Scale Model Gas Engines - Hit & Miss - Throttle Governed - Non-Compression – etc => Topic started by: njrich50 on August 28, 2019, 03:00:26 pm
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Got my hit and miss horizontal engine and the little wheel that has the magnet in for timing spins around because the set screw fell off somewhere and the small wheel now just spins around when trying to start, it is not tighten in.
1) How do you set the timing?
2) Where do I find this tiny set screw?
I'm a newbie , if this was a old Chevy, ford, Chrysler I would not have a problem setting top dead center. ::)
Do I set it by taking the plug out, let it fire and then set that hall effect wheel with the sensor that is screwed on the body of the engine? Look like there is lean were there to because that hall effect has a small amount of adjustment to. Also is there gap between the 2 that has to be set?
Thanks.................
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Howdy and WELCOME to the Forum!
Yes, the timing is best set near top dead center, and then you can adjust it advance or retard just a few degrees from there to find where it runs best for you and whatever fuel you choose to use. I think the Hall Effect will work regardless of actual gap, but you don't want to be rubbing the plastic housing with the timing disc, so spacing it as far away toward the flywheel as possible is what I do with mine, and that seems to work fine. Setscrew for the timing disc is undoubtedly some small metric size like M3 - 0.5 x 3.0mm long, which I think is correct, and most any decent hardware store should stock them, and possibly hobby shops as well.
Your method of watching for the spark is probably the best to use as it is hard to judge just when the Hall Effect sensor trips otherwise. A deep 8mm socket (or 5/16ths also works) makes a good spark plug wrench for these. I would not bother trying to adjust the sensor itself, as it is much easier to just adjust the disc that carries the magnet.
Hope any of this helps, but if it doesn't, get on here and ask again and no doubt someone else will pick up your questions and perhaps do a better job of answering them.
Good luck with this and be sure to let us know how you make out.
Got my hit and miss horizontal engine and the little wheel that has the magnet in for timing spins around because the set screw fell off somewhere and the small wheel now just spins around when trying to start, it is not tighten in.
1) How do you set the timing?
2) Where do I find this tiny set screw?
I'm a newbie , if this was a old Chevy, ford, Chrysler I would not have a problem setting top dead center. ::)
Do I set it by taking the plug out, let it fire and then set that hall effect wheel with the sensor that is screwed on the body of the engine? Look like there is lean were there to because that hall effect has a small amount of adjustment to. Also is there gap between the 2 that has to be set?
Thanks.................
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Hold the exhaust valve open while rotating crank and you can hear the spark. It doesn't matter which stroke because it fires every revolution. Set it neer to tdc to your liking
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With the spark plug out, find top or bottom dead center by placing a thin rod or stick into the bore and roatate to find TDC.
Then hold the wheel and mark it (mark top or bottom dead center). BDC is TDC after a half turn.
Hold the plug wire 1/8" from a head bolt, turn power on, rotate flywheel past TDC and and observe where it fires.
Try setting at TDC.
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You can see it by observing the crankshaft and the connecting rod.
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What position is the exhaust cam in relation to TDC
A few degrees before or after TDC
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The exhaust cam usually opens at or just before bottom dead center (bottom of the power stroke)
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Be careful when working on adjustments to the Hall sensor.
I destroyed the sensor by touching a contact with the Imbus key.
I replaced it with an effect Hall sensor I found in Switzerland,
I haven’t found the same No. but it works
Christian.