Drill Starting your HT

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pucksterpete

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Has anyone ever started their HT engine with an electric drill? If so, how well does work and can it cause any harm by starting it this way? I am running a 66cc Grubee w/SBP Jackshaft. Too lazy to pedal on the cold starts. From what I have read pull starts are still too weak. Thanks for the input.

Pete
 
Great idea. They crank Indy cars and dragsters in a similar way.
 
This is a yes and no answer.

Yes, it does work to start the engine. You place a 14 mm socket on the magneto hex nut and with a drill (powering the socket extension), spin it clockwise. BUT... when the engine fires, the engine crankshaft will begin turning a lot faster than the now-dragging 1800 rpm of the driving socket. The end result: the magneto hex nut UNSCREWS itself right off the threads of the magneto crankshaft and will drop out of your socket and go spinning across the floor into some dark crevass in your shop. It happened to me. (Also, be sure to get a no-slop socket fit, else you will round the edges of the 14 mm hex nut. Then you have to purchase some new hex nuts.)

If someone comes up with a freewheel arrangement like the cassette on the back wheel, he will have himself a unique invention I would seriously consider purchasing. My 2-stroke engined jackshaft bike is a royal pain to start after sitting for a week or better; hence I don't ride it as much as I would like. Being able to start it in a stand in a shop would be worth a reasonable price.

MikeJ
 
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I don't know if the same applies but what the above post says is why this wouldn't work, what you need is a one way bearing. That way when the engine starts, it can spin freely. I was able to rig up a simple drill start using a one way bearing for one of my nitro Rc trucks. But I dont see how you could do it to one of these engines
 
My 2-stroke engined jackshaft bike is a royal pain to start after sitting for a week or better; hence I don't ride it as much as I would like. Being able to start it in a stand in a shop would be worth a reasonable price.

I have the same problem, for now I have been using a indoor bike trainer for a stand start. You still have to pedal your a s s off, but not the worry of dealing with it out on the street. They are a pretty penny 'new', but you can find them on craigslist for cheap.

Pete
 
man, all i do is coast down my driveway about 10 feet and pop the clutch, no peddling involved.
but, i don't have a jackshaft and i am unsure of how a jackshaft affects the starting due to the gearing.
 
Pineiroadrian -

So you have the concept in practice? I take it larger versions of that one-way bearing exists. When there is a will, there is a way. If I can get a drill on one side of that bearing and a 14 mm socket on the other side, the rest of the effort is trivial.

MikeJ
 
I too have done the drill trick on new engines because they are a bear to start the first time. I have yet to lose the mag nut though but I suppose it is possible. I have also heard the newer pull starters are much improved.

Still having a hard time understanding the difficulty in starting a cold engine though. I can get mine to fire after sitting for 6 months in less than 50 ft. The problem with the cold start is no fuel so what I do is put the choke on full, press the primer button until I see a few bubbles come up the fuel line, this means I am replenishing the empty float bowl. Then she always fires right up. I must say good ignition helps too. Good plug and good plug wire are a must. Although I haven't tried one, Pablo says the NGK iridium decreases the starting time significantly.
 
Pineiroadrian -

So you have the concept in practice? I take it larger versions of that one-way bearing exists. When there is a will, there is a way. If I can get a drill on one side of that bearing and a 14 mm socket on the other side, the rest of the effort is trivial.

MikeJ

yes actually, there are larger versions of that bearing. but the tiny one i use for my rc truck is $25. i already have an idea for a setup that would start these bikes right up without unscrewing the magneto nut.

look at the below diagram i made :)
 

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Hi Ghost0 -

Thanks for the words of experience. I admit my difficulties are most likely fuel delivery related, especially during startup efforts. I have to spend some more time on that. Once I get the engine started, I have been known to ride my SBP-jackshaft bike over 100 miles in a given day, repeated no less than eight times.

Pineiroadrian - Thanks for the drawing. I'm going to have to pursue a duplicate. Imagine... Take this on the road and claim to have an electric starter (ie, small drill). You would have to demonstrate to the non-believers!

I have been sidetracked with work at a remote site for the past seven months and have been working on another build. I will try posting pictures in a week or so...

Thanks,
Mike
 
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