question for the techies

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Old 11-18-07, 08:09 PM
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question for the techies

I'm working on an H70 engine but when I opened it up, I noticed that the condensor wire was cut off. Running an engine without a condensor will do what?
Kinda curious. The customer told me a few things that it was doing but I would like the input of some of the technical gurus on this site to give me some of their experiences so I can learn from expert advice.
The motor is a 4 cycle Tecumseh model H70 series on a snowblower.

Thanks greatly

snoman
 
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Old 11-18-07, 08:29 PM
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a condenser is a capacitor. What it does is allow the points to open without excessive arcing (problematic with DC voltage). Arcing leads to pitted points and decreased life of the point set.

One other thing that can result from no condenser is the timing can be altered since it can take more time for the electrical flow to the coil to be interrupted, it will make the timing of the spark late.

How much later? don;t really know.
 
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Old 11-19-07, 04:20 AM
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Nap
Thanks for your reply....actually what the customer said was that it had severe kick back when trying to start. So the lack of condensor did put the motor out of time as per what you stated. Thanks again.


snoman
 
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Old 11-19-07, 12:16 PM
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The effect that a lack of a condensor would have on the ignition timing would be negligible, so, I doubt that such would create a kick-back and especially since it would retard (occur later than normal) the timing anyhow. For kick-back to occur, you would have to have an advanced timing issue, in other words, ignition firing well before the piston reaches TDC. For this issue, you need to look at the flywheel key for being sheared. By all means, though, you need to install the condensor.
 
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Old 11-19-07, 02:04 PM
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Another very big issue on the kick back is the compression release on the camshaft. Our log splitter had a 12.5 hp Briggs on it. The compression release broke and it would kick back so hard it would rip the puller out of our hand. Actually broke a finger on it. We bought a few scag mowers and got them cheap for that same reason. It's hard to believe that it would do it but it does. I thought for sure it was ignition related, but after repairing about 6 of them with that problem it definitely does cause it...
 
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Old 11-20-07, 10:24 AM
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Did it run at all without the condenser? I would be surprised if yes, but have never tried it.
 
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Old 11-20-07, 07:16 PM
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Thanks for all the replies. Yes it did run without the condensor but the owner said the kick back was pretty wicked. When I first opened it up, the timing was at .093 BTDC and the specs should be at .080. I replaced the points and condensor and set the timing at .081 BTDC and it fired up so far without any kick. The owner will be happy to hear about that. I'm glad it had nothing to do with the compression release, but the possibilities were there.
Again....thanks to all who replied.
Much appreciated.

snoman
 
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