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Bob Bauer

K 91 spark problem

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Bob Bauer

So on my k 91 engine when I turn the flywheel by hand I will get a spark and the next couple of turns I get nothing. I put new points in plus checked with the old points and still got the same results. I replaced the wire from the points thinking it might be that but the same thing. I’m in the process of putting it back together so trying to figure out what the problem is. I had spark before tearing it down to replace the valves but now only getting spark about every three turns when turning by hand. I cleaned everything up behind the flywheel for the contacts and new points.any thoughts. Was going to add pictures but can’t figure out how.Thanks 

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953 nut

Did you replace the condenser?  If the condenser lead to the points is disconnected do you get spark?  The condenser you should use is pare number 235786 for a magneto ignition system. 

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Bob Bauer
47 minutes ago, 953 nut said:

Did you replace the condenser?  If the condenser lead to the points is disconnected do you get spark?  The condenser you should use is pare number 235786 for a magneto ignition system. 

When the condenser lead to the points is disconnected no I do not get a spark. When I ordered the points, they sent me a different condenser that I could not use and I could not find the one I needed, but now that you gave me the part number. I will look it up and order one. Thank you for your help. I will try that.

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Gasaholic

One minor thing to bear in mind, especially with cranking by hand, if points are running off the camshaft like most K series, you're only gonna get a spark every other revolution - Unlike lawnmower engines (which are a waste spark system - that is, they'll fire every revolution - once at top of compression and once at top of exhaust, which is wasted spark - K series with points operating off the camshaft fire only at top of compression stroke (Which trips up newbie using common inductive tachometers - with many of those that count RPM based off ignition pulses, you gotta "double" the RPM reading to get a true RPM's, unless the tach has a means to account for it - 4 stroke vs 2 stroke) 

 

So rotating engine by hand, can be difficult to test for a reliable steady spark if you can't get it rolling through multiple revolutions at speed fast enough to generate a spark.... just something to bear in mind. 

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Bob Bauer
7 hours ago, Gasaholic said:

One minor thing to bear in mind, especially with cranking by hand, if points are running off the camshaft like most K series, you're only gonna get a spark every other revolution - Unlike lawnmower engines (which are a waste spark system - that is, they'll fire every revolution - once at top of compression and once at top of exhaust, which is wasted spark - K series with points operating off the camshaft fire only at top of compression stroke (Which trips up newbie using common inductive tachometers - with many of those that count RPM based off ignition pulses, you gotta "double" the RPM reading to get a true RPM's, unless the tach has a means to account for it - 4 stroke vs 2 stroke) 

 

So rotating engine by hand, can be difficult to test for a reliable steady spark if you can't get it rolling through multiple revolutions at speed fast enough to generate a spark.... just something to bear in mind. 

Ok thanks 

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