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SmilinSam

Ignition problems, Need a direction to go

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SmilinSam
I have never had difficulty with putting Battery ignition on a briggs before but this time it is giving me fits. It will run at idle and half throttle just fine but when you try to run it faster it likes to start missing real bad. I have tried different coils, points, condensers, plugs and lead wires. No difference. If you real gradually increase the speed it sometimes will run buit miss intermittently but if you increase the throttle quickly, forget it- it wont run until you back it off to half throttle. Also, adjusting the carb makes no difference either, and I have gone through the carb twice. Disassembly and parts changing is my specialty- not diagnostics. Point me in a direction please, because I'm hopelessly lost. Thanks, Sam

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BEB
Hi Sam, Just a guess here. Have you checked for a bad head gasget? If not try spraying wd-40 while engine is running around head gasget area and also spray it around the carb gasgets. Just a thought but you probably already have done this. Also what happens if you try to run the choke after part way open then increase the gas? Take care, >>-.happyjack<-<<

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SmilinSam
Its a fresh rebuild with a new head gasket and carb gaskets. I tried the manipulating the mixture with the choke thinking I might have a air leak somewhere, but that was not the case. I have run it with the cover off the points and watched the spark and lack thereof coincide with the missing. I cant figure out what would cause the spark to fail at higher engine speeds????????????????????????????????????

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Al
Hi, If this is a new rebuild sheck the valve guides for adequate clearance.. If you have drag in the guides, the springs may not pull them shut at high speed. Spraying some penetrating oil in the carb when it is running at max may free it up, If that lets it rev up alittle more, ikt may be a clue. Good luck, Al

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Guest
if you put a carb kit in it theres a chance that the body that your high speed needle screws in to is installed backwards and that would keep your high speed needle from going in as far as it should.Screw your high speed needle out of carb and remove the threaded body out of carb that needle threads into.The part the needle threads into has inside threads in one end and smooth inside other end .The smooth end is the end the needle goes into.I hope you understand my rambling. EMAC

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SmilinSam
I really dont think it is a carb or valve problem, I have checked all that and besides it will run at full speed but not smooth for any length of time without missing I did get about ten minutes of smooth full speed working it with the tiller the day before yesterday before it started having its fits. That was after I replaced the coil and condenser with another one. Everything seems to be pointing to it being an elecrtical thing. How about timing as in point gap? does any of these symptoms coincide with points set to close or too far?

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Scoop
Hello Sam, I had a problem that sounds a lot like yours on my 916H, after racking my brains and knuckles for a couple of weeks, turns out it was a loose wire on the ammeter. Hope this helps. Tom

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dlcentral
Hey Sam, 3 things 1]-change the spark plug 2]-use a KOHLER coil car coils won't work. 3]- use a plug wire with WIRE in it not graphite string like cars use. Try those things.

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SmilinSam
Been There too. I took all the components right off a Kohler and used. I suppose, the way my lucks been going that the coil off that could be bad too?? I might have to wait for some more parts and try again. I was told last night by a couple of people here thjat lack of spark at high engine speed points to a bad coil??? I'lll keep trying. It has to be something simple. Smilin'Sam

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carter
Sam, For what it is worth I'm with Steve on setting the points at speed. If it works the difference might only be one or two thousands of an inch. The point gap is actually the timing on the battery conversion. The plunger thought is a good one too. I had a Honda drive me nuts until I replaced a cam bearing that was constantly ghanging the point setting.

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stevejj56
I've had trouble like this. On two tractors,i had to adjust the points while the tractor is running full speed,missing bad,and that pretty much cured the problem. I would check the point gap then and it would be less than .020 . I've never had this kind of problem with a Kohler. So it still baffles me why their like this. I completely rebuilt a 12 hp briggs for a B-12 and it has a miss at high rpm. I even bought a NEW carb and it didn't help. I talked to a guy that has worked on these tractors for a long time, he said my problem is probibly the points plunger is wore on one side. When its running, it turns and the points change. I havent had time to replace it yet to see if it is the trouble. Steve

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Eddie
You should put a dwell meter on your points and see what your reading is, or your coil might be beaking up at a high idle. If I were you I would put a knew coil in and see unless your coil is knew. Just check for loose conections.

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Guest
Sam I am with Steve also. I thought that I was the only one having to adjust my point with the engine running. But this is something I used to do when the distributor was worn out on some cars way back when. I was really able to fine tune them even better then with the dwell meter hooked up it just worked better. >>->happyjack<-<<

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SmilinSam
And Steve indeed has the winning advice, Thanks guys! I tried setting the points while running and I got it so it runs great. I'll have to investigate the possiblity of a worn plunger later, for now I am back in business. Thanks a million, Sam

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