Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Sign in to follow this  
Tired

No spark when plug installed

Recommended Posts

MarkH
I'm not quite sure how you are checking for spark, but if you have the plug screwed into the head and are holding the plug wire off and trying to get it to jump to the top of the spark plug it now has to jump the plug gap and the gap between the wire and the top of the plug.If this is how you are doing it how close are you holding it to the plug end? Just a thought. good luck. Mark

Share this post


Link to post
Share on other sites
Tired
I'm useing a spark tester connected to the block on one end and the spark plug wire on the other end. While cranking the engine with no spark plug in the head there is good spark, But when I screw a spark plug into the head with out hooking the wire to it I lose the spark. I got a chance to ask my brother about it and he thinks that the fly wheel key may partially be sheared along with enough play in the crank shaft to mess up the armature air gap with the compression force on the crankshaft. This all started happening when my wife went to mow grass today, Started fine then she gave it full throttle and it killed. Does that sound possible?? Thanks, Scott

Share this post


Link to post
Share on other sites
Tired
I have a 16hp briggs that has good spark only when there is no spark plug in the cylinder head. As soon as I install a plug without hooking the wire to it I lose spark. The engine cranking speed is is good with or without the plug installed. It dosent make sense to me, any help would be appreciated, Scott

Share this post


Link to post
Share on other sites
Kent
How are you confirming spark when there is no plug in the head, and then how are you checking for spark when there is a plug installed? I'm assuming you're jumping an arc to ground from the spark plug lead to the block. If so, consider that you might be positioning the plug wire differently in the two scenarios, and if there is a break in the plug wire, this could account for it. Interesting symptoms....

Share this post


Link to post
Share on other sites
BJennings
I just recently had a spark problem with my Big Ten. It was running fine one day then suddenly wouldn't start. I could tell it was firing, but it sounded like it was out of time. It ended up being the key on the flywheel. I happened to have one at the house already, changed it out, and it fired right up!

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

×