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Spark Plug Gap?

9

904

Big Wheel
Hi y'all, I'm a long time COG member but haven't been active for a few years. I've been getting back into riding this year and the Connie started up just fine! Just needed a battery, air up the tires and shocks, and she was good to go. Oil was changed just before she was parked, tires were near new, fuel tank was full of good Amoco 93 with fuel stabilizer added. I started on another project bike a few days ago. I have a '87 ZL1000 Eliminator which had thrown a rod a few years ago. I had purchased a used Concours engine to put in it because the Eliminator engines are really hard to find. The main differences are the oil pan (no cooler on the Eli, but there is an oil temp switch), the air reed valves on top of the valve cover, gear ratios (both transmission internal ratios and final drive), and lack of the balancer shaft on the Eli. I'm in the process of swapping parts over (front bevel gears, oil pan) and preparing the replacement engine (adjusting valves, timing chain tensioner). I found that the gap was closed up on one of the spark plugs that I pulled out of the replacement engine. Anybody ever had a spark plug gap closed up on them? What was the prognosis? In my web searching I've found some examples that turned out to be broken ring lands. Just wondering if I should pull the head instead of putting the engine in the bike. Any way to see down in the cylinder without pulling the head? Thanks, Brian COG # 904
 
Sounds to me like there could be some sort of mechanical/carbon interference or the PO dropped the spark plug while installing and didn't recheck the gap before installing. Don't know if you can use a 6" (or 12")digital caliper for a TDC tool but that would be my first attempt to check all four cylinders and compare. Whilst in the checking mode why not roll each cylinder up on TDC and do a leak down test and if the results show a need pull the head. Don't forget to put the tranny in 6th or hold the crank from moving off of TDC or you will get an erroneous reading. Just some thoughts and more ideas from others to follow..
 
Found a local shop with a borescope. Basically a flexible shaft with fiber optics that you can stick in the spark plug hole. Hopefully nothing's broken. I might do the leakdown test too, just never really thought aboout it.
 
simple things first. are all the plugs the same #? Years ago helped with a tune up on a flathead ford. It would start and idle just fine, but when we opened it up, the slack in the rods would let the pistons touch the electrodes and close the gap. Just 1 # off was all it took. COG # 8062 AMA # 1084053 ROMA or Scarlet harlot acording to my wife
 
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