G'Day Guys, apologies in advance if there's a million answers for my question in the FAQ's, I did check, but couldn't find the answer.
First off, a little background. I bought my 1986 Interstate with a ruined engine (PO didn't change the oil in ten years, and maybe 50,000 miles) so I bought a good used engine with 27000 miles from a wrecker in Michigan, and installed it over the Christmas break, using the original engine's carbs and starter. In hindsight, I probably should have cleaned the carbs, which have done 97000 miles, but there you go, I'm not the brightest bulb in the beer fridge..........
Anyway, the engine's in, everything is hooked up, and it runs sweet. I was away from home for the last 2 weeks, so when I got home on Friday, I decided that a Saturday ride was on the cards. Saturday was a great day, the bike started on the third press of the button, and I did a 160 mile ride with several stops and starts (gas, food, beer....) without any issues whatsoever.
This morning, I went to start it to move it out of the garage, and it wouldn't start at all. The battery was fully charged, the engine cranked fine, my killswitch was in the "on" position, I could see that my fuel pump was pumping, (clear fuel lines and new clear filter) and I pulled a plug and earthed it on the rocker cover, and it had lots of spark.
Occasionally, it would repay my efforts with a massive, ear splitting backfire, which was really cool, but frightened my neighbours, who have recently emigrated from somewhere in the Middle East, and apparently don't like loud noises.......
I scratched my head, walked around it a few times, then removed #3 spark plug (RHS closest to brake pedal) attached the cap, hit the button and it produced a lovely fat spark, but coincidentally, the engine started, and happily ran on the remaining 3 cylinders? Weird! I reinstalled the plug, and the bike ran great again. I had other stuff to do, so I didn't go for a ride.
Now I'm wondering if it's maybe a bad earth? Keep in mind that I really have no clue, but I'm wondering if the reason why the engine has fired up when I've earthed a plug to the engine (this is the second time this has happened, BTW) is that there needs to be a better earth betwixt the battery negative terminal, and the engine, and the coils, and the engine? Or am I barking up a completely inappropriate tree?
Thanks in advance for any suggestions guys! Cheers, Terry. :?