Join Date: Jun 2019
Location: Statesville, NC
1981 GL1100 will not run
Hi everyone. This is my first post and I'm hoping for lots of help.
I've had a lot of bikes and British cars through the years and consider myself a pretty good mechanic, but my recent purchase of an 81 GL1100 that had been sitting for a long time has me stumped. Since it had been sitting, I knew from experience I had to go through the carbs to get it going. I cleaned the main jets, needles, seats, and everything else thoroughly, along with setting the float levels. I put everything back together and the bike ran, but would not idle. I took the carbs back off and extracted the idle jets per the forums here, or possibly from another source. They were clogged and I had to use a tiny drill bit to clear the main hole and fine wire to clear the other holes. I put it back together, again being very careful everything was clean, and adjusted the floats correctly. The bike will now barely start if I use about half throttle and then will only just chug, chug, chug, chug after it finally does kick over. If you let off the throttle, the bike immediately dies. I know it's getting fuel, it just doesn't seem it has the spark to get going. All four intake tubes are very cold to the touch when it's trying to run. I've been through the carbs four times with the same result each time. The third time I changed floats, needles, seats. The bike still will not run.
These are the things I've done to try to get the bike running.
New NGK spark plugs. Gap is correct
Have good spark on all four cylinders
All plugs have a dark sooty appearance, but are not wet. I know that indicates a rich condition, but I've seen bikes and cars fire off with worse looking plugs
Compression is well within tolerance at about 150 lbs on each cylinder
Adjusted valves. Clearances are correct. Made absolutely sure I was at TDC on cylinder #1 before adjusting. Engine was cold.
Original coils were not giving resistance readings that were in tolerance with the manual. I swapped the old coils for a different set from an '81 that are in spec, ohms wise.
Plug wires are not crossed. Believe me, I've checked.
Voltage at the battery is about 11.2 when starter is engaged
Fuel delivery is good. All carbs have fuel. No excess fuel in the plenum
Pulse coil resistance is within tolerance at 530 ohms
Both spark units have been tested per the manual and check out fine
I'm not usually stumped with mechanical things, but this bike has done it. Can anyone offer suggestions for something I must be missing?