Update on the GL1100 project that got dropped in my lap!

[ddragon63]

So I've been running this hunk of Honda in my Garage the last couple nights working some seafoam thru the fuel system. There's no throttle lock so a little black tape to hold the throttle about 4k worked just fine.

Got home from work today and the roads were dry and rain looked a ways off so I drug it out and beat on it around the back roads out here. Run's better but still has a flutter issue under wide open throttle. Seemed to get worse the longer I rode it. Started to rain so I headed back to the house. Parked it in the garage and pulled plugs. They didn't look too bad. Now here's my possible AH HA Moment....

I opened the fuel door, to pull the cap to verify fuel level... as soon as I twisted the cap out came a giant WOOOOSH!!!!

Could it really be as simple as a bad vent in the gas cap! Cuz that would make sense! The fuel pump only makes 2 psi (yes that's factory spec) if the tank is building vacuum that fuel pump will have a hell of a time pulling under a load!

Gonna try and ride it tomorrow with the cap loose and see... the idle quality sure is better with the cap off. Might have to drill a hole in the cap to vent it and then tell my buddy some big story about how I had to remove all his carbs and blah, blah, blah!

[DGXSER]

Yep, it could be that simple. Seen more than a few folks struggle with that same issue on an XS11. I ran into it on my Craftsman lawn tractor.

Before you go drilling on the cap, it probable has a vent in it somewhere you can clean.

[ddragon63]

Yep, it could be that simple. Seen more than a few folks struggle with that same issue on an XS11. I ran into it on my Craftsman lawn tractor.

Before you go drilling on the cap, it probable has a vent in it somewhere you can clean.

I just got off a goldwing forum... everything I've read says to soak it solvent, buy a new one, or drill a small hole in the top. Man if its this simple I'm gonna kick MYSELF in the nuts

[Joab]

I really want to know how this story ends. Just saying.

[DGXSER]

I want to see him kick himself in the nuts!!! Talk about a contourtionist!!

[ddragon63]

I'll test my theory tonight by not tightening the cap and going for a ride. Outside of carb dismantle I've been thru the whole fuel system. The more I think about the cap the more it makes sense. If you let it sit for a few minutes after riding it it is a pain to restart. Like its flooded. But once it starts it don't smell flooded. I'll get back to you with my finding. Why do I always over look the simple things?!

[ddragon63]

today's findings

OK.... so I got home. nice afternoon! owner of the bike told me to knock a hole in the cap so I did. rode it down to the gas station. Turns out the fuel gauge is off by about 2 gallons! it read empty and it still had 2 gallons in it. So i topped it off with 76's finest 92 octane and dumped more seamfoam in her. then I headed off... put 34 miles on it.

Does it run better with the gas tank not vacuuming? Yes
Did it fix the issue? Not really

It runs 100% better than when I rode it yesterday. But more than 3/4 throttle She still gets pissy!

So I did my old race car trick on the way home. I passed the old fire station by my house and hammered down! @ 60 mph I shut the bike off put it in neutral and coasted into the garage. Pulled all 4 plugs and this is what they look like.



we haven't sync'd the carbs yet... it runs great @ a cruise. Could # 4 just be so out of sync that it causes it to be dirty and piss off the rest of the program?

[crazy steve]

The two outside plugs look about right. The upper inside looks lean, lower rich. If those two cylinders share a coil, I'd look at that; check to see if the plugs caps are both good (assuming these use the same 5K ohm resistance caps). If that checks out good, then I'd say it's time to clean the carbs.... I don't think a simple sync will cure this.

[ddragon63]

The two outside plugs look about right. The upper inside looks lean, lower rich. If those two cylinders share a coil, I'd look at that; check to see if the plugs caps are both good (assuming these use the same 5K ohm resistance caps). If that checks out good, then I'd say it's time to clean the carbs.... I don't think a simple sync will cure this.

the 2 lowers are 2 and 4 and the uppers are 1 and 3.... 1 and 4 share a coil and 2 and 3 share a coil.... Good thought Steve. I'll check them out today. the Manual is pretty vague on how to check the coils other than "replace with known good coils" or "If 1 coil is suspect swap the 2 coils and see if problem follows individual coil"

So I'll do a little digging and see what I come up with. but that would make sence as 1 is a little lean (it also came out a little wet ) and 4 is rich as they share a coil

[ddragon63]

ok now I'm confused. The repair manual says 1 & 4 are on same coil but now I'm reading online that 1 & 2 are on same coil... guess a tear down and inspection are in order.... and I've read how to test them, I think. and how to test the boots... Man I'm gonna quit taking in "friends" projects. I can't wait for Him to come over tomorrow so I can chain him to his Honda!

[ddragon63]

OK.... I looked up the coil specs and went @ it with my multi-meter... My findings, #1&2 coil is bad. I had a hell of a time getting a good reading on it. as I moved #2 wire around I would get different readings or no reading @ all. So I took all the caps off the test the wires straight up. Same problem. caps are good. Now on a hunch I put it all back togther and fired it. Got it idling and unplugged #1 nothing changed. its running on 3 cylinders.

If you look @ the plugs below the go from left to right.... top #1 and #3 bottom #2 and #4. I was paying more attention to how dark #4 was and not how clean and wet #1 was. Got if figured out now. This old dog needs coils. Thanks for the idea Steve!