Today's progress on resurrecting the 81 GL1100

[chuck c]

Today I finished the fuel delivery system (sender, filter, all new lines). Gave it an oil change. Fixed a few electrical gremlins. New plugs. Put fresh gas in, gave it a a shot of starting fluid, said a small prayer, and hit the button.

:yahoo:
Quickly got a carb overflow dripping gas on the exhaust and making a lot of smoke. I injected some carb cleaner straight into the fuel line, gave the carbs a few whacks, and fired it again. This time we spotted exhaust leaks at the flanges. Tightened them all. Started again. Each time gets a little easier and runs smoother but it still has a scary knock. I don't think it's a bearing. I think one cylinder may not be firing correctly or at all. The exhaust has a little smoke but it's less as it runs.

I hope sitting overnight with clean gas with a touch of Sea Foam helps clear it out. It would be fantastic to not have to rebuild or replace the carbs right away. I am seeing a lot of smoke from the headers right where they go under the frame. It might be burning off old crud or something new is leaking onto it. I'll used some Brake Clean to clean the area and see if that helps. I'll try to get some video tomorrow. The important thing is
IT'S ALIVE!

 

[slabghost]

Congrats!

 

[backlander]

Yep, it's a good feeling to get one to fire off.

 

[backyardtrouble]

your knocking could be from the carbs not being in sync..and running at a low RPM...look and see if it is running at least 850 rpms to 1000...if it is still knocking...it could be a sparkplug not firing right, not enough gas delivery to that cylinder, or the carbs out of sync...if all this is good...you got other problems.

 

[Ansimp]

If you have access to a infrared thermometer it makes it easy to diagnose which cylinder is weak or not firing. You can also use the "quick touch" method and feel the actual header temps.

 

[Steve83]

Woo-hoo! Congrats on the big revival!! It will knock from the primary chain if there is a misfire at low RPM - hopefully it will clear itself up in time.

 

[chuck c]

It won't run at all under about 1500 but it smooths out at 3000. The head temp check is a great tip. I should be able to find a way to check them maybe using the wife's kitchen thermometer. I can check they are all sparking with a timing light. My bet on the cause is a carb not delivering and with some good luck that might clear out by itself with some help from Sea Foam and injector cleaner. I just got an idea. I could put a tee in the fuel line and rig a way to slowly inject cleaner while it's running. Heck, I could just inject it into the line with a syringe. A spare piece of line, of course. MAN it would be great to not have to rebuild the carbs to get it on the road!

 

[chuck c]

I just spotted something in the manual that might be important. It says a blocked tank vent could cause rough running. When I've opened the tank after it's been closed for a while the cap literally pops off like the tank has a couple of PSI in it. The first time I took the sender out I didn't take the cap off first and it blew a good 2" off! The tank vent must be clogged. It may not be the cause of the misfire but it still needs to be cleared. Where is the darned thing?

 

[joedrum]

you dont want to much do you LOL ... you might get lucky but ...id make plans to to go through ignition and carbs as it useally both that cause this condittion ... if i were you id use aft instead of seafoam .. it will distroy the carbs if it ever sits in them

 

[chuck c]

aft?

 

[joedrum]

automatic transmission fluid ...sorry ... 5-6 oz per tank ... it actually good on the rubber parts and cleans without destroying...i like to use it all the time nothing keeps a motor cleaner with absolulutly no discounts ...it will maybe smoke some at first till it gets things cleaned up ... but i think your in for some work here

 

[zman]

chuck c » Sat Apr 19, 2014 5:10 am[/url]":1rfs77gp]
I just spotted something in the manual that might be important. It says a blocked tank vent could cause rough running. When I've opened the tank after it's been closed for a while the cap literally pops off like the tank has a couple of PSI in it. The first time I took the sender out I didn't take the cap off first and it blew a good 2" off! The tank vent must be clogged. It may not be the cause of the misfire but it still needs to be cleared. Where is the darned thing?

By the way, the cap is designed to let air in not out, allthough many people drill them or punch out a hole it is not nessisary unless it is not letting air into the tank.

 

[Steve83]

+1 If the cap vent is plugged, there will be a slight vacuum in the tank after running, and could cause fuel starvation. A little pressure in the tank is normal from evaporating gas and warming temperature. Make sure you close the petcock when not running, or this pressure could flood the engine with gas if a carb float valve leaks.

 

[joedrum]

thet useally stops it at higher rpm and total stopage ... not just run bad at low rpm

 

[charles franz]

As info, Use an old spray bottle to squirt water on the header pipe, if it steams that cylinder is working, an if not that could be the culprit, Hope this helps, Charlie in NC

 

[dan filipi]

charles franz » Sat Apr 19, 2014 9:34 am[/url]":t1553mn8]
As info, Use an old spray bottle to squirt water on the header pipe, if it steams that cylinder is working, an if not that could be the culprit, Hope this helps, Charlie in NC

I find this method to be more accurate than a temp gun. Mine at least.

 

[Ansimp]

dan filipi » Sun Apr 20, 2014 8:56 am[/url]":ixobkcho]

charles franz » Sat Apr 19, 2014 9:34 am[/url]":ixobkcho]
As info, Use an old spray bottle to squirt water on the header pipe, if it steams that cylinder is working, an if not that could be the culprit, Hope this helps, Charlie in NC

I find this method to be more accurate than a temp gun. Mine at least.

With a temp gun you can see minor differences in temperature for final tuning and jetting :yes:

 

[dan filipi]

Ansimp » Sat Apr 19, 2014 6:03 pm[/url]":1xzytb9m]

dan filipi » Sun Apr 20, 2014 8:56 am[/url]":1xzytb9m]

charles franz » Sat Apr 19, 2014 9:34 am[/url]":1xzytb9m]
As info, Use an old spray bottle to squirt water on the header pipe, if it steams that cylinder is working, an if not that could be the culprit, Hope this helps, Charlie in NC

I find this method to be more accurate than a temp gun. Mine at least.

With a temp gun you can see minor differences in temperature for final tuning and jetting :yes:

Really all you need is to see if the header is around the same temp.
There isn't any final tuning or jetting that can be done on the stock carbs anyhow.