84 1200 runs fine cold and dies when warm

Information and questions on GL1200 Goldwings (1984-1987)
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Posts: 8
Joined: Sat Oct 08, 2011 10:20 am
Location: Bellevue, NE
Motorcycle: 1984 GL1200A Aspencade
1977 GL1000
1986 Suzuki GS550L

84 1200 runs fine cold and dies when warm

Post by DRDIESEL77 » Wed Jun 19, 2013 8:54 pm

Hi I have a 84 asspy that I am having running problems with. After I had got the bike back together this spring after getting it painted, I was doing a shake down ride thru my neighborhood. I had also replaced the stator this winter, main reason for the shake down ride. I put 9 miles on the bile and when making the last turn to head home the bike died. It would restart and rev up just fine but when I went to move forward, the bike would die. It did this 5 times before I finally go it to stay running by revving up to 4500 and slipping the clutch to get it to move. When I got it home it would rev up fine and move just fine in the driveway. A couple days later I had the bike running and it just died on me, I started doing some checks and found that the fuel pump quit. Did the Prelude pump conversion and got the bike to start up again but it only ran for a few seconds before it died and wouldn't restart. After several frustrating days and complete ignition system checks and even talking to a Honda shop for about an hour, we decided that the pulsed generator was bad. Changed the generator and the engine started and ran fine. Took it out on a trip around the block and it died before I made it 5 blocks from the house. It would start up fine as long as the throttle was held wide open but would not run if I backed off the throttle. When I had the throttle wide open, it would only run at about 1100 rpm's. Pulled off the street into a parking lot and started doing some checks. Fuel pump operated just fine and with the suction side unhooked from the tank, bike would run the same. hooked the pump back to the tank and I could watch the fuel refill the lines to the carbs and start back up, but wouldn't idle or run less than full throttle and only get 1100 rpm. thought maybe the filter was plugged, so I ran a bypass line straight from pump to tank bypassing filter, but no change. There were a couple times that I could get the bike top rev up and hold it at 3200 plus rpm, but when I went to move the bike, it would die and not run above 1100 rpms at wide open. I noticed that it would run higher rpms after it cooled down slightly but when the rpms dropped below 2600 rpms the bike would die and wouldn't rev up. I decided that I would let the bike cool down considerably and try it once it was cold. Two hours later, when I tried the bike I was able to run and drive the bike home without problems. Haven't had much time to work on the bike but I noticed that if I warm up the bike and try to ride it in the driveway it has the same problems.

I did notice that when I removed the gas cap, I heard the whoosh sound, but I checked the gas and it was pretty low. I got some gas and out in the tank and left the cap loose on the tank when it was still having problems. When I changed the pulse generator, I removed the tank and rear tire and fenders and was able to reach everything somewhat easier than removing the engine. it was a little tight because of the swing arm but not terrible. I do not remember seeing a tank vent line coming off the tank as I have read in several other postings on this forum.

I did have the carbs cleaned this past winter and I noticed that even tough the engine is more responsive, the choke doesn't do anything and now I am thinking the carbs are the problem. Last year I had to do a frame swap after I got the bike because of some wreck damage to the original frame and front cowl. there was no damage to the engine. After I got the swap done I was able to ride over a thousand miles with the carbs dirty, choke slightly on, till the stator quit on me a hundred miles from home.

I need thoughts about what could be wrong with my bike because I have nice weather but I am afraid to ride cause I don't want to have to walk home after the bike strands me. I have rechecked the ignition system and I still have good spark even after the engine dies and wont run unless wide open at 1100 rpms. Please help I miss ridding with no worries. Thanks for the help.

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Posts: 8356
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: 84 1200 runs fine cold and dies when warm

Post by virgilmobile » Thu Jun 20, 2013 3:57 pm

Spark,compression and gas....Process elimination....
Spark confirmed good....
When it runs,it runs....compression OK

Only thing left is fuel starvation.....When it won't run..Crack open the carb drain screws...see if there is about a shot glass of gas in each carb....
If there is,the jets are probably plugged up....

Posts: 5
Joined: Fri Mar 20, 2015 3:39 am
Location: Coos Bay, Oregon
Motorcycle: 1984 GL1200 Aspencade

Re: 84 1200 runs fine cold and dies when warm

Post by detroit » Sun Apr 05, 2015 7:20 pm

I JUST pulled the bike in, GL1200, and after cussin up a storm,and probably gonna hear it from the mrs when I go in, typed the same problem in and came hear, like I always do whenI I have an issue w/the bike. For the last TWO weeks, and more of those days than not have been nice out here on the west coast, I have been screwin w/ this bike, doing everything this poor man has done to his, to no avail. Im ready, for a drink for starters, to pull my friggin hair out.(Surprised I still have some) I'm lost. I dont know what else to do. Its raining here on the Oregon coast right now, but the sun will shine here again, and when it does I'd like to be ready for it. There cant be many other places to ride that are more breathtaking than here to ride. Any help will do. Thx.

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Posts: 918
Joined: Sat Jul 05, 2014 11:53 am
Location: Courtland, Va.
Motorcycle: 1984 GL1200 Interstate
1981 GL1100 Interstate

Re: 84 1200 runs fine cold and dies when warm

Post by HawkeyeGL1200 » Sun Apr 05, 2015 8:27 pm

I would check to be sure your fuel pump is getting DC current to it all the time the engine is running. I just went through something similar. It appeared my fuel pump was bad, and it turned out I had a broken wire in the circuit. Once I sorted out the wiring issue, the bike ran and has run fine since.

I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

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