Help poor low speed performance


Information and questions on GL1500 Goldwings (1988-2000)
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Wrecker_0
Posts: 1
Joined: Sun Jan 13, 2013 2:16 pm
Location: Lagrange Texas
Motorcycle: 1989goldwing 1500

Help poor low speed performance

Postby Wrecker_0 » Sun Mar 10, 2013 10:54 am



Hello
I have a 1989 1500 that exhibits poor low speed performance like there were a problem in low speed fuel circuits in carbs. I have allready rebuilt them. My level of knowledge I am an ASE master auto
tech with no bike experience Engine starts easily but obviously does not run smoothly when warming up. It also exhibits surging I installed new plugs to no avail. It performs well above say 2000 but is a real pain to get rolling It requires constant throttle manipulation to get rolling. I need some ideas



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virgilmobile
Posts: 7655
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: Help poor low speed performance

Postby virgilmobile » Sun Mar 10, 2013 12:56 pm

I to had a boat load of problems with my 88 with low speed performance.
My cures.....
Increase low speed jets from #55 to #60
Replaced the accelerator diaphragm and plugged all the bypass ports.
Replaced the "O" rings on the accelerator coupler tube.
Adjusted the accelerator actuator linkage to a minus 0.10"
Replaced every rubber hose that has a sharp 90° bend...there are 7 of them.Including the one under the Carb rubber mat.
synced the carbs and adjusted the idle mix screws down to near 1.75 turns out.
I can now roll in any gear at 600 rpm, crack the throttle and smoothly accelerate to red line.
No more bucking.
I can idle around a corner at 20 mph in 5th gear and open the throttle with no growling and pull back to the highway speed.
I can also let my clutch out at a idle without killing the engine and just crack the throttle for a smooth acceleration.
My gas mileage dropped about 3 mpg..... I average 35 MPG on a 'round town and country ' drive of 100 miles.
My 1500 also takes a minute it two to "warm up" before I can let off the choke.
Well it is a 88 model.....not a multiport fuel injected computer controlled car, so I suspect it's normal.

bustedwing
Posts: 1052
Joined: Wed Nov 30, 2011 4:17 pm
Location: Hermansville, Mich
Motorcycle: 1990 Gold wing Trike
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Re: Help poor low speed performance

Postby bustedwing » Sun Mar 10, 2013 1:35 pm

As Virgil stated one of the things to check would be the rubber hoses. From your description it sounds like a vacuum leak and with hoses that old it can be hard to find. I have done the same thing on my 90, blanket change all vacuum and water hoses while I was at it. Yes it's a nightmare, but when you are done you no longer have to worry about them. ?
Proud member Patriot Guard

amsoilguy
Posts: 117
Joined: Thu Jul 05, 2012 3:33 pm
Location: Boise, Idaho
Motorcycle: 1988 GL1500

Re: Help poor low speed performance

Postby amsoilguy » Mon Mar 11, 2013 11:03 am

I have the same issues with my '88 I bought last year and have yet to dig into it.

Virgil, I know you've done a lot of work correcting your issues and have read several of your posts, thank you for that. Have you consolidated any of your procedures that people could click to or is better just to do a search here on the board? I have NO bike mechanical experience, just shade tree work on my old Chevy trucks. I have picked up both Clymer and Honda shop manuals.
Allan

'88 GL1500

User avatar
virgilmobile
Posts: 7655
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: Help poor low speed performance

Postby virgilmobile » Mon Mar 11, 2013 12:46 pm

This bike isn't any different than a truck....It takes gas to run it the same way the bike does.....Fuel mixture,compression and spark...it's all the same..

I did not consolidate the info for a reason...
My EXACT symptoms were not the same as many others...I identified 3 different problem areas.
Idle...Of idle and low speed mixture(verified by using the "choke")...

Each bike is or can be a little different....Mine just happen to be OEM with no mods done by a previous owner or any authorized factory change.......Honda Goldwing GL1500 1988 Low speed driveability improvement-55A9B

My mods were done one step at a time to resolve each problem area that I had.
I removed the carbs 5 times for alterations...You know..try this and see what it does..

Any mod...eg.4 degree trigger wheel,re-jetting the carb(factory),ignition and carb control module change(factory) alters the fuel mixture and control systems.

Each mod I did to mine was to improve on the original design problems.
Some of the mods by the factory and after market parts seem to fix the problems also,but those parts were not available to me.

Sooooo....Take all the information on each mod and see what applies to your specific needs....

There were just a few changes to my 88...
I had a off-idle bucking and lagging engine from 1000-1500 rpm.It idled poorly.
Besides the vacuum lines(poor idle),my main "cure" was a slight increase in the low speed jet size,lifting the metering needle and getting the accelerator pump to squirt as soon as I cracked the throttle.
Obviously,a carb sync and idle down adjustments were done afterwards.

amsoilguy
Posts: 117
Joined: Thu Jul 05, 2012 3:33 pm
Location: Boise, Idaho
Motorcycle: 1988 GL1500

Re: Help poor low speed performance

Postby amsoilguy » Mon Mar 11, 2013 2:02 pm

I understand...thanks!


Allan

'88 GL1500


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