No power in 4th and overdrive


Information and questions on GL1500 Goldwings (1988-2000)
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Heavysled
Posts: 3
Joined: Fri May 01, 2015 8:00 am
Location: Unity,Saskatchewan.Canada
Motorcycle: 2002 GL1800
1989 GL1500
1985 GL1200A

No power in 4th and overdrive

Postby Heavysled » Tue Jul 21, 2015 10:27 am



Hi
I am having trouble with a 1988 Goldwing with 8000 miles on it.
I can redline in all gears exept 4th and overdrive.
I have done Vacume checks,ground line to computer works in both top gears OD light comes on ,cruise system works , changed fuel pump.
I am now thinking the computer may be at fault. 88 has a different computer than the 90 bike that I have one from.
Any ideas would be helpful..
:D



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virgilmobile
Posts: 7663
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: No power in 4th and overdrive

Postby virgilmobile » Tue Jul 21, 2015 11:15 am

Just for fun,disconnect the 4th and 5th gear selector wires at the front of the bike.Those 2 wires do tie into the ignition module and possibly the carb control module.Unhooking them would make the bike think you never left 3rd and not adjust the timing.
See if it runs out.If it does,then reconnect it back and just disconnect those wires from the ignition module.Same test.
This would be to see if the problem is related to fuel delivery(not enough fuel to run a heavy load),ignition module timing change or carb module control.
I'd have to verify the carb module is triggered from the gear selector.Not positive.I do know that it opens and closes electric valves at different RPM ranges tho.
You may be able to just unplug the selector switch..Just have to start it with the clutch lever pulled in.No neutral indicator.
If all fails,do verify that the slides do move when the engine is revved up.If one sticks,it will go pretty good on a light load and fall flat under heavy load cause it ain't breathing right.

Heavysled
Posts: 3
Joined: Fri May 01, 2015 8:00 am
Location: Unity,Saskatchewan.Canada
Motorcycle: 2002 GL1800
1989 GL1500
1985 GL1200A

Re: No power in 4th and overdrive

Postby Heavysled » Tue Jul 21, 2015 3:52 pm

Thanks for the idea sounds plausible I will try it and post back. :D

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virgilmobile
Posts: 7663
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: No power in 4th and overdrive

Postby virgilmobile » Tue Jul 21, 2015 9:24 pm

I'm interested as I also run a 88..Mine has the OEM module in it...It was never upgraded for the factory recall drivability issue...
And yes,the 88/89 were different than the rest...Ignition,carb control,and reverse circuits ...just to mention the ones I know for sure.
I thought I read somewhere that the ignition has a preset range that it operates in until it gets a ground signal from 4th or 5th gear...then the computer "adjusts" the timing for cruising.
There is no mechanical advance mechanism in the timing like the 1100 engine...BUT...there is a vacuum sensor in the ignition module..
Have you removed that small vacuum line at both ends and looked at its condition?
I think it's behind the intake runner on the right rear and enters the module on the bottom right as you look at it...

Heavysled
Posts: 3
Joined: Fri May 01, 2015 8:00 am
Location: Unity,Saskatchewan.Canada
Motorcycle: 2002 GL1800
1989 GL1500
1985 GL1200A

Re: No power in 4th and overdrive

Postby Heavysled » Wed Jul 22, 2015 5:58 pm

Hi,
Well I have tried the disconnect to the computer with no avail and have been checking other things. I would like know if anybody knows what the vacum valve at the front by the ignition module is for.
I have only a 98 manual for a 1500. This valve was disconnected when I got the bike and assumed that it was part of the service upgrade that was performed on the 88 bikes. Mine has the x stamped in the frame. Does anyone know if this valve I supposed to be disconnected?
All the diagrams that I have been able to find on the Internet so far do not show where they hookup .

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Snowmoer
Posts: 51
Joined: Fri Jan 25, 2013 12:23 pm
Location: Yucca Valley, California
Motorcycle: 2012 GL 1800
1988 GL 1500
1977 GL 1000
1988 NX 650

Re: No power in 4th and overdrive

Postby Snowmoer » Thu Jul 23, 2015 1:59 pm

My 88 was the same way, but would also stumble some in 3rd. I found that the vacuum line from the warm air valve on the snorkel that goes to the air box was broken. It goes from the valve to the left intake behind the middle cylinder. Replaced it, and ran like a champ. Just something else to check

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robb
Posts: 1040
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Location: Lexington, North Carolina
Motorcycle: 1989 Honda GL1500 Aspencade

Re: No power in 4th and overdrive

Postby robb » Thu Jul 23, 2015 3:52 pm

When I had a problem like that it was broken vacuum lines at 90 degree bends by middle cylinder spark plugs. Corrected and it has ran great since.

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virgilmobile
Posts: 7663
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: No power in 4th and overdrive

Postby virgilmobile » Fri Jul 24, 2015 3:08 pm

This valve was disconnected when I got the bike and assumed that it was part of the service upgrade that was performed on the 88
All the diagrams that I have been able to find on the Internet so far do not show where they hookup
.

To my knowledge,all the 1500's require this vacuum line attached between the module and the right inside manifold.




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