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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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if you are 1000% sure you're getting into 5th, check the clutch cable and make sure its adjusted correctly. If it is, I'd look into replacing the clutch.
Or maybe the clutch cable.
Lever free play decreases and clutch drag increases with plate wear. Try increasing free play a little.
 

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1982 Honda GL500 Silverwing / Cafe Racer
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Discussion Starter · #22 ·
Thanks Guys , I’m 1000% sure I’m getting 5 different gears , so I will look back at clutch cable next then clutch replacement . I really appreciate all the advice and will be sure to post the solution back when it’s solved so someone else can benefit from it later
 

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1982 Honda GL500 Silverwing / Cafe Racer
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Discussion Starter · #24 ·
And speedometer??
Original?"rebuilt"ebay??....
Gan you compare the speed with a phone GPS app...??
Speedo is a good point - mine is aftermarket and indicating 125-130 KPH when valves start floating at redline.. but have confirmed this top speed ~82mph when riding with a group of friends.
 

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Get a GPS and measure your speed via that -
I suspect the Speedo is OFF (and maybe the tach too) -
As they age the cables become less capable and the internals of the 'clocks' become sticky and (s)low -

I think you will find you are reaching the TON (100mph) and not realizing it ;)
 

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Get a GPS and measure your speed via that -
I suspect the Speedo is OFF (and maybe the tach too) -
As they age the cables become less capable and the internals of the 'clocks' become sticky and (s)low -

I think you will find you are reaching the TON (100mph) and not realizing it ;)
he already confirmed he is hitting 82mph in post #24
 

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'82 GL500 Silverwing (non-interstate)
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For my GL500, the revs are under 8500 At 85 mph. Besides counting the gears, I can tell I am in 5th because the rpm’s (1000’s) drop below the mph. For example, the tach shows ~6,250 rpm at 65 mph.
 

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1982 Honda GL500 Silverwing / Cafe Racer
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Discussion Starter · #31 ·
Get a GPS and measure your speed via that -
I suspect the Speedo is OFF (and maybe the tach too) -
As they age the cables become less capable and the internals of the 'clocks' become sticky and (s)low -

I think you will find you are reaching the TON (100mph) and not realizing it ;)
Absolutely positive about achieved speed , I’ve since reconfirmed this on Sat Nav , also near redline 5th gear safely through the UK’s M25 speed traps without a flash.. keeping up with normal motorway traffic , slow lane also is near 9500 rpm 5th .no signs of clutch slip as much as I can test it either
 

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Or a German import with the horsepower restriction?
 

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Might b worth taking it for a ride getting to 5th...
Then tell us 4000rpm=?MPH
6000rpm=?MPH.
Tho not a diagnosis might rule out a few things....
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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'84 CX650E that is evolving into a GL500
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I can't think of anything other than popping back to 4th gear or the clutch slipping that could cause the RPM to be that high for that speed.
 

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Food for thought, he confirmed his speed was correct, but we don't know if the engine speed his tach gives is correct. He mentioned an aftermarket speedometer. He might also have an aftermarket tach and if mechanical it may not be of the right ratio...
 

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1981 CX500C
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Does anyone know the entire drvetrain gear ratio (from engine to rear wheel) in 4 th gear?

If so, then a calculation should be close either inputing 82 mph to solve for engine speed or go the other way...input engine speed to find the mph.

I tend to side with Bob's comment.....dropping back to 4th or clutch slip. I lean more to clutch slip.

Speed and engine rpm are mechanically related. Apparently, the carbs and ignition will support a redline engine speed. So, not caused by carb or ignition.
 

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GL500 primary drive 2.242:1, 4th gear 1.148:1, final drive ratio3.091:1

130/90 X16 tire has a circumference of (((130/25.4)*0.9*2)+16)*3.14=82.4 inches. 6.87 feet per revolution or 768.6 revolutions per mile. At 82 miles per hour that is about 1050 rpm. The engine would be turning about 8356 rpm.
In 5th gear the engine would be turning about 6775 rpm at 82 MPH. All assumes that my math is correct.
 
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