Loss of power lower gears


Information and questions on GL1100 Goldwings (1980-1983)
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Prlwng
Posts: 62
Joined: Mon Aug 09, 2021 5:55 pm
Location: Brandon, sd
Motorcycle: 83 gl1100a

Loss of power lower gears

Post by Prlwng »



83 aspencade

2nd and 3rd gears, will lose power on hard acceleration. Upper rpms like 3500 up. Shift to 4th and into 5th power is as expected. Seems like it kinda missing in lower gears under hard power application.

Tryed to find anything on vacum advance stuff, but no luck. Went thru Clymer book also.

Think it could be related to preignition on takeoff sometimes. Rattle and ping.

Vacum line on #3 carb hooked up ok. Balanced carbs with New air filter.

Did have to balence 1 to 4/2 then 3/4 as could not set 1to 3, 2 to 4, then 4 to 3 without 1 going crazy.

Any ideas what next?


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OldguyGlen
Posts: 272
Joined: Sat Nov 24, 2018 10:55 am
Location: Mound,MN
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1980 GL1100 STD/Vetters
1966 Honda 90

Re: Loss of power lower gears

Post by OldguyGlen »

Might just be your perception of more/less power in the various gears. The engine doesn't know what gear you are in. It's world involves engine speed vs throttle setting and mechanical load sensed at its crankshaft. Under hard acceleration the load is primarily inertial acceleration of the bike's mass, plus some mechanical friction and wind resistance. The load would be heavier in the higher gears as that implies faster bike speed and greater wind résistance. Doesn't seem right that you perceive better power at the higher speeds, where the load is also greater. Try to concentrate on relative power at the SAME ENGINE SPEED in each gear. Above 3500 rpm there should be no rattle and ping. If there is, check basic timing. You can check vacuum advance with a timing light, but a quick check is to suck on the tube (carb #3)and listen/feel the response in the advance device (engine off), or idle response.
I balance the carbs 1 to 3, 2 to 4, then 4/2 to 3. I don't see how you can balance 1 to 4, then 3 to 4 without messing up the 1 to 4 settings?? But then carb balance mostly affects idle conditions. Above 3500 rpm carb balance is insignificant. (assuming it was even somewhat close at idle)
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biguns
Posts: 70
Joined: Tue Jun 14, 2022 3:39 pm
Location: Ardmore Oklahoma
Motorcycle: 1980 Interstate

Re: Loss of power lower gears

Post by biguns »

Something I had to work hard at unclogging was my accelerator pump jets, tiny little things in the center of each carb throat, even my smallest wire was to fat to go in, I forget what I used to get the unclogged but probably a bristle from something
Even when I thought they were unclogged some just squirted or dribbled but they actually spray when working right, your jets are setup to accommodate the extra fuel from these so it would make sense off idle/call for fuel performance would be affected.
How much I don't know but you could easily check them maybe with a camera looking into each carb throat from the intake or removing the intake manifolds at the head or lifting them up and sliding a piece of paper in-between, it should wet the paper with fuel after a few twist of the throttle and should be even in all 4 carbs. best way is to see them in action
This is all done with the engine off of course they have a mechanical accelerator pump
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