Knocking under load


Information and questions on GL1100 Goldwings (1980-1983)
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Chitownjohnny
Posts: 31
Joined: Sun May 19, 2019 1:01 pm
Location: Montello, WI
Motorcycle: 1981 GL1100

Knocking under load

Post by Chitownjohnny »



81 Gl 1100 has what sounds like a rod knock under load. 1st and 2nd no noise but once in 3 and I hit 4500 rpm it starts making a low knocking noise. It was running fine now this. Carbs were rebuilt in August and bike was winterized and was running well. I have been told the carbs can be out of sync is there anything else that it may be.


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DenverWinger
Posts: 2280
Joined: Thu Jun 23, 2011 2:20 pm
Location: Denver, CO
Motorcycle: (s)
'80 GL1100 STD Vetter (2005-)
'93 GL1500 Aspencade (2017-)
'83 Trav-Lite Camper (2010-)
Past rides
'72 CL350 (1980-1988) sold
'78 Suzuki GS550 (1985-2005) sold
'77 GL1000 (2002-2006) sold

Re: Knocking under load

Post by DenverWinger »

Doubtful it is Carburetor sync, that mainly affects the cylinder balance at idle and very light throttle. Once the throttles are opened to any degree the sync adjustment is insignificant.
There are 10 types of people in the world, those that understand binary numbers, and those that don't. :lol:

♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:
~Mark
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Lucky07
Posts: 53
Joined: Sun Mar 03, 2019 11:21 am
Location: Ottawa, ON Canada
Motorcycle: 1983 GL1100A Aspencade
1984 CB550SC (Sold it :( )

Re: Knocking under load

Post by Lucky07 »

Pull the plugs and see what they look like. If it's a combustion issue you should see it there, might have a cylinder running lean/heavy or with weak spark. If all plugs are the exact same I'd be leaning towards something mechanical (not so good) but easiest first would be checking the plugs.
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