'82 GL1100 Aspencade engine temp, knock, idle questions

[Chiller449]

Hello all,
I recently picked up a 1982 Honda Goldwing Aspencade GL1100. All the fairings have been removed so I guess you could call it a naked bike. Anyways, I cleaned the carbs on it and adjusted the valves. The bike runs decent but I have a loud knock SOMETIMES at idle. It will idle ok and then the rpm will very slowly start to drop and the motor knocks very loudly. Almost sounds like rod bearings. The noise goes away when I give it throttle. It could be rod bearings, I'm not sure there seems to be no bearing material or metal shavings in my oil when I change it. Another issue I'm having is after the engine gets warm it sometimes likes to idle at 3000 rpm. I have to let the clutch out in first and manual lower the rpms to get them to stay at around 950. If I rev it at all most of the time it will stay at 3000 other times it will idle normally. My last issue is coolant temperature. My bike will almost always stay running cold. After I ride it for about 25 minutes the coolant temp will slowly start to climb and stay about 1/8 inch above cold. It will almost never reach normal operating temperatures (center of gauge). Only if ive been riding for 30+ minitues and am sitting in traffic will it get to the center of the gauge. Only then will my radiator fan click on. Once I get gong its right back down to cool. Im guessing my thermostat is stuck open? Any ideas? Thanks!

[Maz]

These engines do knock loudly and/or rattle when the carbs are not set up properly, have a clogged idle circuit or are not TOTALLY clean inside. I would suggest a strip and thorough clean/rebuild of the carbs, followed by proper synchronisation when they are back on the bike.
The temperature problem could be a stuck thermostat or could even be a faulty gauge. Does the fuel gauge work properly? If not, you likely have a faulty 7v regulator.
Out of interest, when were the cam belts replaced? This won't affect your problems but will give you one very large problem if one breaks.
Maz

[Chiller449]

Fuel gauge works perfectly. Must be a bad thermostat. I Had somebody else tell me that the engine knocks loudly if the carbs are not synced right. Do they only do this at idle? I have no idea when the timing belts were changed. The bike has 36,xxx miles. How often should they be changed?

[Maz]

The engine knocks at idle if the carbs are not right because of the uneven firing pulses across all 4 cylinders. The noise is mainly caused by the slack in the primary chain (no chain tensioner on 1000's and 1100's). Above idle, the higher speed of the engine keeps the chain taut.
If you don't know when/if the belts were changed, do it now, before running the engine again. Check out the "how to's" on here for full details. It's not a huge or expensive job.
Maz

[Chiller449]

Sounds good, thanks for the input.