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Discussion Starter · #1 ·
Hey guys, first huge thanks to this forum. You guys are amazing and have helped me so much in this dream of rebuilding a bike.

So here's the problem I've run into: My GL650 has increased engine noise (I think it is transmission related) whenever I am riding in the 2500-3000rpm range. It's not there at any other range. I've only noticed this noise the last two times I rode it and am no longer riding until I figure it out.

Here's what I know:
1. The noise is only present when in gear and under load. I put the bike up on the center-stand, ran through the gears, no noise.
2. The bike has been running fine for the past month with no odd noises. The only thing I changed is reinstalling the H-Box. I shook it around before I installed it and could not hear anything rattling.
3. I haven't checked if I can fluctuate the noise by using the clutch, I'll check that tonight.
4. Here's a quick list of what I've already fixed on the bike: Rebuilt Carbs, Replaced Head Gaskets included cleaning and lapping the valves and checking and double checking the valve gap, replaced valve stem seals as well. Replaced cam chain, auto-tensioner and guide are in good condition. Standard maintenance: coolant flush and refill, oil change, new spark plugs, grease drive shaft and change oil in the rear.....??transfer case?? (I can't think of the right term right now, but you know what I mean)

The bike runs great otherwise, there seems to be a slight bit of oil burning in the right cylinder. Smooth throttle response throughout the whole rpm range and no backfire when engine braking.

This noise is driving me crazy, I love engines and want this bike to pur. It currently has 23,000 miles on it. I'll try to post a sample clip on youtube tonight and include that link here.

-Cheers
 

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You should not be riding in that low of rpm, it will starve the valves of oil.
Best results are had @ 4k and up.
These engines love to run up in the 5 to 8K range all day long with no problems.
 

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Discussion Starter · #3 ·
Ok, good to know. I've been riding at 3500+, but I'll switch to 4k+. I'm still worried because ideally, it should be smooth sound all the way through the acceleration.
 

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Yeah, the oil pump does not provide sufficient pressure at that low rpm to properly lube the cam and valves.
So lugging the engine like that is not recommended.
Have you done a valve adjustment?
Some of the sound you hear is more noticable due to the heads sticking out as they do.
If you do not have the FSM, you can download it at the link in my sig. Be sure that you also get the addendm for your year/model.
 

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The noise could be something loose such as a muffler clamp, fairing bolt or anything any where on the bike.
Go over every nut and bolt and check for tightness. At certain RPMs the engine has some vibrations that can make
a loose part rattle. Do all the simple stuff before you dig deep.
 
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