first gear noise

[barsnake]

I have a 1978 GS1000 with a loud noise in the front sprocket area during hard acceleration. It feels like it's not catching somehow. It only happens in first gear and only when I launch fast, other then that it runs fine. The clutch doesn't slip in any gears and it shifts smooth. The first time it happened I was on a hill with my wife on the back. I started to roll back a little and needed to rev the engine slightly while working the clutch to take off. That when I felt it first. If I drive it normal it's fine. Once I'm rolling in first I can gun it and it doesn't happen. I checked the front sprocket spine and its Ok. The chain and both sprockets are new. Any ideas?

Thanks Pete

[BassCliff]

Greetings and Salutations!!

Hi Mr. barsnake,

How long has it been since you replaced the chain and both sprockets? They should be replaced as a set, you know. Let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

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BassCliff

[barsnake]

Chain and sprockets

I replaced the chain and both sprockets early last year. The clutch is from Barnett and it's 3 years old.

Thanks Pete

[reddirtrider]

Your output shaft bearing could be on the way out. Give it a wiggle and see if there's any play at all. If there is you'll need to replace it before it gives out and creates a big mess.

[barsnake]

First gear noise

Checked for play and couldn't find any. Do you think it could be the clutch? I've never used motorcycle oil with the bike, just regular 10.40. which isn't recommended but after 30 years without any trouble I figured it's probably OK. I'l probably find out sooner or later what the problem is.

Pete

[Don-lo]

Very strange. What did you "feel" and what did you "hear"? (2 different things). I think you are not getting much feedback because the usual suspects (chain and output bearing) have been suggested.

Maybe a loose motor mount?

[Zooks]

Don't launch hard and change into 2nd as fast as possible. Problem solved.

Seriously though, it sounds like a missing tooth to me. Check every tooth (both cogs) and every single chain link.

[reddirtrider]

You replaced your chain and sprockets, but have you cleaned and lubed them recently?

[Steve]

You replaced your chain and sprockets "early last year", but how many miles on them?

Some people only ride a couple thousand miles a year, so the chain and sprockets would still be virtually new.
Others, like me, ride an average of 17,000+ miles a year. Might they be wearing out already?

.

[barsnake]

First gear noise

The chain and sprockets have very low mileage. Maybe 1500 total. I use chain wax spray regularly and never let the chain get loose. The sprockets are in excellent shape. The noise is hard to explain. It's like a screech sound and it feels like a gear spinning on a shaft because there is a momentary loss of power. I can't duplicate it in any other gear and it only happens when I'm letting the clutch out in first. Once it’s fully released and I'm moving I can open it up with tons of acceleration and there's no more noise. The noise comes from the front left sprocket area but I'm beginning to think it’s the clutch springs bouncing. I'm a new member to the GS recourses and have been enjoying all the responses.

Thanks Pete

[tkent02]

It's like a screech sound and it feels like a gear spinning on a shaft because there is a momentary loss of power. I can't duplicate it in any other gear and it only happens when I'm letting the clutch out in first. Once it’s fully released and I'm moving I can open it up with tons of acceleration and there's no more noise. The noise comes from the front left sprocket area but I'm beginning to think it’s the clutch springs bouncing.

Thanks Pete

That description sounds like a bearing failing, if it only happens when the clutch is engaging, look there first. there are two bearings which only spin while the clutch is released and the two parts are turning at different speeds. Does not sound like a transmission shaft bearing or engine bearing, or it would do it at other times???

[barsnake]

I'll check the clutch roller bearings.

Thanks