[gl19751000]

Hey everyone,

Restoring a 75 GL1000 - the bike was starting but wasn't idling well. Pulled the carbs off and gave them a cleaning, then put them back on. Immediately once trying to start the bike, this 'knocking' sound started. No adjustments were made besides those to the carb.

Does anyone have any idea what could be causing it?

P.S. I know the spark plug wires are off - the noise was happening with and without.

Video with audio can be found here.

Thanks, everyone!

 

[rayworx]

Well... since the noise wasn't there till you pulled the carbs I would remove the carbs and crank the engine again. That's a nasty sound.

 

[tamathumper]

Can't watch the video, but could something fall down inside the engine when you had the carbs off?

 

[redwing52]

I agree with Tam. There well might be something that fell inside the engine. I would isolate which dide the noise is coming from. If you have access to a borescopw you could look in the cylinders. Otherwise isolate which side the noise is coming from. It certainly sound like a noise associated with a reciprocating part. Start taking the suspect head off and inspect as you move along just in case but it sounds like it might be in the combustion chamber or inlet port. The clink sound I hear makes me think something is in the intake runner and bouncing off the intake valve when it opens and closes. It might be laying on top of the intake valve and too large to go past. Can you fish a magnet sown the intake runner? Or turn the bike upside down. Seriously, Good luck.

 

[Pure Texas]

If you don’t sync the carbs there will be a knocking,it’s the primary chain causing It,some need replacing but sync the carbs and it will be better,
maybe not,I was thinking the engine was running

 

[DBohrer]

Could it possibly be a piece of "Carbon" laying on top of a piston....???

I could tell a story (true) about such a happening....!!!!! I resolved the issue (without turning a wrench).....!!

But the "Experts" can solve this one........!!

 

[Pure Texas]

I think it’s just the compression making the primary chain to slap,chain could be worn out

 

[DBohrer]

Its been soooo long since I had a GL1000 I have forgot most about them........

 

[Pure Texas]

Pull the plugs and cranke it over,I bet the noise goes away,

 

[DenverWinger]

I agree with Redwing52 in post#4, Sounds like something fell in the intake and is too big to get past the valve.

 

[Pure Texas]

Huum,another owner that doesn’t acknowledge there’s help here?

 

[redwing52]

I prefer to think he hasn't answered because he is riding. 😎

 

[DBohrer]

Some folks are just ungrateful................!!!

 

[david_root2000]

Yes, we are curious what it was.

This is the most polite and respectful forum i have been on.
I was a moderator on a welding forum for a few years. What a bunch!
One post wonder
David

 

[AZgl1800]

sometimes, Life just gets in the way and folks don't get back to us real quick.

 

[DaveO430]

I think sometimes it is embarrassment, not wanting to admit an oops.

 

[redwing52]

I think sometimes it is embarrassment, not wanting to admit an oops.

I laugh at my mistakes. I laugh a lot!

 

[GLblinded]

Hey everyone,

Restoring a 75 GL1000 - the bike was starting but wasn't idling well. Pulled the carbs off and gave them a cleaning, then put them back on. Immediately once trying to start the bike, this 'knocking' sound started. No adjustments were made besides those to the carb.

Does anyone have any idea what could be causing it?

P.S. I know the spark plug wires are off - the noise was happening with and without.

Video with audio can be found here.

Thanks, everyone!

Maybe replying to him will send him an email that says someone answered him. So I listened to the video, and agree with others that think something fell into the intake while the carbs where off. If a bore scope was available you could look inside the combustion chamber. Short of that, pull the head to look inside.

 

[AZgl1800]

if he gave a valid email address, he should be receiving emails about each post.
OR, if someone wants to send him a PM / conversation, that will definitely send him an email.
this is his Profile setup.

 

[tamathumper]

He's probably in the garage with his finger stuck in the intake plenum, from trying to fish out that loose nut.