Noise on shut down only

[BowlingSS]

I traded for my 80 XS11 SG. The bike was hardly running and leaking gas everywhere. It died on a long trip and the owner U-Hauled it to my house.

I just rebuilt the top end, cleaned the carbs and just started her up the other day. I noticed this before I bought the bike that when you turn it off it has a noise coming from the engine like a chain rattling. It is not coming from the top end. The engine is very quiet when it is running. I have not taken it for a test drive yet. I still have to set the carbs and replace the fuel lines and check it out.

Is it possible to post a video of the noise?

Thanks.
Bill

[jetmechmarty]

Post it on Youtube and post the link here.

[3Phase]

Hey, Bill, how many miles are on the engine? That could be the primary chain slapping the case, a little noisy but more or less normal depending on how much noise it's making.

You can post video and pictures by uploading to another site, then posting the link(s) in the body of your message.


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[GNEPIG]

I would sinc the carbs first as this could cause an imbalanced sound.
Other wise preform a chain tension adjustment and see if that helps.

Still hard to diagnose words...

[BowlingSS]

http://www.bjittech.com/IMG_0776.mov

Hope this works..

Bill

[BowlingSS]

I might need a better movie. The bike has 54K. Just did a topend job. Chain was adjusted.

Bill

[3Phase]

I might need a better movie. The bike has 54K. Just did a topend job. Chain was adjusted.

Bill

Bill, the movie is fine, the engine sounds great!

That sounds like the Primary chain and it's not adjustable but GNEPIG is right: you need to check the valve shim clearance, then synchronize the carburetors and set the idle speed.

Other than that it sounds most excellent!

.

[motoman]

I might need a better movie. The bike has 54K. Just did a topend job. Chain was adjusted.

Bill

FWIW......if you still tryin' to use the stock cam chain adjuster......trash it for an auto one. If the stock one is still in use, the shaft slipped back under decel, and it will never hold anyways, thats a given.
So, what say you as to the type of adjuster is in front of motor?
The previous all good advice!......but may be a bit 'overthunked' at this point.

[BowlingSS]

FWIW......if you still tryin' to use the stock cam chain adjuster......trash it for an auto one. If the stock one is still in use, the shaft slipped back under decel, and it will never hold anyways, thats a given.
So, what say you as to the type of adjuster is in front of motor?
The previous all good advice!......but may be a bit 'overthunked' at this point.

I have a auto adjuster ordered. Still has the stock one. All the valves are set. I had to change almost all of them. They were all tight. I did bench synch the carbs after cleaning. They looked very close. I think the previous owner had a shop do them. I have a mercury stick waiting for the synch.

I was also thinking the primary chain. Can that chain ever brake or mess up the cases?
The engine did have the trans mod but am not sure how long ago. The other owner was not very mechanical.

Thanks everyone.
Bill

[BowlingSS]

Bill, the movie is fine, the engine sounds great!

That sounds like the Primary chain and it's not adjustable but GNEPIG is right: you need to check the valve shim clearance, then synchronize the carburetors and set the idle speed.

Other than that it sounds most excellent!

.

I should of let the engine get hot before I started the movie. I did have to increase the idle so the carbs I am sure are off some.

Bill

[motoman]

I should of let the engine get hot before I started the movie. I did have to increase the idle so the carbs I am sure are off some.

Bill

Loose cam chain has the same effect, cams slightly out of time causes idle to drop and a bit 'lopey' idleing......BTDT, 33yrs. ago......but you HAVE ordered the RIGHT stuff. Change that adjuster, and do an ACTUAL carb-sync, idle mixture setting, and you'll be golden.

[trbig]

??? The end sounded like gears to me.. like when you shift from neutral to first some times and it grinds just a little bit before engaging.

Makes me wonder if it has the 1st gear problem and it's so stripped that when shutting down, the clutch discs slow enough to where they finally grab at the end and the gear can't hold any pressure?

Just guesses here. To debunk my theory, put it in gear.. like 2nd or 3rd, then hold in the clutch when you kill it and see if it still does it?

[trbig]

As far as the main hyvo chain, Yamaha says it's a "No wear" item but I've been into some motors where it's very loose and stretched. If what you're hearing sounds like a chain to you, then yes, it may be stretched. These motors turn backwards, so it will pull tension from the bottom side of that chain while running. When you kill it, slack will go back to the bottom side and possibly drag along the case until everything stops spinning, but I've never seen/heard of this happening? You can buy new ones, but they aren't cheap. Seems like last one I looked at was in the $130 range?

*Edit. Just went to partsnmore.com and they're $175 there.

[3Phase]

I should of let the engine get hot before I started the movie. I did have to increase the idle so the carbs I am sure are off some.

Bill

Like GNEPIG said, synch the carbs.

The Primary chain can slap a hole in the case but it's pretty rare. It can break too but that's even more rare than a broken case. The chain is pretty tough:-


Primary Shaft, Primary Chain and Clutch Damper Assy



Anyway, it sounds worse than it is because when the engine isn't pulling smoothly it plays jump rope with the Primary chain and damper while bouncing every bit of lash in all the gears and bearings on the shaft, the Oil Pump, the Clutch Basket and the Transmission.

Tod's got a good idea too. Put it in gear and hold the clutch while you kill it. That'll get rid of most of the Transmission gear and bearing noise.

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[jetmechmarty]

As far as the main hyvo chain, Yamaha says it's a "No wear" item

I believe it is the same chain that made the front wheel drive Toronado possible for 1966. The no-stretch chain was developed by Borg-Warner, IIRC. That chain handled 2 tons of car and over 300 hp.