Author Topic: What causes knocking?  (Read 1233 times)

DaWiseWun

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What causes knocking?
« on: May 07, 2005, 03:52:05 PM »
Just got done with the starter fix for a rattle, now it is knocking.  I can hear it the loudest when I let off the throttle at like 20 MPH and as the RPMs drop I hear this knocking sound.  Prolly not good.  Any ideas?

Josh
"Of course there's a lot of knowledge in universities; the freshmen bring a little in; the seniors don't take much away, so knowledge sort of accumulates.

QBS

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Re: What causes knocking?
« Reply #1 on: May 07, 2005, 03:55:37 PM »
When you say that you did the "starter fix" exactly what are you refering to?

DaWiseWun

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Re: What causes knocking?
« Reply #2 on: May 07, 2005, 04:33:09 PM »
I was talking about the starter clutch bolts that have loosened and getting new ones and peening ofer the threads so it doesn't happen again.

I prolly need to over haul this engine.  Is the haynes manuall pretty good at describeing stuff?  Since I basically rescued this bike from the junk yard it had been sitting awhile.  Any tips and tricks?  Also, is the haynes manuall in digital form somwhere?

Thanks,
Josh
"Of course there's a lot of knowledge in universities; the freshmen bring a little in; the seniors don't take much away, so knowledge sort of accumulates.

Lucky

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Re: What causes knocking?
« Reply #3 on: May 07, 2005, 04:48:31 PM »
Josh, I have the haynes & yamaha manuals, plus the yamaha parts fiche & wiring diagram on Cd. shoot me an email

When you did the starter clutch bolts did you also tighten the balancer shaft nuts too (both drive & driven) they should be tightened, locktighted red, & the locktabs (all you can) peened over.
--Lucky
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DaWiseWun

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Re: What causes knocking?
« Reply #4 on: May 08, 2005, 07:36:25 PM »
Nope, guess I'll tear back into it.  I'll shoot ya an email.

Josh
"Of course there's a lot of knowledge in universities; the freshmen bring a little in; the seniors don't take much away, so knowledge sort of accumulates.

QBS

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Re: What causes knocking?
« Reply #5 on: May 09, 2005, 02:59:21 PM »
Everything said above is on the money.  However, even with new tapered bearings properly installed there is a very strong chance that your front end will still have a knock in it when you rock the bike forward against the front brake.  The cause of this knock is located in the forks, not the stearing head.  I'm pretty sure that most Vs' have this characteristic.  My '83 was like this with its' factory stearing head bearing and... after wearing out the replacement tapered bearings and then replacing them, its' still the same.

This subject has been discussed here before, but not in a long time and not very definativley.  For me, the problem is only a minor anoyance and not worth fixing.  Cheers.

QBS

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Re: What causes knocking?
« Reply #6 on: May 09, 2005, 03:02:53 PM »
I messed and resonded to the wrong post.  MY above reply applies to the Loose Front End post.

Rick G

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Re: What causes knocking?
« Reply #7 on: May 11, 2005, 09:28:57 PM »
Thats OK Bob , we all make mistakes !lol ;D
Josh, before you think about  overhauling it check availability of everything  your going to need  at you local Yamaha dealer . pistons and rings are no longer avalable  in any size . I "rebuilt " my top end useing  some really decient low milage used stuff I collected . Soon we will see how it works.
Rick G
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'90 Suzuki VX800, 1990 Suzuki DR350.
'74  XL350   Honda , 77 XL350 Honda, 78 XL350 Honda, '82 XT 200 Yamaha, '67 Yamaha YG1TK, 80cc trail bike