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Knocking, Tapping In Top Of Front Cylinder (SOLVED)

PostPosted: Sat Aug 28, 2010 12:06 am
Author: 1986 XV700
This post started out as a question until I decided to check my valve clearance "just one more time." I'll go ahead and tell you the problem wasn't valves, rocker arms or cam.

My bike decided to join the front cylinder knocking club yesterday morning on my way to work. For the past year or so its had a persistent light tapping sound that would occasionally get loud on deceleration but usually what might be better described as a tick. This evening I decided to figure out what the problem was since it was now embarrassingly loud and really had me concerned.

I checked all the normal things one would check:
Oil Level - Good.
Valve Clearance - It was out pretty bad but proved not to be the problem after I corrected it.
Rocker Arm Play - There was a little side to side movement on the shaft but there wasn't any movement to make me think the pivot hole was worn.
Oil Flow/Pressure - Cranked up the bike with the front intake valve cover off and oil splatter everywhere and puddled on the floor.

When I cranked the bike with the valve covers off I also had the cam cover off. I looked in at the rotating cam end and noticed the chain slapping the cylinder head in rhythm with the tapping sound. Now it was clear the chain tensioner must have a problem right? It did, would you like to see it? Before you look I'll tell you what I found and how I fixed it.

The problem was one end of the clock spring was no longer connected to the tensioner housing and therefore couldn't apply proper tension to the tension pin. From what I could tell the fixed end of the spring was supposed to be in a hole that is partially drilled in the side of the spring cavity. I heated the fixed end of the spring and formed a hook in it that would fit into the cavity. Because I wanted it to stay put I wedged it into the hole with the hollow aluminum portion of a 1/8" pop rivet. The rivet isn't "set" just gently tapped in to keep the spring in place.

Before winding the spring into place I twisted the tension adjustment pin to the left tightly to keep it in place and hold the tension pin fully extended. I was then able to twist the tensioner housing, winding the spring into the cavity. Once wound into the cavity I put three additional twists on the spring to supply tension to the pin while extended. The cap was bolted back into place and I retracted the tension pin by twisting the adjustment pin tightly to the right so it would stay put. After installing the tensioner back into the engine a slight left twist on the adjustment pin and I heard it zip back into place.

I restarted the bike with the cam cover still off and it actually sounded better than a sewing machine. A sewing machine ticks, my bike don't. Yeah baby, the sweet sound of success!

Here's a few pictures of the disassembled tensioner:
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PostPosted: Sat Aug 28, 2010 8:46 am
Author: Roger Ramjet
And you couldn't figure that out while my old bike was still breathing LOL ..

Joining the ticking front cylinder club is better than joining the I was riding along and it seized up club ... The entry fee's for that one are way higher .

Hopefully you got a permanent fix now .

R.Ramjet

PostPosted: Sat Aug 28, 2010 9:14 am
Author: ghostdad
Roger Ramjet";p="220688 wrote:And you couldn't figure that out while my old bike was still breathing LOL ..

Joining the ticking front cylinder club is better than joining the I was riding along and it seized up club ... The entry fee's for that one are way higher .

Hopefully you got a permanent fix now .

R.Ramjet



I totally agree RR, now that I'm a new member to the seized up club...LOL

PostPosted: Sat Aug 28, 2010 9:32 am
Author: Roger Ramjet
i got luckty with mine , in my search for a replacement engine I bought the one in my signature picture , and as it turned out it has lower milage , better tires and runs really good , all for $350 .


mine was the putting oil filter in backwards one

PostPosted: Sat Aug 28, 2010 10:01 am
Author: 1986 XV700
Sounds like shopping for printer ink. Sometimes its cheaper to buy another printer. Get newer technology and new ink.

Having an engine seize up has got to be the ultimate bummer. I'm glad you got a better replacement.

Here's my $0.02 on checking for oil flow in the engine. The suggestion to loosen the banjo bolt at the head is good it proves your engine has oil pressure to the head. If you remove the cam covers and crank the engine you should see a steady stream of oil pouring into the chain cavity below the cam gear. That proves pressure and volume, its not as messy and it looks pretty dang cool

PostPosted: Sat Aug 28, 2010 10:37 am
Author: Roger Ramjet
I used to do that , I guess I was in to much of a rush this time . Oh well sold off most of the old one now , and the rest is supposed to be picked up Sunday .

PostPosted: Sat Aug 28, 2010 2:07 pm
Author: Matthew
start your own clean, repair n rewind service ;)

Send your un sprung parts n pieces with $20 + $1.95 shipping to

P.O. Box
Winding Works
123 Main st
AnyTown, USA

Re: Knocking, Tapping In Top Of Front Cylinder (SOLVED)

PostPosted: Sat Aug 28, 2010 6:09 pm
Author: 1986 XV700
That's an idea that might work if this wasn't so easy a caveman could do it.

If there are any old dinosaurs out there though ... send it on in to XV700's Tensioner Repair Service. Our motto is, 'If we can't fix it we can fix it so it can't be fixed.'

PostPosted: Mon Aug 30, 2010 8:53 am
Author: soccerguy83
Ok gonna show my lack of engine knowledge. Could this also be a problem on the 535, my engine has a nock to the upper end of the front cylinder and it's not the valves. Not trying to thread jack, if the mods want me to move it I will.

Thanks

PostPosted: Mon Aug 30, 2010 9:45 am
Author: 1986 XV700
I'm not sure about the design of the tensioners on the 535's but I know they have them. Given that the cause of your noise could be a bad or malfunctoining tensioner.

PostPosted: Mon Aug 30, 2010 10:13 am
Author: soccerguy83
Sounds good, will have to do some research.

Re: Knocking, Tapping In Top Of Front Cylinder (SOLVED)

PostPosted: Fri Oct 22, 2010 11:49 pm
Author: classclown
I too have the occasional "tick" on the front cylinder. I haven't looked into it because it doesn't sound "life threatening", but I was steering toward an exhaust leak at the head pipe connection. It's not constant, but does come and go regularly. Maybe I too have the same issue wsith this tensioner you speak of?

1987 XV700

Re: Knocking, Tapping In Top Of Front Cylinder (SOLVED)

PostPosted: Thu May 12, 2011 7:28 am
Author: zfoxfire
I'm glad I read this.This problem has been developing lately in addition to a failing ignitor box so I didn't stop to think about my tensioner possibly going bad. I just took my garage queen out of storage and am working on her again. I'd rather not join the siezed-enging club so soon. I'll be checking my valve clearance and chain tension today. Thanks! :)

Re: Knocking, Tapping In Top Of Front Cylinder (SOLVED)

PostPosted: Thu Jan 01, 2015 6:23 pm
Author: YamahaFamily
Great info! Thanks!