Can't figure out where this came from?


17 replies to this topic
  • WNY_06S3

Posted July 14, 2009 - 12:10 PM

#1

Checking valve clearances today and when I took the cylinder head cover off this fell onto the garage floor.... I've had the head cover off a time before but don't remember ever seeing this piece. Its semi hard plastic with two circular indents on one side.

Valve clearances seemed to be on the lower side of within spec so I'm going to leave them for now since the weather is nice. Any help with identifying where this piece goes would be greatly appreciated. This is my first time posting a picture so hopefully it works. If better pictures are required to identify it please let me know.



http://s658.photobuc...nt=DSCF0231.jpg

  • KJ790

Posted July 14, 2009 - 12:49 PM

#2

I believe that is the cam chain guide that is supposed to be glued to the underside of the valve cover (above where the cam chain runs).

  • grayracer513

Posted July 14, 2009 - 01:04 PM

#3

I believe that is the cam chain guide that is supposed to be glued to the underside of the valve cover (above where the cam chain runs).

I believe you're right.

  • BigB250F

Posted July 14, 2009 - 07:35 PM

#4

Yep, that 's what it is. I had one come loose on my 250F and freeze the motor up. The mechanic at the shop told me you could stick it back in place with JB weld if it is not damaged...I do not know what kind of glue you could use.

  • grayracer513

Posted July 15, 2009 - 05:57 AM

#5

The mechanic at the shop told me you could stick it back in place with JB weld if it is not damaged...I do not know what kind of glue you could use.

It came off once, there's no reason to think it will stay on. If there's no significant damage to the mounting pegs in the cover, get a new one. You can use 3M Super Weatherstrip Adhesive or epoxy to help it stay put.

You should also examine your cam chain carefully for kinking. Under most normal circumstances, nothing would hit that hard enough to dislodge it.

  • matt4x4

Posted July 15, 2009 - 07:19 AM

#6

degrease everything scuff it with a dremel and jb weld it back on

  • WNY_06S3

Posted July 15, 2009 - 08:59 AM

#7

Thanks for the help everyone......There is no damage to it. It must have hit something while I was trying to shimmy the cover off. Still decideing whether to jb weld it or use epoxy. I'd imagine jb weld would work better?

  • grayracer513

Posted July 15, 2009 - 09:33 AM

#8

Thanks for the help everyone......There is no damage to it. It must have hit something while I was trying to shimmy the cover off. Still decideing whether to jb weld it or use epoxy. I'd imagine jb weld would work better?

Spot quiz: What's the difference between JB-Weld and epoxy?

(hint: same as Toyota/automobile)

Personally, I'm not that convinced JB would bond well to the rubber, especially since it's been exposed to hot oil for so long. I think I'd trust the 3M SWA more. Either way, the bond will be better with a fresh piece.

I also seriously doubt you dislodged it accidentally while removing the cover, unless, as I suggested, there was something wrong with how well it fits.

  • matt4x4

Posted July 15, 2009 - 10:46 AM

#9

I don't think that plastic piece is rubber - it is made from the same material as the chain guides - injection molded plastic.
Now maybe they changed it over the years but on my bike it's plastic and looks identical.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • WNY_06S3

Posted July 15, 2009 - 10:54 AM

#10

gray -For some reason I always had it in my head "epoxy" was used for only plastics and similar materials. I understand now jb weld is an epoxy, thanks for clearing that up before I sounded dumb, oh wait..........

Matt, after looking at the piece again I believe you're right about it being injection molded plastic.

thanks

  • grayracer513

Posted July 15, 2009 - 11:09 AM

#11

I don't think that plastic piece is rubber - it is made from the same material as the chain guides - injection molded plastic.

Spot quiz #2: What's the difference between "rubber" (as commonly used to describe products such as neoprene, Viton, Buna, etc., not the product of rubber tree sap) and plastic?

(hint: same as above)

"Rubber" has long since become a generic term describing a variety of rubber-like products, 99% of which are synthesized from various materials, and are in fact plastics (which always was an extremely nondescript, generic term). This includes the tip of your float needle, the O-rings in you chain and elsewhere, and your tires. The rubber/plastics argument regarding the chain guides is one of semantics only, and my concern over epoxy being able to bond to them successfully is the same whichever term you prefer to use.

  • yoshgixxer

Posted July 15, 2009 - 03:40 PM

#12

byson combi metal is a metal based epoxy that stands up to oil and hi heat much better then JB...JB weld will break down from oil and gas..some guys use byson combi for flow bending and it holds up for them....

the best stuff would be 3M panel bonding adhesive..its a touch expensive unless you live by a body shop they would probably glue it for free...that is some serious epoxy..stronger then a weld...but HAS to be oil free and scuffed up with 220 grit atleast..you can rig LOTS of stuff with that:lol:

  • matt4x4

Posted July 16, 2009 - 03:35 AM

#13

Grey - where I live, rubber is something naturally derived that comes from certain trees in a sap form, but plastic is a petroleum product which is manufactured. Maybe around your parts, they squeeze petroleum from trees and drill for rubber, but around here, that's not the case, there is a world of difference between the two products. Look it up.

The "rubber" you decided to define is stolen by the petroleum industry to describe plastics that have rubber like properties, however are NOT nor will they ever be "rubber", they will only be "rubber like".

BIG difference.

And that part is not "Rubber like" since it does not have "rubber like" qualities, it is plastic.

  • grayracer513

Posted July 16, 2009 - 05:50 AM

#14

So you don't refer to the material used in tires and O-rings as rubber, Matthew? Right.

  • matt4x4

Posted July 16, 2009 - 09:18 AM

#15

to be 100% accurate, no they should not be referred to as rubber, "synthetic rubber", yes, "rubber", no.

Either way - whether you want to call "synthetic rubber", "rubber" or "stretchy stuff" still has no bearing on the fact that this plastic piece the OP is talking about is hard, not stretchy and "rubber like". And it will glue in perfectly fine with JB weld as long as both surfaces are clean and free of oil and have been roughed up a little.
JB weld Glues virtually anything and is chemical/oil resistant.

  • grayracer513

Posted July 16, 2009 - 10:56 AM

#16

The point is that you and everyone else calls a wide variety of plastics "rubber" and you do it every day, so it matters not what is technically correct. Your original purpose in raising that issue was to be argumentative.

JB Weld is oil resistant, yes, once cured. But the problem is that rubber/plastics with higher levels of elasticity tend to absorb oil and petroleum solvents when exposed to them for long periods. Quite often, simply degreasing the visible exterior is simply not enough to guaranty a good bond, which is one reason I recommended a new guide. Enough absorbed solvents can migrate to the surface during the long cure time JB requires to have a detrimental effect.

The second reason why I would use 3M SWA, or one of several different gasket sealers, instead, is that they can be removed far more readily that a two part epoxy, should the situation call for it. It would be different if the adhesive were expected to hold the part entirely on it's own, but in this case, all we're looking for is a supplement to the fastening system intended for the purpose.

  • SC_Spode

Posted July 16, 2009 - 02:42 PM

#17

Since we're being exact here, I guess we shouldn't use the following term in a sentence -

"Honey, did you bring your rubbers?"

Instead, we should probably say -

"Honey, did you bring your galoshes?"


:worthy:

  • grayracer513

Posted July 16, 2009 - 02:54 PM

#18

That depends. But, End of Discussion, nevertheless. :worthy:





Related Content

Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies
Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Forums
Photo

The "going back to the other darkside" adventure... by Monk


Dirt Bike   Make / Model Specific   KTM   250/350/450/505 SX-F & XC-F (4-Strokes)
  • Hot  94 replies
Forums
Photo

Snake pit oct 30th by The Anvil


Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.