Checking Valve Clearance - Shortcuts?

Started by Toby_S, Oct 23 2002 04:06 AM
16 replies to this topic

  • Toby_S

Posted 23 October 2002 - 04:06 AM

#1


I was scanning the manual, and they start with removing radiators and carburetor for checking clearance. Is this necessary, or can I leave one or the other on? I don't want to make it a pain, or risk getting dirt in the engine, but if it's reasonably do-able, I'll take short cuts.
I'm doing my first check, and I'm thinking there's a good chance I won't have to do any actual adjustment.
Also, is a special feeler gauge required? I have garden variety automotive, and I can get those small ones they sell at the aftermarket shops.
Thanks,
Toby

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  • Dodger

Posted 23 October 2002 - 05:31 AM

#2

No, you do not have to remove the rads or carb to check your valves. That being said, do make sure the rads are free of dirt, you will be working in the area, and don't want to risk bumping dirt off and having it end up in your head.

I actually wrapped everything in the area with a little plastic wrap to be sure.

I don't know all the types of feeler guages, but I used the basic one you get at an automotive store........

Peace

Dodger :D :)

  • ITFC

Posted 23 October 2002 - 05:55 AM

#3

I just checked mine for the first time. I removed the radiator, but not the carb. Looking at it now you do not need to remove the radiator either.

Just a quick question. What tpye of sealant are people using on the head?

  • mikeolichney

Posted 23 October 2002 - 06:32 AM

#4

The standard width automotive feeler gauges I had worked fine on the 400/426, but the middle intake on the 250F was too narrow to fit them. You could grind them, I suppose, but I bought a set of six narrow ones on stalks (2 per stalk) that worked really well from my Honda dealer. These are doglegged so the feeler gauge doesn't bend when you insert it. It is very easy to tell when you have clearance.

I use Hi Temp blue automotive RTV silicone sealant. I dont remove the carb or rads. I wrap the bike backbone in plastic bag before removing the head cover so no dirt falls in.

  • YZ250F_Rider

Posted 23 October 2002 - 06:36 AM

#5

Take the seat off.
Take the 2 bolts that hold the shrouds to the radiators out.
Take the 2 bolts that hold the tank to the frame out.

Lift the tank and shrouds off as an assembly.
Now before you do anything else wash the frame good and let it dry. You will be climbing all over it and you dont want dirt falling into the engine.


I have checked mine a "lot", and haven't used any sealant. No leaks in a year.
As for the feeler gauge, all of them trim easily with a pair of good scissors. I made mine 1/8 - 3/16" wide at the tip and tapered them to about mid length back. You need to do this to get them to fit.

  • Dodger

Posted 23 October 2002 - 08:10 AM

#6

Sealant :D, uh oooohhhh...........I didn't use any sealant, should I have??

Dodger :) :D

  • SUnruh

Posted 23 October 2002 - 08:25 AM

#7

dodger,
YES!
according to the manual.
they even show a diagram of exactly WHERE to put it and where it is NOT needed. basically along the half moons on the left half of the cover. none on the right side.
i re-used my old original one. i have a new one, but the original was fine.

  • Dodger

Posted 23 October 2002 - 08:56 AM

#8

Aside from the gasket, your supposed to use some kind of sealant around the half moons...........uuummmmm, what kind?

Dang, hope I'm not getting crap in there :).........

Dodger :D :D

  • SUnruh

Posted 23 October 2002 - 09:31 AM

#9

let me run out to the shop.
i looked in the manual while i was out there: it says Yamabond 1215.

i used Permatex 2B (black, non-harding gasket sealer).

i would HOPE you are not getting anything in it. hard to say.

  • YZ250F_Rider

Posted 23 October 2002 - 09:50 AM

#10

I would think oil would leak if there was a sealing failure since the top of the head is bathed in it.

  • Dodger

Posted 23 October 2002 - 10:23 AM

#11

Yeah, I'm not getting any kind of seepage or leakage at all..........BUT, will undo, and seal properly to be sure.

Thanks guys as usual.........(banging head against the wall).........

BTW, I guess that's my contribution to valve checking shortcuts........just not very recommended :D!!!

Peace

Dodger :) :D

  • SUnruh

Posted 23 October 2002 - 10:41 AM

#12

dodger,
actually i don't know if i would open it if i were you.
if it don't leak, leave it be!
i looked at that gasket real well (to see if i could reuse it) and it is very well designed. double ribbed in the inside and nice and soft. it doesn't have to hold any pressure and is not a critical fit (like the cylinder base) so i would think you are fine. if it drips, tear it down. until then -> just ride!

  • YZ250F_Rider

Posted 23 October 2002 - 11:21 AM

#13

Or in SUnruh's case:

if it drips, tear it down, well after the season that is. until then -> just ride! :) :D

  • SUnruh

Posted 23 October 2002 - 11:26 AM

#14

exactly!
i only have 3 more weeks till the season is over with. a race next weekend and then 2 weeks later.
plus i don't have any of the parts (rings or seals) on hand to fix it yet.
mine drips, his don't, so YEAH! the reverse applies. :)

  • Dodger

Posted 23 October 2002 - 12:08 PM

#15

Cool enough........I'll be checking the valves again in a few months, so until then, I'll just keep a eye on it......

Thanks for the advice.....

Peace

Dodger :) :D

  • ksp

Posted 24 October 2002 - 04:43 PM

#16

I put a little black silicone on the "half moons" it's easy and probably helps. If you don't do it I don't think it's the end of the world.

  • Wyatt

Posted 24 October 2002 - 05:24 PM

#17

I have had my valve cover off 3-4 times and I have never put sealer on the gasket. I am always careful with it and I have no leak whatsoever. I'm not saying my way is right, but it has worked for me.



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