first valve check on a 450

[coolbikeguy]

hey guys this is my first shot at doing a valve check on a 450. can some one please tell me the secret to getting the feeler gauge to slide in to check the intake valves ?? im having a heck of a time getting it to slide through. also, my exhaust valves were left .010 and the right .011 i am a little confused though about the decompressor check.. correct me if im wrong but i take the .011 and add.014 for a total of .025 correct ? so the gap under the adjustment screw should be measured with a .025 gauge correct ? why do you need to add this difference ? ( please excuse my ignorance on this ). i also thought i read something a while back about changing the .014 so that the decompressor opens a little further allowing the bike to start a little easier. anyone know what it can be changed to ? maybe .011 + ?? sorry for the lengthy post but my valve cover is off and i have limited time to finish this service before ( hopefully ) riding on sunday. thanks in advance guys, scott

[moabrules1]

The intake clearance should be .006"+/-.001". If none of these fit, keep reducing the feeler size by .001". If you get down to .001", and you still can't get the gage in, your valves just went to zero and it's time to consider replacement.

[sonobob]

Are you using the angled tappet guage style?

(just curious...those are a bit easier to deal with)

[EddieTNT]

Are you using the angled tappet guage style?

(just curious...those are a bit easier to deal with)

You can bend the end of the straight gauges easily. It helps alot.

[sonobob]

You can bend the end of the straight gauges easily. It helps alot.

I just never tried that, knowing how my luck runs with those kind of things...

I'd end up with a bunch of worthless broken feeler guages!

I went the easy route and sprung the $4 for the set that someone else had already bent!

[coolbikeguy]

i tried straight and bent and neither wanted to fit. it was getting late so i covered the top end and i will give it another shot tonight before leaving for maine. assuming the intakes valves are shot .. are the intakes normally the first ones to go ? just curious because my ex valves are right in spec. also if the intakes are shot will this have anything to do with a hard starting problem ? and finally i know its silly but is it stupid to just get the intakes done since the exhaust valves are still in spec ?? thanks again guys, scott

[sonobob]

To throw out another probable silly question...you are certain that you're marks are aligned on the compression stroke, right?

[coolbikeguy]

To throw out another probable silly question...you are certain that you're marks are aligned on the compression stroke, right?

yes .. thats actually another issue. the book says when you are on the compression stroke and marks lined up that your can move the exhaust rocker arm ... how much should it move ?? mine moves a minimal amount but when i rotate it around one more time it will NOT move at all. so im assuming when it moves that minimal amount im right where i need to be ??

[Racer24]

well when u figure out how to do it...this is the equation to go by when u are trying to figure out wat shims u need

Now to figure out wat shim u need use this formula A=(B-C)+D

A) The shim needed to get the right adjustment

Measured Valve Clearance (make a chart for LEFT, RIGHT, EXT, INT)

C) The clearance u are trying to obtain (wat ever it is in the manual)

D) Present shim thickness (wat was under the buckets or rocker arms)

hmmm wat else...also im not sure because iv'e been with kawi my whole life, but is the decompressor on the exhaust cam, an auto-decompressor....also the feeler gauges should be able to slip in between the lobes or rocker arms, with the smallest amount of force, should not have to really give it a shove to get it in there..

since i just got my 07 kxf and i havent gone through a reshim job yet, i remeber on my yamaha 250f, when ever i had to reshim i always made sure the clearnences were the tightest they could be...so if they say the exhuast is .17-.22, i would go around .17 or .18, that way u get the best out of ur motor....

and im running out of ideas....

[freeride7]

You intakes need replacement. They do go well before the exhaust do. I did 3 valve jobs on my old 04 Crf 450..and just did one on a 05 crf 250x. No issues on my 06 so far...

The feeler should slip in with some slight resistance...if it isn't, the valves are zeroed....replace them. A reshim will only get you a few more rides ( Believe me, I tried the quick fix and my 7 day ride in Baja Mexico ended on day 6!! )