Valve adjustments

[Knarf0486]

It's time for me to check and adjust my valves, but I have yet to get a manual because I'm spending all my money on other parts. I was wondering if someone could help me out and name the steps for me. I've adjsuted them numberous times on my 400 but have yet to do them on my 06 450r.

Thanks

[ryann mx68]

hey knarf, check out this site

www.rockinhorseweb.com

look under trx mods, cam install and follow directions. also do the clutch mod.. its nice

yeah, i did forget it...........fixed now

[Knarf0486]

I think you mighta forgot to post the site address

[Knarf0486]

so there is technically only one tappet (I think thats what its called) to actually adjust the valves from? I'm gonna check my clearances tonight and see how everything goes.

you adjust the valves by changing shims

[Knarf0486]

I'm kind of confused on this concept of the shims. Do I need to change them when I'm just doing routine maintainence? I haven't made any changes from stock on my bike, I just thought it was like on my 400 where you bring the motor to TDC and slide your feeler gauge in to check valve lash and if it was out of spec then you adjust it to what it is supposed to be.

[Johnny B]

it is the same thing by bringing the piston to TDC, but the difference is that you cannot ajust the valves on the 450s like you would on the 400 with a screwdriver and a wrench. if the valves are out of spec, you ned to take the cam holder off and replace the shim on top of the valve. thinner or thiker depending on what the clearence of the valve is. if you dont have extra shims you cannot ajust the valves.

[ryann mx68]

yeah, sorry about the confusion.

under the cam lobes [intake] shim-under-bucket style

the exhaust doesnt have a bucket, only the shim on top of the spring

if its [valve clearance] out of spec, youll need a shim kit or see what size shims are in there and measure to see what size you need. the shims are marked with sizes

having a shim kit really helps though. ive got the hc st2 cam and the shim kit, but you could get just the shim kit for $70 or so.

[Knarf0486]

O that sucks. So I need to check to see if there out of spec and then take care of it from there. Do I completely replace the one that is in there or what? How often do you need to replace em?

[cals400ex]

ok this is hard to explain to some, especially if you have not read the manual. lets take the exhaust valves first. you will see a rocker arm that activates the two exhaust valves. it is somewhat shaped similar to a tuning fork. this one rocker arm rests on top of shims that sit on both exhaust valves. if your clearance is too big, you need to put a larger shim on the the corresponding exhaust valve to decrease the clearance between the rocker arm and the shim. this works in reverse too. if you have too little clearance, you need to put in a smaller shim so this in return will give more clearance.

now, on to the intake valves.

on the intake side you have no rocker arm. the camshaft directly operates the two intake valves. the cam lobes will hit a bucket. this bucket sits right over the valve/valve spring. right underneath this bucket is one shim that rests on top of the valves. once again, you have one shim on top of each exhaust valve. to check the clearance you need to stick the feeler guage between the bucket of one of the exhaust valves and the cam shaft. if the clearance is too much, you need to put in a larger shim to decrease the clearance. if the clearance is too little, you need to put in a thinner shim to increase clearance. now, you need to do this for both exhaust valves as well. so you will need to go to the other exhaust valve and stick the feeler guage between the bucket and the camshaft lobe on this side as well.

OK, there is a BUNCH of different sized shims. it is very possible that you will need different numbered shims in all 4 locations. you may need a 210 at one place, a 220 in another, a 280 in another, and a 310 in another, etc. of course these won't be the right numbers for your bike but i am just saying do not get worried when you have different sized shims on top of the valves. it is possible that you may use the same sized shim a few times. it totally depends on your top-end of your bike. they all vary!

[cals400ex]

if you are lost with what i am saying you need a manual bad! i am explaining it in simplier terms than the manual does. you just need to read and comprehend what it says or take it to someone with some experience. that rockinwebhorse article is very very very very helpful as well. you should be able to get the job done without the manual if you have that print out.


now, after you check the clearance it is time to change shims right?? ok, how do we know how much bigger or smaller we need to go on the shims?? first off, you need a shim kit. this isn't exact science and it will be hard to get all 4 valves at exact spec. that is ok, a hair off will not hurt anything at all. once you get the shim kit you will see a ton of different shims with different numbers on them. these shims are measured in millimeters. so, a shim numbered 220 is 2.20 millimeters. one measuring 300 is 3.00 millimeters, etc. and so on. you need to have a piece of paper with you and a pen along with a calculator. start with one valve. it doesn't matter where. stick the feeler guage in and see what clearance you have on that particular valve. don't worry about where it should be just yet. just see what clearance you have right now! remember, do not start unbolting the cam or cam tower yet. you need to check these clearances with everything in place besides the head cover of course. so, now you should have your valve clearance for that one valve you started with. now you need to follow that formula in the manual or on the rockinhorseweb site. i am not sure if there is an easier way to explain it than that. this is somewhat guess and check. you may put new shims in and they could still be off. so you would have to take the timing chain and cam tower back off and change shims again. then you need to adjust the shims and TORQUE the cam tower back on and put the cam chain back on. and make sure you are still at top dead center. heck i may have forgot to tell you that in the first place. before you can check for the proper clearance you need to make sure you are on top dead center on the compression stroke. if you do not have any clearance at all, you are not on the compression stroke and you just need to rotate the crank one revolution back to the Top Dead center mark on the flywheel. the cam lobes will face backwards and up a little bit when you are on the compression stroke. being on the compression stoke is manditory or you will have all the wrong size shims in place. remember to check the clearance a final time once you have it all back together. good luck!!!!

[Knarf0486]

It's not that I'm an idiot or anything but I was just used to the 400ex way of adjusting the valves. And without the manual I was kinda just diving in hoping it would be a similiar method. Now that I took the head cover off, it all makes sense. I can see all the shims you guys are talking about, etc. The good thing is that after I checked my clearances with the motor at TDC they are dead on. So I'm all set for now.

How many hours does it usually take until I will need to swap the shims?

Thanks for the help guys, greatly appreciated!

[red2004 TRX450R]

there is a trick with the exhaust valves someone on here told me, you dont have to remove the cam carrier. just find something to compress the valve like a 1/4in and take a magnet or something to sneak the shim out and to replace it. (small screw driver with a magnet placed on it works good)

my left side exhaust valve was off so i took an open end wrench and looped a wire around the exhaust pipe stud (about an inch loop) and stuck the wrench through it to get leverage to compress the valve spring down! worked like a charm. just be careful not to damage any thing!!