Safe shimming?

[GTXR]

I know I need vavles!!! Already have intakes and spring kit, just waiting to get piston/cam chain etc. Now my first time shim I went from 1.7mm shims to 1.6mm and then 10hrs later down to 1.5mm on the left intake. Now question is how safe is it to keep shimming?? Im hoping to get another couple rides in and going to check them again after my last 3hr ride. If the left intake or either have moved again? Is it still OK to shim one more time before rebuild? Will the valve live or break etc. Any advice would be greatly appreciated!! Or expreriance as well. Yes its coming apart soon, but will it make it till the snow flies?? Thanks guy's!!!!!

[MELK-MAN]

once you zero out, it just won't start.. so that would be that ..

[GTXR]

HMM thats funny. They went to basically Zero spec the first time i shimmed them. .001" then shimmed 10hrs later and moved again to .002" shimmed again. Never had any issues with starting etc? Just checked them tonight and the left intake is at .005" from .006" after 3hrs. So My question is!!!!! Should you worry about shimming? Until you get to the smallest shim?? Or do the valves before that???

[mxscotty]

I'm pretty sure you can safely shim them until you've run out of clearance with the thinnest available shim in (1.2mm)

When's the snow due?

[iason755]

With zero left intake bike started normally .

I have put new intakes valves starts again normally.

Weird but true.

[motoxracer476]

I think u can just shim them till u run out of sizes also. The reason that the bike becomes hard to start once at zero is because the valves cannot close all the way causing loss of compression.

[oakhillbiker]

when they zero out they will bounce "float" and beat the sh!t out of the valve seats alot faster best to not let them zero watch this video

[GTXR]

Cool video. Im not planning on running it down to the smallest shim just another couple rides etc. Snow will be in about a month. Normally that is. I dont want to have to replace the seats in the head though either. Maybe just one more ride and Ill call her done? thanks guys!!

[MELK-MAN]

didn't watch the vid yet, and yes, stronger valves help with valve fload when your running heavier ss vs ti intakes (more than 15grams heavier) but that has nothing to do with zero valve clearance. zero valve clearance.. if the motor would run.. your valve seats would last forever as the valve and seat are barely touching or not touching at all. THAT is why the bike gets hard to start when you are zeroed out.. loss of compression. Zero or worse valve clearance isn't refering to the seat to valve, its the rocer to bucket clearance. It has constant pressure holding the valve open or near open all the time.

After 800 hrs on an original 04 head with MANY valve adjustments, and multiple sets of intakes i got this one down brother! hard starting is the classic sign this is becoming the issue if the bike had been starting easy to that point and has a good number of hours on it.

[GTXR]

Ok great explanation Melk-Man! How were the seats in that head when you had to do the valves the first time?? How many times did you shim them before the top end job? I going out on a limb but I think I should be ok for another ride or 2 and then pull it apart??

[MELK-MAN]

Ok great explanation Melk-Man! How were the seats in that head when you had to do the valves the first time?? How many times did you shim them before the top end job? I going out on a limb but I think I should be ok for another ride or 2 and then pull it apart??

bro, i put 6 hours a week on my bike between single track and faster harescrable type trail riding. Even zeroed out, i would kick that thing for 20 minutes if i had to to get it started, i wanted to ride.. (just don't stall that bitch in the woods..)

got this machine back sometime in 05. Rode about 9 months before needing work done, and right away (as i didn't get it new) had the seats cut by a local guru around here in FL.. Baybor. From there it was like clockwork. Ride a bunch, shim. Ride a bit more.. shim. Ride a LITTLE more, zero clearance and intakes were junk. Did this routine for 3 almost 4 years??? (holy cow). Then earlier this year rather than mess with the crap seat material any more on the 04 head, went to a newer 06-08 head (i went with the 08). Put about 100 hrs on the bike and still no movement in the valves but everything was brand new.. I suspect as the seats get some wear I will see shorter intervals until needing an adjustment, but nowhere near as frequent as the older head.

SO.. don't sue me if yours blows, but im guessing you would be JUST fine riding a bit more.

[GTXR]

No worries and greatly appreciate the info!!! Just what I was looking for etc. Thanks again Melk-Man and keep riding!! Wow you put alot of time in?

[MELK-MAN]

No worries and greatly appreciate the info!!! Just what I was looking for etc. Thanks again Melk-Man and keep riding!! Wow you put alot of time in?

.. just got back from another 1.5 hrs. Nearly 5 gal of fuel used since Sat. afternoon!

No problem. I don't know as much as many on this site, but some areas of the machine i have become rather profecient.