what size?

[QuadRacer18]

alright guys, i found my feeler gauge and i measured my exhuast valves, they are both at .011 so they are right on spec. now the quad will not fire and after measuring the intakes i couldnt even fit a .003 in there let alone a .006. Now this quad has never had shims changed, i know engines vary but is there a ball park estimate on size for these stock shims so i know how much bigger to go, and do trial and error? I would measure it but i dont have a micrometer.

so if it wasnt clear, my question is about what size intake shims are used when put in from the factory? And, what size would you reccomend starting at? take into consideration that the .003(lowest my gauge goes to) did not fit. thanks for answering all of my shimming questions!

You need a valve job. The intake valves get sucked into the head. I had the same problem. I went with Kibble White valves and all stock Honda parts. I did the piston and timing chain while I was there. I forgot how easy it was to start.

[QuadRacer18]

i got it to fire using starting fluid so i know the valves arent sucked into the head, ive also checked them and they look fine mechanically. anyone know what size shim i should start with?

EDIT: im still almost positive i wont need a valve job, but if i did what parts would i need to buy? valve seals, valves and valve springs, is that alll?

You need a valve job. It is a common problem with the hHonda TRX450R. CRF450R and the CRF230F. The valves get cupped where they seat in the head. That in turn pulls them up into the head making them so tight that you can't shim them and they are open all the time. that is why you can start it hot or start it with starting fluid. You can probably start it by dragging it with another quad. I know I went through it already.
You need 4 Kibble White stainless steel valves and the rest Honda parts.
Valve seals
intake springs
all lower seats
keepers
gaskets
I did a piston and timing chain also.
Good Luck

[QuadRacer18]

can i go with honda valves, i would rather leave it all honda parts and order from service honda to save money.... also, if i pull the head off will i be able to tell that this is the case, will the intake valves be open? what is proof that thats actually what my problem is? I beggining to doubt weater i fit the feeler gauge under the cam and measured right. let me know... i just dont want to be spending money where its not needed unless what you say has happened actually did happen. thanks

You can use what you want. I gave you what will be the best for long term use. Like I already said, if you want to believe it or not, bottom line is you need a valve job. I have been doing this a long time. I know you don't know me personally but that all I can do to convince you. I'm done here.

[QuadRacer18]

i appreciate your help, dont let it come off the wrong way. Now, what parts is worn out, is it the springs basically.... im just curious to know what part caused the problem, and my only guess is worn out valve springs?? thanks again for all your help

The valves wear, that's why you want to go with the Kibble White valves. The intake springs get stretched. Have someone qualified look at the parts to determin what you need. The norm is the stuff I listed earlier. Hope I help out.

[rlplive]

for future reference here is the shim formula
For your new shims: A = (B-C) + D A = New shim thickness B = Recorded valve clearance C = Specified valve clearance D = Old shim thickness