smallest shim to small?

[rollie]

my quad has been hard to start recently, i took it apart to adjust the valves, by doing the math i need a 1.09 shim on the intake valves, and the smallest they make is 1.20. my exhaust valves are perfect. IF i bumpstart my quad, it runs 100%, and once its hot it will start 1st kick every time? any ideas? thanks

btw yes i do have bigger exhaust valves and they have been cut, 2 seasons ago and it has run/started perfect then till a few weeks ago

[mx Eli]

i'v heard of people fileing them down a small amount

[eastside 400]

what has happened is that the valves and seats have worn past the servicable limit, between cutting the seats previously and then now wearing out again they are past the point. Some people do file down the shims to get some more time but its a band-aid, also you have to be careful because now that your valve sits higher in the head, the installed length of the spring is bigger meaning you have less spring pressure. The correct fix is to get new seats and valves installed.

[DnB_racing]

you might get lucky if you keep clean oil, and a freshly cleaned and oiled air filter,and good gas, it could just need new valves,

even if everything is kept pristine the valves will still cup after time,

i wouldn't run much longer, you definitely run the risk of the valves slapping

right now you might get away with only replacing valves, if you keep going you will definitely need head work also.

IF.... you dont need to have the head done YET, if you keep riding with less spring tension, and bad valves, you will definitely mess up the head if it already isn't..

pull it as soon as possible, if money is an issue,

[hrc450er]

When i had my seats cut i was on the smallest shim to start with so i took the buckets and milled off Bout 20 thousandths on the inside nub and that gave me alot bigger shim to work with. I didnt like the idea of filing on the valve

[coryatver]

you need new intake valves. They have wore down so far that you are out of adjustment. On 06+ 450rs they are titanium they wear crazy fast I have to adjust mine ever couple races and go through at least a set a season.

It starts when hot becuase the metal valves expands when it is hot giving the valves some clearance so it will start.