how can i check the shims without taking the cam chain out, or, do i have to take it out? and how do i know if i need shims and what size to go to, i have just done a carby clean fzr250 2kr bds28 now it won't start and backfires thru the carbs while i,m cranking the motor the only thing i haven't looked at is the shims and by looking at the head (have an old head hanging round) looks like i may as well recondition the head if I have to break the chain and take the cams out, as i'll have to get a new link (depending on price may as well replace cam chain) cam cover gasket(seal) radiator have to come out so may as well replace thermostat and hoses and O-rings, head gasket and no guarantee she'll start (looking at this list I may as well get a new bike and chuck this one ) sounds like a lot of work just to replace shims just found daves article on valve adjustment but doesn't say what the size shims should be when replacing EDIT 11/04/012,..Just reread Daves article and found the clearances i need, and spoke to a mechanic today 11/4/ and told me which way to read measurements taken (no gap smaller shims) now where did i hide those feeler guages?
Hi, Johnny. The chain doesn't have to be cut, but the tensioner has to come out - that'll give you enough slack to pull the cams. Use a wire hanger to secure the chain so it doesn't fall down inside. The rad doesn't need removing, just unbolt it - the hoses have enough play. The head gasket should NOT require replacement, nor the hoses, orings or thermostat. The valve cover gasket is reusable (unless it's perished). As to what shims you'll need, this is something that can only be determined by first measuring the clearance, then noting what the current shim is. Do the math to establish the correct shims to adjust the clearance. Download the 400 manual. This isn't a HARD procedure, but it is involved, and you have to get the valve timing RIGHT to avoid rapid and massive engine damage.
not having played with this type of engine b4 especially twin cam, was not sure of the procedure but most will come off just to renew some parts to be on the safe side knowing those are not going to give me problems too soon thanks
When doing the shims it is most essential not to mix the the parts up, including your shims until you are double sure of the sizes and have everything written down.. Sometimes the shims have no marking as to their size. I have a dial caliper (old school technology) to measure them. Nowadays you can get digital calipers. Don't take out the cam followers that are within tolerance. Everything goes back exactly where it came from except the shims that you have to change. I found it was the only inlet valves that had worn and needed different size shims. Hopefully it will all work out for you..
thanx buddy was going to have a go today but pissing down rain at the moment if it doesn't ease over the weekend probably next, was even going to do some airbrushing but thats out too. oh well sunny queensland
