Valve Clearances Shim Size Issues

[thomp1983]

Evening, have been looking at my valve clearances whilst reassembling my engine and have ran into another issue, after measuring the shims they range in sizes from 3.52mm to 3.74mm and after checking nearly all clearances are too big which would require even bigger shims fitting but from looking at the microfiches the shims i currently have are all bigger than those kawasaki list so i can't understand where they've come from or where ill get some even bigger ones to bring the clearances into specs anybody got any ideas as to whats going on and how to fix?

cheers
chris

[RedexRobB]

I assume you are measuring the shims using electronic vernier calipers? iirc they should come in 0.05 increments so i suspect youve measured something wrong.

I also assume you are using feeler gauges to measure the gap in mm, not inches??

[thomp1983]

valve clearances measured in mm (checked feeler gauge with vernier) and shims measured with a micrometer which is known to be accurate that measures in 0.01mm increments so fairly sure the measurements are right. a look on google shows one thread on visordown where a zxr400 owner had had a bike with cams reground for performance that he was unaware of that used bigger shims but it never got concluded so don't know how they found out the cam had been reground or where they sourced bigger shims

chris

[thomp1983]

turns out after a closer inspection and hunt about i have kent cams fitted, there stamped kc kaw15 1093 on the pulley end, ive emailed kent to see if they can supply shims. would having these cams fitted affect my idle at all as it's from a non stable idle that has led to me having a stripped engine. also i assume the engine will time up as normal (the pulleys are fixed non adjustable) and with it having uprated cams i don't want to be retarding the inlet cam by a tooth to improve midrange?

and back to setting valve clearances, i assume if my shim is 3.50mm and the clearance 0.30mm and i want it to be 0.15mm then i would need a shim that would be 3.65mm?

cheers
chris

[richr]

sizes sound good to me

gap too big bigger shim needed gap to small smaller shim needed

if the cams are re worked then you may get a lumpy tick over depends what has been done to them

[RedexRobB]

Could be that just the carbs need balancing?

I think also, if its got kent cams in it, then the standard valve clearances may not apply?

[thomp1983]

i had rebalanced the carbs before stripping it but it didn't fully solve the issue. the strip down came about because a spark plug sheared off so i had to remove the head to remove the rest of the plug. the clearances for kent cams are inlet 0.15mm and exhaust 0.20 so pretty much as original. i ordered the 6 new shims i needed today they were £4.25 each and i should have them next week, the rest of the clearances could be brought into tolerance by swapping other shims around, the spare shims i have i will make available to zxr world once ive got my bike sorted.

chris