I just got a 78 honda cb750/4 theres lots of info out there but I am having trouble identifing cyl #1 is it the left or right side as you are sitting on the bike. Also what is the best way to set the valve tappett clearance.
Thx in advance
Cylinder 1 is to your left as you sit on the bike and unless i miss my guess firing order is 1342.Valve tappet clearance is .002 to .005 of an inch and is measured at the base of the cam lobe.You will need to remove the cam cover and you can either remove the left side ignition cover and turn the crank with a 12mm socket and ratchet or just bump the engine over with the starter.If the clearance is too loose you will have to find the feeler guage that slides in with a slight resistance then remove the shim and measure it with a micrometer and add the amount needed to your measurement(if this needs more explanation let me know). Some dealerships will trade you 1 for 1 on shims but if yours won't then it could get expensive as stock shims cost around $8 a piece. If clearance is too tight (as in no clearance) it's a crap shoot and you will have to remove and measure the shim as before and just keep installing thinner shims until you find the right one. Be aware that this can also mean the valve stem has stretched slightly or the seat/valve face is worn and could cause bigger problems down the road. Since the buckets on these bikes are mechanical (not hydraulic) it is important to keep them adjusted properly to avoid hanging valves and embarrassing noise.There are manuals available on this forum and i highly recommend you go download yourself one.
One other thing, DO NOT rotate the cams with the shims removed. You will damage the cam lobes if you do.