Doing the clearances - MC19 CBR250

[aer0]

Hi all,

wondering if i could get some guidance here.

I consider myself ok behind the tools, kinda know what im doing and am a pretty good learner.
I have been doing basic things for years but figure things like valve clearances cant be too hard as i keep seeing people talk about how they do them in an afternoon kinda thing.

oil/filter/sparkplug type stuff is easy as so i figure i can make the step up.

ive got a maintance guide for my bike that has general specs and lists
Valve Clearances (COLD Engine, i.e. leave engine overnight)
Inlet valves : 0.16mm  0.03mm
Exhaust valves : 0.23mm  0.03mm
its got a whole bunch of other specs and stuff but i figured thats the numbers i need for the valve clearances

also seen it mentioned that "balancing the carbs" might be another thing to do... i guess the least they could do with is a cleanup after 20 years of sucking gas

Can anyone recommend any tutorials online for doing this?

i know its a little cheeky of me to ask but if there is anyone local that might be able to show me around it all im more than happy to provide beers/wine

[bsasuper]

Dont forget when you check the valve clearance's, if any shims need changing they are expensive, some shops want $20 per shim, sometimes you get lucky and can just swap them around to get the correct clearance.You can buy a shim kit, not sure what the price is now, i paid $250 a few years ago and have used it many a time as the same shim type is used on more than one make and model.

[hmmmnz]

yeah thats the pickle about shimmed bikes, the cost of the damn shims,
normally the clearances become less, so you can( but not recommended) sand down the shims to the correct thickness, its hit or miss, and you have to sand them down completely flat and be accurate (micrometer accurate)
some shops will do a swap with old ones they have, but generally you have to give the mechanic a hand job to get favors like that
and its a bugger if you dont have any other transport and have to re-assemble the bike to go and buy the shims

tip, before you remove any shims, write down the clearances for each valve
draw a little picture of their location, and then pull the shims out 1 at a time and record the size of the shim next to the clearance of that particular valve,

the last thing you want to do is have to re-assemble it all again just to find the clearance,

once you have both clearance and existing shim size then you can work out what size you need to put in there. you should be able to swap around a few of them, but never all of them,

as for balancing, also an easy job, very very easy compared to shims

you need to buy or make a balancer though heres a pic of what i make, takes all of 10mins

and works a treat, remove the caps on the vacume nipples and connect, start from the center carbs and work out, balancing as you go, (some bikes you balance from 1 side to the other, you'd just need to check the screws and see how it works)

have fun

[aer0]

Thanks for the adviec hmmmnz looks like im going to have to do a bunch more reading before i start ripping into all of this i still have to get a complete understanding of how it all works before i just jump in.

[hmmmnz]

if you want to come over one night or in the weekend ill talk /show you through it.

[The Pastor]

Try cbr250.com

[aer0]

Try cbr250.com

yup have been reading up on there too, unfotuntaly not many locals on that site that could help easily but good reading all the same

hmmmnz i might have to take you up on your offer some time. some help would be choice

[hmmmnz]

no worries,
would be handy if you could get a selection of 7.5mm shims,
looking at the manual, its not a job you want to do twice
(very similar to the old zxr750 setup. cams out job )

[The Pastor]

no worries,
would be handy if you could get a selection of 7.5mm shims,
looking at the manual, its not a job you want to do twice
(very similar to the old zxr750 setup. cams out job )

you have to take the cam gears out to do the valves? oh man!

[hmmmnz]

yeah it has buckets over the shims, in order to get the buckets out, the cams have gotta come out fun times,
the h1 and h2 zxr750's have the same set up, later on jkl models they have the best shim system ive seen yet, all you do is shift a rocker type arm over to the side and then you have complete access to the bucket and shim, thats a 10 min job, such a pleasure when its that easy