2nd Shot 6?

[johno74]

Been offered a k reg CBR600 which jumps out of second gear. Cheap.

I've presumed its a complete motor strip down but is it an easy job? What about the worn dog-are they easy to replace?

Is there anything else thats worth looking at while its all over the kitchen floor? Cos these motors are pretty tough arent they?

Or Is it worth just getting a new motor? As long as that doesnt jump out of 2nd as well.

Anyone know?

ta

[Grav]

I replaced 2nd gear on a ZZR600 a few months ago, Johno. I just took the bottom casing off after turning the engine upside down, so it's not too bad a job, but it can be an expensive one.

Swapping the gears is the easy part as long as it goes back together in reverse order to how it came apart. Just lay the parts out on a clean surface and you're laughing.

It cost just under £400 for the ZZR I did for my mate and that was using genuine Kwak parts throughout. I imagine the CBR will be a similar expense and really does depend on how much you are willing to spend considering the condition of the bike, it's potential re-sale value or if you really want to keep it. A replacement engine will probably cost around the same, but with no guarantee of it not having the same problem cos CBR's get well and truly thrashed.

[trikerdrew]

on how cheap?No I don't need to know,probably make me feel green.

Complete non running motor off e bay could sort it.Or just a gearbox if your lucky.

Grav is spot on.Flip motor,split cases.Easy and quick.

Easy way to turn a dollar.All power to you

Good luck

Drew

[johno74]

Thanks for that.
I was wondering if you could get to the gears etc from the underside. No point wading in from the top down if its not necessary.

Any recommendations for good new parts? Good as in at least vaguely reasonable prices..?

cheers

[Grav]

Try this feller,

http://www.davidsilverspares.co.uk/

[johno74]

Just taken the gear drum and the selector forks out but the damage is not what i was expecting:

the 3rd slot in the drum, which is furthest from the clutch has a couple of chips out of it
the fork from that slot ie the left fork has had one side ground down..

I dont see how those would make it jump out of gear?

Does this damage ring any bells with anyone=especially as its about £350 to replace

ta

[Grav]

Yep, its been thrashed.

The chips missing from the drum coupled with the wear on the fork means the cogs dont quite mesh properly and it will not stay in gear. It's not the individual bits of damage that matter here, its the accumulation of each bit put together that gives the problem.

The only fix is to replace each part that's damaged, the drum, fork and the cogs. Miss one bit out and the problem will re-occur within a very short time. Do the job right and the gear box will last a lifetime if it isn't thrashed.

[Zaphod]

replace the selector, the gear it moves and the gear that it engages with (worn selector direction).....

had a similar problem years ago on an old 750/4, just replaced the selector to start with .....

a week later i did the job properly (had to) :D

[trikerdrew]

In Ad-Mag it's in Notts if that's any use

drew