Author Topic: CB 750 k2 transmission  (Read 1738 times)

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honmac76

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CB 750 k2 transmission
« on: June 09, 2005, 10:50:34 PM »
Hi from Oz,
I recently purchased a CB 750 K2, it is a restoration that has been sitting in someone's shed for 10 years. It is a complete bike, once I freed up the engine, cleaned carbs, points & timing added some fuel and the bike fired up. U beauty I thought, until I jumped on it to take it for a ride.
I have no 4th & 5th gear, 1st,2nd & 3rd are all ok. I pulled the gear cover off to inspect shifter fork and selector drum all looks ok. If I go through the gears when I get to 4th i can sometimes hear it trying to mesh but majority of the time it is another neutral, 5th gear there is no noise just neutral. At times it has gone into gear 4th&5th but not very often.The engine is not running when I have been doing this.
I am hoping some one out there may have some idea what is wrong , I will at least have somewhere to start when I pull the motor apart.
Any info will be much appreciated,
Cheers

Offline bryanj

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Re: CB 750 k2 transmission
« Reply #1 on: June 10, 2005, 02:08:12 AM »
Not something you want to hear but bent selector and damaged gear dogs come mostly to mind
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Spear

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Re: CB 750 k2 transmission
« Reply #2 on: June 10, 2005, 03:45:07 AM »
Honmac. To make it easier for the other Aussies on the site who may be able to help you - where the hell are you?

Offline Tim2005

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Re: CB 750 k2 transmission
« Reply #3 on: June 10, 2005, 12:01:33 PM »
Hiya, unfortunately it sounds probably serious... but just maybe there's some rust or whatever gumming up the gears on the shafts & stopping them sliding along.

If it was mine, I'd take the sump off & get a flashlight & have a look at what I could see from laying underneath it. Work it through the gears too as you look, and turn the back wheel ( just whip the clutch off first to assist with this... after all it's mostprobably going to have to come off now anyway).

Oh, leave the oil draining the night before to keep the drips out of your eyes! You may also find some evidence of the problem in the bottom of the sump, bits of metal etc.

eldar

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Re: CB 750 k2 transmission
« Reply #4 on: June 10, 2005, 01:38:24 PM »
it could even just be out of adjustment. Fairly common on older bikes.