Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: taysidedragon on October 20, 2025, 05:54:33 PM
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I'm having some problems with my gear changes and finding neutral when my 400f engine is hot. Cable is running free and adjusted correctly at both ends.
I know that the clutch lifter mechanism has some wear. The 3 ball bearings will fall out of their cage until assembled. Could that be causing the problem or is it something more serious?
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Could be too thick oil or grooves worn in the clutch basket fingers, the latter allows the fingers on the clutch plates to settle in them rather than separate fully once the spring pressure is released
The poor man's solution was to dress any grooves or notches with a fine file.
If you search for clutch basket grooves you will see what to look for.
If you have it running on the main stand in first gear, can you stop the rear wheel rotating easily with your boot when the clutch lever is pulled in?
Regards
Dave
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It's not uncommon for all Honda CB SOHC 4'S to be tight, if not impossible to get into neutral when stationary when the engine / gearbox is hot.
My clutch/ gearbox, cables etc were perfect on Hettie, my 400/4 but after a thrashing she was impossible to get into neutral, either from 1st or 2nd. I just click into neutral whilst still rolling to a stop. I still do that on my 500 and 550.
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Ok thanks. Good to know. It didn't used to do it though.
Will check the clutch basket.
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Definitely not an unknown characteristic!! On my 400, I have no problem selecting neutral at standstill, on my GB250, as soon as it reaches running temperature, forget it!!! Both are adjusted in the same manner, and both are running on 10w 40 mineral oil. Occasionally on the 250, I have had to kill the motor, select neutral, then re-start. Any body who can remember the original Mini's with the A series engines can tell you that when the engine was cold, the gearchange was wonderful, but deteriorated as it got hotter. One of the disadvantages of running a gearbox in engine oil instead of a nice gloopy EP80 or 90 gear oil.
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When my CB350K is very hot, it creeps along a tiny bit in first gear, and I have never been able to adjust that away, just have to try to select neutral on the move in anticipation of a stop. A design fault I think and somewhat related to the material used in the clutch pushrod. I know these changed with later models but the problem was never fully resolved.
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There's basically problem with this type of operation, in that the cable operation inclusive of the mech to 0ush the clutch, can in no way compensate for the engine and clutch components dimensional change through heating.
This will be amplified, if there are in existence, any non planar clutch plates in the pack. Wonky or distorted, in other words.
You can try adjustment of the cable when hot, which should ease the neutral selection .... but it should then be very marginal and likely slip when it's used cold. This can't adequately be resolved.
Any accumulation of "slack" in the lift component train adds to the inability to lift the plates apart sufficiently when that "pack" dimension is hot.