Topic: 400F tranny...

[Denver_Larry]

I'll be opening up the cases on my 350F anyways, and 400 gear sets seem plentiful and cheap in eBay.  Is this a drop-in swap, or am I in for more pain than that?

[MoMo]

I'll be opening up the cases on my 350F anyways, and 400 gear sets seem plentiful and cheap in eBay.  Is this a drop-in swap, or am I in for more pain than that?

not sure,  350 was a 5 speed and 400 six.  Seems unlikely

[bwaller]

If it was a direct "drop-in" it would have been done already. To know for sure have a 400F complete gearbox (including drum, shift mechanism parts) to compare when your 350F cases are open. From experience I expect your issues may be differences in bearings and very likely shift drum and shift mechanism components and how they attach.

Good luck

[Don R]

 I seem to remember something about the cases being different.

[carnivorous chicken]

Nope, not a direct swap...

[grcamna2]

I hope it fits;they should have put a six in the CB350F from the factory.
I think a couple members here  could measure their trans. mainshaft & countershaft length from where the bearings sit tight against each end for the 400F & 350F;I imagine that would be the determining factor as to whether they would swap.The other thing you probably would have to do is get the Complete trans. from someone including all the shims,etc. You could do a parts-check between the two bikes on an online fiche to see if the bearings,etc. are the same,that's where I'd start.

[MoMo]

I have a spare 400 four trans complete.(most everything I have is spare as I rarely use any of it-and it all is for sale).Larry

[bwaller]

Some machining can make it fit in the cases. It's to get a look behind the clutch basket, shift mechanism, mainshaft length, clutch. No way it's an easy mod BUT where there's a will!! Been there done that.

[Denver_Larry]

Some machining can make it fit in the cases. It's to get a look behind the clutch basket, shift mechanism, mainshaft length, clutch. No way it's an easy mod BUT where there's a will!! Been there done that.

Thanks, I may save that as a future upgrade then... Or just find a complete 400F engine to rebuild...

[Flyin900]

I would question the ability of the 350's tiny output to be able to deal with a 6th gear too.
Honda listed the HP in the low 30's and there is very minimal torque, so a extra gear on that motor would be iffy at best.

[grcamna2]

I think a 400F motor in a CB350F is a Great upgrade for it !

[bwaller]

Flyin900, more tighter gear selections helps small engines, instead of wider spaced, fewer gear option gearboxes.

One example...Honda's own RC112 (50cc twin) with a 9 spd box. OR Suzuki's RK67 with a 14spd. 

[grcamna2]

Flyin900, more tighter gear selections helps small engines, instead of wider spaced, fewer gear option gearboxes.

One example...Honda's own RC112 (50cc twin) with a 9 spd box. OR Suzuki's RK67 with a 14spd. 

What's "Flyin900"  Brent?

[bwaller]

That's the fellow's handle 3 posts up!

[grcamna2]

That's the fellow's handle 3 posts up!

oops  it comes from not wanting to look backward much,sorry

[camelman]

While you have your trans apart, check the bushings on first gear. They often wear out and create difficulty shifting. You can quickly check by feeling for wobble of the gear on the shaft. It's an easy fix for a machinist to press out the worn bushing and replace with a new one. The machinist will have to make the new bushing.

[Denver_Larry]

Thanks for the tip Camel..