Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: morristhe999 on October 05, 2024, 05:12:13 PM

Title: Heavy clutch
Post by: morristhe999 on October 05, 2024, 05:12:13 PM
Hi everyone
Looking for a little help here I have rebuilt my wifes honda cb400 four, and now she has problems as the clutch is a little on the heavy side.  the cable is good, routing is good and i have fitted on the mechanical clutch pull assist devices - and a dog leg lever but its still a little heavy.
So, has anyone tried lighter clutch springs ?, or a hydraulic conversion ?. I have contacted magura but they dont do one straight out of the box so think it might have to be bespoke. I think hydraulic is the way to go - anyone done this or had it done?

Many thanks

Title: Re: Heavy clutch
Post by: McCabe-Thiele (Ted) on October 05, 2024, 06:57:58 PM
Clutch cables are apparently renown for causing binding needing routine replacement. Are the three ball bearings in the mechanism well lubricated and free of flat spots?
Title: Re: Heavy clutch
Post by: Nurse Julie on October 05, 2024, 07:34:32 PM
Out of all my Honda fours, the 400 was the one with the heaviest clutch. But, even then it was more than manageable, even with little hands. Routing of the cable and plenty of grease on the mechanism definitely helped. After about 100 miles of riding, I used to resort to clutchless gear changes when I could, just to give my hand a rest 😂😂😂
Title: Re: Heavy clutch
Post by: TrickyMicky on October 05, 2024, 11:18:17 PM
My mileage these days is minimal, but I still replace the cable every two years. They sit very close to the cylinder head and gently cook. It's a slow process, and you don't really notice it until you fit a new cable. Absolute bliss!!   On a similar note, my problem is with the return spring on the throttle, ye gods, I'm sure it would keep a barn door closed. Has anyone succesfully tried a lighter spring, and yes, this is with new correctly routed cables.  When I tell my friends about problems with my right wrist allied to those caused by the railway sleeper saddle, they are starting to question my nocturnal habits!!!!!
Title: Re: Heavy clutch
Post by: morristhe999 on October 06, 2024, 10:45:29 AM
Thanks for the replies, everyone, yes new cable but i have not looked at the actuating mechanism as yet so will give that a try later today. Yes the clutch is quite heavy for a bike that is not kicking out massive amounts of powers which was why i thinking of trying to find that sweet spot with other clutch springs between making it easier and not slipping.
Title: Re: Heavy clutch
Post by: 400 Cafe Racer on October 18, 2024, 05:51:15 PM
My mileage these days is minimal, but I still replace the cable every two years. They sit very close to the cylinder head and gently cook. It's a slow process, and you don't really notice it until you fit a new cable. Absolute bliss!!   On a similar note, my problem is with the return spring on the throttle, ye gods, I'm sure it would keep a barn door closed. Has anyone succesfully tried a lighter spring, and yes, this is with new correctly routed cables.  When I tell my friends about problems with my right wrist allied to those caused by the railway sleeper saddle, they are starting to question my nocturnal habits!!!!!

I couldn't agree more Tric,
Before my engine strip, when I disconnected my cable from the clutch housing I tried it for "freeness" by operating the lever and inner cable by hand. The result was VERY high friction and resistance. No matter what I did to try and free it (light lube etc) nothing improved it and it would not operate over its full range without tugging it with a pair of pliers.
My conclusion was that the plastic lining that the cable is surrounded by, had actually patially melted and jammed as a consequence of being anchored too close to the cylinder head and fins by the Honda Guide.

Simple solution: Slide the clutch cable out of the guide and let it sit in its natural position, about 50mm further away from intense heat. No problem.