Honda Twins banner
1 - 6 of 6 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
Picked up a barnfind 1973 CB450 that sat for many years in a barn. The shifter can physically move down, but has zero give when trying to push it back up into neutral. I got the bike running, and drove it around the yard in first, and the clutch free'd up, so now it's easier to move. What might this problem be, and are there any good threads/ videos on fixing it? I'm thinking a bent shift fork but I figured I'd let some other people weigh in. Engine sounded healthy otherwise. Thanks.
 

·
Registered
Joined
·
203 Posts
Would need a parts blowout, but sounds like a broken spring at the shift shaft arm. It's a claw that pulls and pushes the drum. When the spring breaks, arm falls down, no longer can shift the drum back to N or second, but stuck in 1st when you bought it, thus it was parked, not repaired.

That might mean hand tracing out a paper gasket if not some aftermarket gasket maker took on making a set. Matching a spring. So that means clutch assembly, center bolt off the main shaft, then the clutch center, then the big clutch outer, then you have access to the shift arm.
 

·
Registered
Joined
·
1,475 Posts
You know of CMSNL.com and partzilla for the exploded views and component pictures, not to mention part numbers and price.

A manual will also help.

If clutch cover gaskets are unavailable ( which I doubt ) then make your own.

Gasket paper is available as are wood drills with a self centre "spike"...

Don't be tempted to use sealer on clutch cover gasket, or anywhere else really apart from c/case top and bottom half where they join.

Do your research before "going in".

You will need the peg spanner for the centrifugal oil filter "can or drum"...

I assume you have the bike on centre stand, engine running and trying to select neutral
 

·
Registered
Joined
·
166 Posts
Picked up a barnfind 1973 CB450 that sat for many years in a barn. The shifter can physically move down, but has zero give when trying to push it back up into neutral. I got the bike running, and drove it around the yard in first, and the clutch free'd up, so now it's easier to move. What might this problem be, and are there any good threads/ videos on fixing it? I'm thinking a bent shift fork but I figured I'd let some other people weigh in. Engine sounded healthy otherwise. Thanks.
Hello, something has broken under right side engine cover. I you plan to work on your bike start with a complete gasket set and an oil seal kit. Then you have all the gaskets needed (O-rings too) to repair anything. Don't reuse gaskets, don't use sealer. When engine covers are removed change the seal, it's much easier with cover removed. "4into 1" web site in SFO is good for many CB450 parts. Post some photos so we can see what you're working on.
Good Luck, HondaJohn
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #5 ·
Would need a parts blowout, but sounds like a broken spring at the shift shaft arm. It's a claw that pulls and pushes the drum. When the spring breaks, arm falls down, no longer can shift the drum back to N or second, but stuck in 1st when you bought it, thus it was parked, not repaired.

That might mean hand tracing out a paper gasket if not some aftermarket gasket maker took on making a set. Matching a spring. So that means clutch assembly, center bolt off the main shaft, then the clutch center, then the big clutch outer, then you have access to the shift arm.
Hello, I had the side cover off and saw that the spring seemed to be intact and in place, I’m assuming at this point it’s a bent shift fork?
 

·
Registered
Joined
·
203 Posts
I don't know about bent, but say you take a phillips screwdriver to the drum and turn it that way. This overrides all the linkage and directly shifts the forks. Easiest way is to have the back wheel off the ground and move the wheel up and down so as to sync dogs into their slots and you turn the drum in both directions.

Screwdriver should be effortless as far as turning the drum. Then with the cover still off, install the shifter and shift it to first and back to N. If it's again, effortless to spin, might the shifter be bent getting the cover off? Shifter hangs up thru cover, not the spinning drum being smooth and all that kind of movement?

Kind of hard without hands on/test ride.
 
1 - 6 of 6 Posts
Top