Topic: CB500 four k1 - 3rd gear issue

[HondaMan]

also check the shift drum sideways movement,this was improved on the 550s with a different locating mechanism,if the drum can move sideways it takes the fork with it,heres one i prepared earlier!

Hey, Dave: is that one of those new lightweight dragracer gears?

[dave500]

sure is Mark,its the 11,000 rpm test!

[bryanj]

Aah the crunch testing result

[dave500]

that was few years ago,popped out of third couple times under load on a long ride,made it home with no 3rd,found the three lugs in the bottom of the pan,couldve been way worse result?

[HondaMan]

that was few years ago,popped out of third couple times under load on a long ride,made it home with no 3rd,found the three lugs in the bottom of the pan,couldve been way worse result?

Boy, that was LUCKY!
A 750 I once fixed broke off one of the C5 dogs and it flipped up on top of the whole shaft, then right in between the gears. Made a nasty mess.

[dave500]

yeah i escaped a long skid rear wheel lock up or two shafts being pryed apart splitting the case where its never been split before?

[bryanj]

Dave, you were lucky. Thats one of those things i have heard of but never seen in person, loads of knackered centre selectors though

[dave500]

this was actually a 550 motor!

[bryanj]

For some reson the 550 sheds dogs way more than the 500

[Oddjob]

The right hand selector is toast I'm afraid, it's also hard to find and bloody expensive when you do find one. 24211-323-000 BTW.

There is a witness mark on the left hand selector as well, not a big one but sometimes not right in the gearbox when they occur. 24213-323-000 You may want to consider changing that as well.

Oddly, the centre selector isn't that bad, it's normally that one which wears away faster than the others. As explained it's a CL350 part number, I do happen to have 2 NOS ones, I also have a NOS left hand selector but not a right, never found one going cheap enough to tempt me.

I also have a complete NOS gearbox, every gear, thrust washer, circlip, bearings and shafts, been collecting these for some years and finally found the last gear I was missing last year, not sure yet if I'll fit it in my restoration this year but may not if the old box still looks ok.

One of the pics shows mainshaft 2nd and 3rd gear, it's the one where the middle selector is fitted to it, what's concerning about that pic is the engagement slots on mainshaft 4th gear, that's the one right next to the fixed gear on the mainshaft, so closest to the clutch, the slot looks shiny, like something is wrong, there's also what looks to be a small sliver of metal sticking to the gear. I'd check that if I was you.

Has the box been apart before? might be that someone assembled it wrong, it's easy to orientate some of the thrust washer wrong and the circlips are meant to be fitted a certain way as well.

As Bryan says, there is a firm in Italy making really fantastic copies of the selectors, they are better made, have harder tips so should last longer and the finish on the surface of the selectors in just ace. Not cheap though, I bought all 3 in 2022 and the cost then was 150 euros for each selector, 300 for 2 but an offer of 400 euros for all 3 plus postage.

Pic of the middle selector compared to a NOS Honda one.



You need any details PM me.

[HondaMan]

The right hand selector is toast I'm afraid, it's also hard to find and bloody expensive when you do find one. 24211-323-000 BTW.

There is a witness mark on the left hand selector as well, not a big one but sometimes not right in the gearbox when they occur. 24213-323-000 You may want to consider changing that as well.

Oddly, the centre selector isn't that bad, it's normally that one which wears away faster than the others. As explained it's a CL350 part number, I do happen to have 2 NOS ones, I also have a NOS left hand selector but not a right, never found one going cheap enough to tempt me.

I also have a complete NOS gearbox, every gear, thrust washer, circlip, bearings and shafts, been collecting these for some years and finally found the last gear I was missing last year, not sure yet if I'll fit it in my restoration this year but may not if the old box still looks ok.

One of the pics shows mainshaft 2nd and 3rd gear, it's the one where the middle selector is fitted to it, what's concerning about that pic is the engagement slots on mainshaft 4th gear, that's the one right next to the fixed gear on the mainshaft, so closest to the clutch, the slot looks shiny, like something is wrong, there's also what looks to be a small sliver of metal sticking to the gear. I'd check that if I was you.

Has the box been apart before? might be that someone assembled it wrong, it's easy to orientate some of the thrust washer wrong and the circlips are meant to be fitted a certain way as well.

As Bryan says, there is a firm in Italy making really fantastic copies of the selectors, they are better made, have harder tips so should last longer and the finish on the surface of the selectors in just ace. Not cheap though, I bought all 3 in 2022 and the cost then was 150 euros for each selector, 300 for 2 but an offer of 400 euros for all 3 plus postage.

Pic of the middle selector compared to a NOS Honda one.



You need any details PM me.

Wow, those are nice parts!
I'm about to tear into a well-used 500 engine for the book. Maybe I'll try those if it's buggered up?

[Oddjob]

It's also the tactile feel of them Mark, like stroking wet velvet.

If you need a NOS selector for the rebuild let me know, you know where I am.

I'm also in possession of the biggest stock of 500/550 main shell bearings in the world I reckon, well over 100 black shells alone, even have some yellows and a few greens and browns although I'm not selling them yet. When the average price goes over £30 a shell I'll sell what I don't need. I'd make an exception for you though Mark if you needed any.

[HondaMan]

It's also the tactile feel of them Mark, like stroking wet velvet.

If you need a NOS selector for the rebuild let me know, you know where I am.

I'm also in possession of the biggest stock of 500/550 main shell bearings in the world I reckon, well over 100 black shells alone, even have some yellows and a few greens and browns although I'm not selling them yet. When the average price goes over £30 a shell I'll sell what I don't need. I'd make an exception for you though Mark if you needed any.

Wow, thanks, what an offer! If I get in that spot, I'll drop you a line.
I'm working (once again) on the 500/550 book, got a 500 engine finally so I can make the required pictures. I haven't decided yet on whether I will put the 500 and 550 'sections' of the Tranny work in the same chapter, or separate them: I tend to think there's enough difference between them that having separate chapters may be wiser in the long run to prevent confusion for the newbie using the book. They are so different as to be fully separate engines behind the crankshaft, IMHO. Forward & above of there, they aren't much different, side-by-side.

[bryanj]

Just to confuse it more a couple of gear clusters are the same 500 to 550