Is this a genuine clutch lifter push rod mod or what...

[simonster]

I have a 500 k1 with a push rod in two parts from the clutch adjuster to the clutch plate lifter,approx 4 inch and 6 inch lengths with tailored ends no burs. I know the parts book shows one piece. Is this a later mod or has the previous owner adapted two to save on the cost of buying a replacement. If so what are the con's of this set up. The clutch seems to work OK without any engine load but haven't ridden it in anger yet. The engine is on the bench at the moment so probably the best time to replace it depending on the advice?

[s7paul]

I'm pretty sure they were all one-piece items.  The usual reason for a two-piece pushrod is that it's broken.  I don't see why anyone would have done it intentionally.

[mickwinf]

yes should be in one piece, quite hard to find now as not available new, could probably make one out of some rod.

[SteveD CB500K0]

I remember discussion on this on .net

Ah, here it is (I wrote it up as a FAQ)

http://forums.sohc4.net/index.php?topic=369.msg949314#msg949314

[SteveD CB500K0]

Here's the text (Shifter19 and Number13 are the members on .net who actually did the work):

As of this writing, CB500 clutch push rods are pretty much impossible to find anywhere. They come up on Ebay every now and then but sell for $50+.  That's just stupid for something that may well break again...

So, between Shifter19 and Number13 (seeing a theme here?):

Measurements for a Honda OEM pushrod are:

10 1/8 inches or 257 mm long
3/8 inch in diameter or 9.5 mm

You can easily fashion a push rod from
3/8" steel rod found at any hardware store.
The shifter side end should be ground flat and square,
and the brake side end should be neatly rounded in a semi-sphere
to mate with the clutch basket. If you err, err on the side of a bit too
long since this will allow you to keep the lifter mechanism low and avoid cracking.
May also be a good idea to quench harden the ends.

[Trigger]

I am interested in the push rod at the right price.

[Woodside]

Hi I had a similar problem but I bent my rod.
.....our friend Bryan helped me out and I made another one.
I think if I look I might have another one as I made a couple from stainless ...
.or at least the specs of a new one ...the hardest part was getting the domed end to marry correctly so as not to jam in.
But at the end of the day it's just a straight piece of rod.   
I believe some people,put a small ball bearing in the middle to aid or even repair the rod?
Details are here
http://forums.sohc4.net/index.php?topic=118045.0

[Bryanj]

What happens is if you let the chain get very slack it "whips" off the gearbox sprocket on the over run and whacks the rod breaking it just inside the seal/bearing. If this is what happens the piece is too short to use a ball bearing between the two as the short piece waves about and makes the seal leak. If you could have two identical pieces a ball bearing would work fine

[simonster]

Thanks for the replies. I have removed the two pieces which measure 7.8 mm diameter by 255 long, which is way off the width suggested by steved of 3/8 inch or 9.5 mm. I have used manual vernier and may be a point or two of a mm out but even with my eyes can't be that far off. This rod is sub inthe oil seal and lifter plate on the basket side so iI'm happy the rod is correct width for the bike but was wondering if the 9.5 mm is from a different model, mine being the k1 1972. Any chance you could measure your spares steved OR odd job just to confirm so I can safely fashion the correct spec. Will try and diy as I have with the rest of the bike but will leave the door open just in case guys.

[simonster]

Bryanj, I think you were bang on with your analysis. The bike had a missing chainguard within the cankcase and the break was just behind the oil seal. So refitted a chainguard from a donor case just need to sort the push rod!

[Trigger]

There are two different sizes of this rod and two part numbers. The larger diameter rod is for the K0 with 22850-292-020 and the K1 number is 11850-323-000. I am having the same problem.

[Bryanj]

Trigger there are two different part numbers but they are the same diameter as the seal is the same, there was a modification kit to improve neutral selection and gear location, if you have the star wheel on the end of the selector drum with a big and a small roller yours has been modified which included the lated pushrod

[Trigger]

Bryan, I thought the star wheel 24434-286-020 was upto 1018727 and 24439-323-000 was from 1018728. Have i got my information the wrong way round?

[Trigger]

Cheers Oddjob, that's a bit clearer. Yes, i have the 2 roller system in place. 

[simonster]

Mine definitely has the roller wheel mechanism in place.  Could an alternative to fashioning the domed end to fit the lifter plate be to have a ball bearing on this side?? Could this aid or cause any issues in the future? The rod may begin to flange around it but if it was heat treated on this side it could be an easier fix opposed to trial and error on getting the dome just right to match the lifter plate!