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Discussion Starter · #1 ·
Hey Folks,

I'm approaching completion on my 1965 CB160 project, having gotten past new piston installation, CAM Chain woes, wiring, valves and timing adjustment. Before I button everything back up, should a new clutch engage without oil running through it? I only ask since I was thinking I could crank the engine over with the kick starter to verify proper installation but everything is just slipping. I've read several threads on the discs, the order in which they go etc. and I think i've done everything according to the book (Clymers manual and others). There seem to be no published thickness specs on the metal discs (which seem to be true/not warped) and the friction plates are brand new. I even got upgraded springs and no dice. Hopefully this is just my ignorance showing and this is expected behavior. Can anyone confirm. Thanks in advance.

BTW, friction discs were soaked in oil and everything was "wet" upon install.

cb-clutch.jpg
 

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What do you mean by slipping? Like the engine won't turn over in neutral with the kickstarter? Does the kickstarter engage anything?

Have you tried without the cable attached?

Here's how I remember it working so that you can make sure the mechanical part is all there:

Kickstarter gear is meshed with a gear on the output shaft (sprocket), which is attached to the output shaft (and clutch, which has the inner barrel that fits onto the splines), which is then attached by the primary gears to the crankshaft. When you rotate the kicker the turning motion is transmitted through this path and turns the engine.
 

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Discussion Starter · #3 ·
Thanks for the reply, by slipping I mean that the kick starter only turns the inner clutch basket but the primary drive gear doesn't move, ie the clutch isn't engaging. I tried without the cable engaged as well. I can pop a screwdriver between a couple of the discs to create artificial tenstion and then it will engage and everything operates.
 

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That does seem like a disc/friction plate issue if you can get it to engage by making them closer together (and the fact that there's space to do so).
My first step would be to check cmsnl (https://www.cmsnl.com/honda-cb160-sport-general-export_model15852/partslist/E04.html#.XQgM7v5lC9t) to double check that you recognize every part that is supposed to be in it, and have the right number of discs/friction plates required (5 each I think)

If all is good I would be a little suspicious of new friction discs, if you have old ones measure them for a comparison and see what you find.
 

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Discussion Starter · #6 ·
Ok, I'm still lost. I'm fiddled with it for about an hour or two and everything is behaving the same. I have 5 steel discs and 5 new friction discs. I've consulted the diagrams on CMSNL and the Clymers. I spoke to Sprint66 and checked the orientation of the pressure plate inner clutch basket and rotated both in all possible positions. I'm now removed the clutch basket, reinstalled it, and that seems to be firmly seated in the proper location also. I've gone to the left side and taken all tension off the clutch lever and cable and I believe the Clutch pushrod is as withdrawn as it will physically go. I unfortunately discarded the old clutch discs already, but I've gotta tell you i've never seen anything so bad. There was literally no cork/friction material left on the discs. This leads me to believe my steel discs may no longer be in spec and that's why there is so much play. I've read that is uncommon though so I'm stumped.
 

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Does the pushrod come out easily on the left side of the engine? (might be bent and stuck in)....It SHOULD easily withdraw with your fingers....

I vaguely remember that some early models used a different (shorter?) lifter mechanism...... IS you serial number below B160-1045780 ?
 

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Discussion Starter · #8 ·
Thanks 66Sprint, i did do precisely what you mentioned here. The pressure plate, at least the one that came out of the bike, is uniform and seats properly in every position. The circlip installs fine and everything looks as it should. I sent a message to the ebay seller "valtermotousa" to ask him about the clutch discs. After revisiting the site it looks like these may not work. I don't think any Honda CB160s had a bend in the bottom steel clutch disk. From the ebay description "The original honda CB160/175 clutch consists of 5 lined plates with a lining width of 5/16", 4 plain steel plates, and one plain plate with a bend to hold the assembly away from the back of the clutch basket, and these Italian made clutch plates are a direct replacement."
 

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Discussion Starter · #10 ·
Thanks again, but the pushrod is true. It slides in and out easily. I measured the new friction discs and they are just shy of 3 mm. Doing some searches suggests that Vesrah/Barnett aftermarket clutch disks are 3.5mm....well 5 x .5 mm equals way to fu*!ing much space for the clutch to work. I'll keep everyone posted on the ebay response.
 

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Serial number question in post 7.......AND.....

Perhaps the spacing cure IS to substitute the later "B" plate (22321-302-000) for the innermost flat steel 160 plate....
How much thicker would the entire "clutch-pack" have to be to engage?
 

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Discussion Starter · #12 ·
Engine Serial is B160E-1013999
Frame is B160-1014047

Thanks for the suggestion on fixing the problem. I think I'll just order the correct discs and that should fix this issue that should have never occurred. If nothing else it was a good learning experience since i've done the job like 8 times now.
 

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You WILL have to order the early parts or you'll have the same problem....OR replace the one steel with a "B" steel and possibly run what you have (But I'm not 100% on this)
 

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Discussion Starter · #14 ·
Well I've ordered new friction discs, I think i'm significantly off. CMSNL and other sites do not show a different bottom disc. The ebay seller attached specs from a 175 that did have the different bottom disc but i can't find any evidence it ever existed on a 160. See attached image for the ebay response. The seller seems reputable and a specialist with these bikes but I'm not buying anything else from them. ebay-reply.jpg
 

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I don't think they are identical, although they DO share some parts....There were also differences between the "early" and later version 160's, and THAT is what I'm suggesting......
There is (so far) no proof that the clutch assembly is original to the engine/bike or that later 160 or even early 175 sloper parts were not installed as "updated" replacements at some time in the past....

Here is a Honda fiche page to show what I'm referring to..... It shows both the newer clutch discs and the upgraded oil pump assembly.... Please refer to part #17

late 160 clutch oilpump 001.jpg
Part #14 (the clutch center) WAS interchangeable on both early (below SN 1091953) and late models (after SN 1091953)...
(22120-216-000) Vs (22120-216-010), and while I'm reasonably sure either complete plate stack would work, the problem might be due to the intermixing of steels from the early version and frictions from the later version (or vice-versa) .......
 

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I was definitely not referring to you 66sprint, but to the vendor and other people (such as the PO of my bike) that don't even know there are early and late parts and don't understand why stuff they ordered/provide doesn't fit. The early 160s seem to share fewer parts with the 175s, the later ones definitely shared more.
 

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Discussion Starter · #18 ·
Well I'm happy to report back that the proper clutch frictions discs sorted everything out. The legit discs are 3.4 mm and fill the basket up properly vs the 2.9ish mm discs. No more slippage. thanks for chiming in on my issues guys, i greatly appreciate the collective experience and knowledge you've provided. I might be firing her up this evening. Cheers
 
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