Honda Twins banner
1 - 20 of 36 Posts

·
Registered
Joined
·
204 Posts
Discussion Starter · #1 ·
HI just watched a video on youtube on clutch repair Honda cb 450 . in the video you can clearly
see pressure plate moving in and out as he pulls clutch lever .. My bike does not do this . I have no movement at all in pressure plate just a small separation of about 3or 4mm in the first two plates.. The reason I am still looking at clutch is that when I took my bike for a ride after I did clutch adjustment (with side cover off) I noticed it would go up into second if I slipped clutch( with the revs up) or double shuffled clutch. Should I be able to see pressure plate move ?.thanks
 

·
Registered
Joined
·
13,085 Posts
I haven't actually ever tried to see movement in the pressure plate with the clutch cover off, so I can't speak to the amount of movement. I would like to see the video you mentioned so if you could post the link here that would be great. As for the detent star being repaired by brazing and then re-finishing - I can see how that would work fine, except that brass isn't as hard as steel and it would wear away more quickly
 

·
Registered
Joined
·
204 Posts
Discussion Starter · #3 ·
Iam convinced my my clutch plates /friction plates are not opening up enough even with clutch adjusted correctly I have broken then apart before installing
like I said I have very minimal movement when I pull lever
 

·
Registered
Joined
·
2,581 Posts
If you see separation in the plates, the pressure plate must be moving, since it is what presses the plates together. What you must have seen was the outer plates sticking a little to the pressure plate and moving with it.
By 'slipped clutch', I assume you mean partially engaged. This would put some drag on the transmission input shaft, and make the mating faces of the gears slide against each other, until the gaps in the teeth line up. I can't help wonder if the input shaft is slowing too quickly, impeding the shift
 

·
Registered
Joined
·
13,085 Posts
From what I can see, the pressure plate only moves about half the thickness of the outer edge of the pressure plate itself - which seems like only about 3 to 4mm, because 1/4" is roughly 6mm and it doesn't look to be moving that far in his video. If you've done the clutch/cable adjustment correctly and all the required parts are in place, I can't imagine what would keep the clutch from disengaging enough to cause shifting issues.
 

·
Registered
Joined
·
204 Posts
Discussion Starter · #6 ·
Ok thanks Tom all the required parts are in place(Honda shop manual) Rick, input shaft slowing ? that sound like splitting the cases . really getting way past my pay grade.. I will check out star detent and take it from there . the neutral stopper and pizza cutter are good. Looks like I will have to drill out philllip head screws in bearing plate. thanks and I will report back
 

·
Registered
Joined
·
2,581 Posts
There has to be some relative motion between the input and output shaft, so the teeth on the gear faces can 'find' each other. This is why you can't shift when the bike is not moving with the engine off, or sometimes, if you hold the clutch disengaged for too long before attempting 1st. If, for example, the 2nd gear that should spin free when not in 2nd is binding to the shaft, it will cause the input and output shafts to spin at the same rate and, if the facing teeth happen to be aligned tooth-to-tooth, it will not shift. You could also have a bent shift fork, which doesn't move the 3rd/2nd gear far enough to engage those teeth in the 2nd gear position. Only way to tell if the forks are bent is to take the engine bottom case off.

Describe how it doesn't go into 2nd. Is it like a false neutral, where the lever moves as it should, but the gear just doesn't pick up and maybe clicks back out, or does it feel like the lever is blocked from going far enough? When it should be in 2nd, can you shift again and go into 3rd?
 

·
Registered
Joined
·
204 Posts
Discussion Starter · #8 ·
Hi Rick and Tom .Can I first ask how to get out shift drum ?..have removed bearing plate but it seems to be held in by ball bearing. About the way the bikes shifts ... here is my best description. Firstly it has a mind of its own and sometimes it engages second , sometimes not.(usually not).. once in 2nd the rest of top gears are fine ... back to first no worries . If I hold upward pressure on gear change pedal while riding it will stay in second ..once I let pressure off the neutral light comes on but sometimes no neutral light (so it has gone into 2nd)and I can continue to shift up .(I am at the mercy of the neutral light) I have learnt that if I change real fast with revs up it will usually work ok but it isn't a very comfortable way to ride. Would say it is more like your first scenario Rick, i.e false neutral. should I continue with getting out star detent .? the tips don't seem to have a lot of ware. thanks
 

·
Registered
Joined
·
204 Posts
Discussion Starter · #9 ·
I should add that earlier I replaced the gearshift spindle . the hook on the end broke off, probably from me being rough forcing it into 2nd .I don't now if it is of any significance but when i replaced I just let the end of the new one (hook) pop in to where ever it wanted to go because I had less Idea then than I do now , if that is possible
 

·
Registered
Joined
·
2,581 Posts
Sure sounds like a bent shift fork. The shift drum and the rest of the transmission are only accessible by taking the bottom case off. Do you have the factory service manual? Section 3.5 covers the transmission and shifting; it takes a bit of study, but really helps with figuring out shifting issues. I think your counter shaft top gear is not moving close enough to the 2nd gear to fully lock the facing teeth; if they even get partially engaged, the faces are tapered to pull them together, but the corners can wear, causing them to push back apart. A quick flip of the lever can sometimes move it fast enough to engage, which is likely what you are doing at higher rpm.

The engine will have to come out, and it's a real anchor. I've done it several times my self, but it's getting to be a real grunt as I get older. A strapping young lad makes all the difference, as does a platform at the same height to roll it onto. Once it is out of the frame, make a stand to hold it upside-down, and the case pops off fairly easily; both side covers off first, of course. One step at a time, and take photos, and you'll be done 'before you know it'. Before you start, assume you'll need, at least, the shift fork, and check to see if they are still available.
 

·
Registered
Joined
·
2,581 Posts
BTW, if you don't have that section of the manual, and do have an email service that will accept 7-8M files, I can email you just that section, so you can spend an evening on your computer at study. Just send a PM with your address.
 

·
Registered
Joined
·
13,085 Posts
...probably from me being rough forcing it into 2nd
Based on that phrase right there, I'd agree with Rick - if a shift fork wasn't very bent before, I'd suspect the hard activity on the shifter contributed to your issues. These engines aren't designed to use a lot of force on the shift lever, you have to use the clutch properly and lift and push the shifter, not kick, or damage will result no matter the age of the parts. I wasn't convinced it was clutch-related at all, honestly. While you're in the transmission, post pictures of all the gears and shift forks... when there is a bent fork, there can also be wear on the engagement dogs on the gears and if not replaced at the same time, will result in a repeat of the same problem later. BTW, the shift drum didn't come out because the forks go over it and have pins in them... again, go to cmsnl.com or partzilla.com, look up the bike by model number and look at the exploded view of the parts to get a better understanding of how it all fits together and it will be more clear why certain parts are arranged and disassembled they way they are
 

·
Registered
Joined
·
204 Posts
Discussion Starter · #13 ·
Hi Rick, thanks for all that information , I am going to give it a go . Just some background . Bought the bike with a stuck motor, tried to get it unstuck, no luck so I did take the motor out and found that the crankshaft was broken at the connecting rod. Managed to find another motor , which I put in . I had lots of help via email from 450roo. Hopefully there are parts in the old motor I can use.
Before I take the motor out I want to compare the 2 star detent roller . Have bearing plate off but I can not get the bearing out of case. Do I need a puller or some other tool.How does it come out? thanks for all you help
 

·
Registered
Joined
·
204 Posts
Discussion Starter · #14 ·
Sorry I get it now . Can not get to star detent roller without removing Botton case.. (a bit slow on the uptake) I understand now . I will pull motor , flip it upside down ..remove bottom case. hopefully find 1 of the 3 shift forks bent ... replace (hopefully the ones in the original motor are good) silicon back together put back in bike and finally ride off into the sunset like I planed to do last September when got the bike .Thanks Tom and Rick will post pictures when I get it apart . Also Rick it was my wife who helped me remove and old motor and put in second one . I haven't broken the news to her yet that it hast come out again . Kanga
 

·
Registered
Joined
·
3,537 Posts
Sorry to see you are going through all of these problems. It is quite common to discover the original problem that took the bike off the road back in the day. Sometimes they can be deep rooted so the previous owner never got around to fixing it. In the image below the selector star is part #8. It is held in by screw #43. The screw has been staked and will need to have the stake drilled out and then restaked when it is put back together. At this point I agree with the problem is in the transmission and maybe a bent shift fork. The primary function of the selector star is to give the shift level the positive feel and keep the shift drum in the proper rotational alignment. As you can see in the diagram the drum (it is actually about a 50 mm diameter rod of steel) has slots in it that move the shift forks back and forth as the shift drum is rotated by the shift linkage acting on the shift drum. There are pins (part #4) in the shift forks that are held in by clips (part #5). It is also possible one of the pins has dropped out and the second gear is not moving as programmed by the shift drum. I watched your video and I think your clutch is correctly functioning. There is only one thing left to do and that is pull the engine and go into the transmission. BTW- please wear shoes and a helmet when you ride.

Auto part Axle part Automotive engine part Transmission part Technical drawing
 

·
Registered
Joined
·
204 Posts
Discussion Starter · #16 ·
Ok Jim I always wear shoes and have started to wear a helmet. BTW JIM that is a Video I got off youtube that isn't actually me.I have the motor ready to lift out.will do that in the morning . Could you please elaborate on drilling out the screw and restaked .(I have no idea what that means ) what size drill bit etc.
 

·
Registered
Joined
·
204 Posts
Discussion Starter · #17 ·
Hi at this stage I am hoping to get motor out in the morning(its ready to come out just waiting for someone to give me a lift) I will remove bottom casing and all being well I will report back and hopefully the problem is obvious .Rick apparently we can not receive that size files . At close inspection I can see that the motor has been apart previously. Do you think this will make it harder to break apart ?.Also any advice on how to split the casings would be great , thanks
 

·
Registered
Joined
·
2,581 Posts
Staking a screw is using a punch and hammer to dent the edge of the screw head; the dent presses into the mating surface, and functions as a lock, so the screw can't back out. This was used before thread locking compounds were invented, and worked quite well on parts you didn't expect needed removal. Sometimes, you can overcome this lock with a hammer driver and a properly sized bit. But, if the staking is deep enough, you will have to drill out the dent. I would replace the drilled screw with new, and stake it in another place, or use a thread locking compound. Over here, these compounds are color coded, and red will never release, blue will need that hammer driver, and green or purple maybe a tap with the driver or strong hands - I would choose the blue, as with such a small screw, the red would need a torch to soften it.
 

·
Registered
Joined
·
2,581 Posts
Hi at this stage I am hoping to get motor out in the morning(its ready to come out just waiting for someone to give me a lift) I will remove bottom casing and all being well I will report back and hopefully the problem is obvious .Rick apparently we can not receive that size files . At close inspection I can see that the motor has been apart previously. Do you think this will make it harder to break apart ?.Also any advice on how to split the casings would be great , thanks
Well, you can see if the link for the service manual, above, is still active. It's a big file, so could take some time downloading. I was lucky enough to both download a copy (in pdf format) and find a paper copy on eBay.

See if this works for you: http://www.common-motor.com/manuals

How hard it is to take apart depends, entirely, on what might have been used to seal it. All the ones I've opened just took some carefully applied taps with a hard rubber mallet. Resist, if you can, trying to pry it up, for fear of scarring the mating surface. BTW, if you use silicone sealant to put it back together, be very stingy with it, or it can squeeze out and break off into the oil. You don't want that. If you can reach a Honda dealer, Hondabond is a better choice.
 

·
Registered
Joined
·
204 Posts
Discussion Starter · #20 ·
thanks Rick I am hoping the the shift drum can stay intact . I think I have a fair idea of what I have to do . got a friend coming over in 1hr . to lift it out . I am just hoping the problem is obvious . About to find out .Thanks for all your help
 
1 - 20 of 36 Posts
Top