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450's had a known tranny problem, most common symptom is what you describe. It happened on one of my old K2's, in fact.
There was a fixit "kit" from Honda in 1971 or so, consisting of a couple of countershaft gears and a shift fork.
It usually happened on CBK4 and older, but has been reported up to K6.
Engine must be pulled out, and cases split to affect repairs.

Your other problems sound like the carbs are not synched - read the "sticky" post on 450 carbs, it will probably cure it.
 

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The tranny problem will just get worse, you need to baby it till you get it fixed, or you'll end up with no second gear at all.....meantime, look for a good used tranny on EBay or something.
Brutal experience speaking here, I did this fix many times back in The Day. It was much more common on the models with chain oilers.....

Can't help with your "lift" question - you don't really need one to do this, but they are nice. 450's are probably the easiest engines to pull of all the old Twins, by the way.

I see by your zip that you're in Canton, Ohio, so I can't do much for you in the hands-on context unless you're willing to drag the engine/bike over here........

In the meantime, get your carbs set up and it will at least run better for you.
 

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bill,
do you think there are some of those kits still available? i hate to say it but my k4 sounds like it has the same problem. occassionaly i get a real loud clap sound switching gears, usually at higher rpm's if i remember correctly. does that sound like another symptom?

relatedly i'd really like to know what a top to bottom clutch adjustment entails. when you have time maybe could you elaborate on where to begin?
-seth
 

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uhohferris said:
bill,
do you think there are some of those kits still available? i hate to say it but my k4 sounds like it has the same problem. occassionaly i get a real loud clap sound switching gears, usually at higher rpm's if i remember correctly. does that sound like another symptom?

relatedly i'd really like to know what a top to bottom clutch adjustment entails. when you have time maybe could you elaborate on where to begin?
-seth

No, the "kit" was just the couple of parts from Honda. I don't think any of the parts are still available.
Not sure if I understand exactly the noise you're hearing.
The know tranny bug was pretty much specific to 2'nd and 3'rd gears........

To adjust your clutch, first screw in the adjuster on the handlebar all the way.
Then loosen the clutch adjuster bolt on the left side cover.
Pull in the clutch lever all the way and maintain slight pressure on it - you'll notice the slotted adjuster turn counter-clockwise when you do this.
Then, using a large screwdriver and still holding in the clutch lever lightly, turn that adjuster clockwise until there's about 1/4" or so of "slop" left in the clutch lever (more or less to your taste). You'll feel the adjustment pull the clutch lever back out when you do it.
Lock down the adjuster bolt and you're done.
If there's any weirdness, you may have to fool with the other cable adjuster near the engine first (other end of the cable from the handlebar).

Hope that expains it - takes longer to write it than it does to do it........
 

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I have the 2nd gear problem too. It is fine downshifting but will leap out on the upshift. I just last evening located a tranny from a 6000 mile bike so will switch out the tranny soon. I would really like to see the service bulletin pertaining to this if one still exists. Presently I nurse it from 1st to 3rd using all my Jedi skills. There aren't many old hondas with a gearbox that doesn't have some sort of idiosyncracy.
G
 

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twinz said:
I have the 2nd gear problem too. It is fine downshifting but will leap out on the upshift. I just last evening located a tranny from a 6000 mile bike so will switch out the tranny soon. I would really like to see the service bulletin pertaining to this if one still exists. Presently I nurse it from 1st to 3rd using all my Jedi skills. There aren't many old hondas with a gearbox that doesn't have some sort of idiosyncracy.
G
Sorry, I have no Servcie Bulletin on this, just my memory.
It was actually just an authorization from Honda to replace the afflicted parts, and then only on bikes that actually displayed the problem.
Most 450's, of course, never suffered from the problem. I had a pair of K2's, one had it, one didn't.

For the most part, all the old twin trannies were pretty durable, and all are pretty much built the same, differing only in the size of the components.......
 

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I had this issue with my CB500T. Having never been inside the bottom end of an old motorcycle tranny, I had no issue with splitting the cases and getting to the gears. It's not as hard as it sounds. I ended up replacing the shift fork and two gears affected with parts I found on ebay and forums. My bike now shifts great and holds 2nd like normal. The hardest part will be locating the parts you need, good luck.
 

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thats seriously encouraging souperman. if it were cold and bitter out i would have my lowercase split in my kitchen tomorrow.
 

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Not sure if it's the same transmission design but I had an S65 that jumped out of second gear (yeah I'm that old) and it seemed the three dogs that locked the gears together were bad about rounding off. I took them to a machine shop and they reground them back to a straight edge. I reinstalled them and never had another problem and I was 14 and ran the livin' S%#@t out of it.
Moral is if nothing is actually broken it can probably be repaired but no matter what it will need to be torn down.
 

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polymer said:
Not sure if it's the same transmission design but I had an S65 that jumped out of second gear (yeah I'm that old) and it seemed the three dogs that locked the gears together were bad about rounding off. I took them to a machine shop and they reground them back to a straight edge. I reinstalled them and never had another problem and I was 14 and ran the livin' S%#@t out of it.
Moral is if nothing is actually broken it can probably be repaired but no matter what it will need to be torn down.
Similar design, same problem though.
Also, the holes in the opposing gear would also get bunged up.
You can find a good used tranny for wht you'd pay a machine shop, at least in this case.
450 trannies are fairly common........
 

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Hey Bill,
If one was to rebuild a tranny to resolve the slipping 2nd gear problem or in general just 30+ years of wear on the whole tranny what would your parts list of items to purchase be?

Dave
Cb450 K7
 

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nerd01 said:
Hey Bill,
If one was to rebuild a tranny to resolve the slipping 2nd gear problem or in general just 30+ years of wear on the whole tranny what would your parts list of items to purchase be?

Dave
Cb450 K7
At least 2'nd and high gears on the countershaft, to take care of the jumping out of second gear problem.
Then possibly the shift fork on that side, depending on how it looked.

I think I'd also take a hard look at those spring-loaded detent rollers on the ned of the shift drum - they can cause this sort of thing, too.

If it was a K4/K3 with the bogus chain oiler, I'd look for a whole different countershaft.
Like I said, I found an entire K6 tranny on EBay for $9 - you just gave to be patient and watch things there.
If you can find a used tranny, grab it, never hurts to have spare parts........

Like this -
http://cgi.ebay.com/ebaymotors/Hond...7707047QQptZMotorcyclesQ5fPartsQ5fAccessories
 

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Discussion Starter #17
I have the engine out and have been taking stuff off. I'm stuck at how to get the alternator out. It's got a nut on it and if I turn it just turns the whole thing. How do you keep the alternator in one spot but turn the nut on the front of it?
 

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kdan311 said:
I have the engine out and have been taking stuff off. I'm stuck at how to get the alternator out. It's got a nut on it and if I turn it just turns the whole thing. How do you keep the alternator in one spot but turn the nut on the front of it?
Stick a penny between the crankshaft gear and the clutch housing gear (behind the oil pump).
You'll ruin your penny, but it will keep the engine locked in place.....
 
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