Topic: 1982 Honda CB900 10 Speed????

[dummkauf]

Ok, I am going to look at an 82 cb900 later this evening, and the guy I'm getting it from said he bought it last year and drove it for the season, however when he finally garaged it in November it was starting running around 7,000 RPM at idle, he thinks it's just a carb problem in which case a carb rebuild wouldn't be the end of the world.  The other curious thing is that he said it was a 10 speed.  He didn't realize it until he got it home and his neighbor, who apparently knows more about bikes than him, took it out for a spin.  Is this a stock transmission or is this some after market job someone put in?

[bill440cars]

Ok, I am going to look at an 82 cb900 later this evening, and the guy I'm getting it from said he bought it last year and drove it for the season, however when he finally garaged it in November it was starting running around 7,000 RPM at idle, he thinks it's just a carb problem in which case a carb rebuild wouldn't be the end of the world.  The other curious thing is that he said it was a 10 speed.  He didn't realize it until he got it home and his neighbor, who apparently knows more about bikes than him, took it out for a spin.  Is this a stock transmission or is this some after market job someone put in?

          The 10sp trans is a factory item and, If I'm right, came on the CB900C (for Classic).

[upperlake04]

 I searched for info on that model just a few days ago. From here

   "There certainly was some justification for the two-speed feature of the drive. Gold Wing owners never have been able to agree on the overall gearing their bikes should have: some want the ratio "tall," for low-stress cruising; others, habituated to hauling big loads and pushing bulky fairings, prefer the shorter gearing that lets them pull steep grades without downshifting. The CB900's Select Range feature provides two overall ratios. There's a 5.26:1 ratio (in fifth gear) for mountain or urban conditions, and a 4.50:1 ratio for economical cruising.

You can get economy, both in fuel mileage and engine life, by using the Select Range's high gear for cruising. In fifth/low the CB900's engine spins 4378 rpm at 60 mph; in fifth/high it turns only 3745 rpm, and feels like it's idling. There's a dramatic difference in fuel economy, too, which hints that the power engines need merely to overcome their own friction is significant. We rode the CB900 on a long loop around this area's freeways, first in fifth/low and then in fifth/high. Low-range riding returned 41.8 mpg; in high the mileage rose to 48.6 mpg. Using low-range for a period of maximum-effort performance and handling testing brought the CB900's mileage down to 28.5 mpg, and the overall average for the entire test was 37.2 mpg. That fuel consumption rate would give the Honda 164 miles before its 4.4-gallon tank empties, but running at a steady 60 mph would stretch the range to 184 miles if you keep it in granny, or 214 miles if you use the overdrive.

[dummkauf]

Good to know!  and thanks for the quick replies!!

I may be bringing it home tonight but that's yet to be decided, still need to take it for a test drive and make sure everything besides the carbs are in as good of shape as this guy's claiming.

[Soos]

I missed out on a CB900 here lately with a period honda dealer fitted fairing and bags.
I like the 10 speed gearbox though.
Cruising gears, and canyon gears is what I was thinking...
Good luck! good bikes from what I have read and heard from owners.




l8r

[dummkauf]

Ok, went over for a look and a test drive, and the bike starts right up, and it was idling just fine, and the guy selling it said he was even surprised it wasn't idling higher.  I revved up the motor several times until the motor got warm and it was still idling correctly.  I took it for a test drive and I got down the street to the first stop sign and stopped, as soon as I pulled the clutch in to stop the engine was revving up to about 4,800 RPM and staying there, as soon as I put it back into gear the RPM's were where they should be, and again pulling the clutch put the RPM's back up to about 4,800.  The sellers theory is that it is just gummed up carbs, and I'm inclined to agree with him, but I'm posting this to the knowledgable folks on this forum to see if it could possibly be something more serious than gummy carbs.   I can handle a carb rebuild, but I'm not buying this bike with the intention of rebuilding the entire motor.  And the RPM's did stay high after I parked it, shut it off, and restrarted it(started right up) and it was revving high again.

[upperlake04]

 I'm no expert, but that doesn't sound like a deal buster problem. Something is binding in the carbs, linkages, throttle or throttle cable.
 How does it look otherwise?
 

[dummkauf]

I'm not thinking it is either.  I offered him $900 for it and he accepted, and unless someone can think of a reason why the idle issue would be more than a carb rebuild I'm going to pick it up tomorrow afternoon.....and no I haven't paid him yet.

Here's the bike:




The wind jammer will be coming off and possibly the trunk too.  I wouldn't mind leaving the trunk but it seems too flimsy to actually hold someone leaning against it, so unless I can figure out a way to brace it better it's going.  Plus the trunk has the headlight and blinkers in it so I don't have to buy those parts when I pull the wind jammer off.  It also comes with the clymer's manual and the original owners manual.  The only thing I could find broken was the side cover panel on the right side comes off easily because one of the pegs the hooks into the bike is broken off, but I wouldn't consider that a deal breaker either.  It's got 48,000 on the odometer

[upperlake04]

For $900 which is $1160.Cdn dollars,  I would have bought it too.

[dummkauf]

That's 1$ per CC   

That and this seems like too good of a deal to pass up, and it is exactly what I was looking for....a cruiser for around $1,000 with a comfortable enough seat for my girlfriend to be happy with, now I'm just going to need to get used to the whole 2 shifter piece, and 10 gears.

[cb650]

http://www.cb750c.com/index.php       

[GroovieGhoulie]

So it's a 5-speed gearbox with a hi and lo-range, making it a 10-speed?

Similar, I guess, to the CT-90 with the eight-speed hi-lo range gearbox?

[333]

Yes, it's a dual range gear box.  City gears and highway gears.  But commonly referred to as a 10 speed.

My question is are you getting all the stuff to be able to take the Windjammer off?  Headlight bucket and hardware, anything that might have come off the back end...

[dummkauf]

Yes, it's a dual range gear box.  City gears and highway gears.  But commonly referred to as a 10 speed.

My question is are you getting all the stuff to be able to take the Windjammer off?  Headlight bucket and hardware, anything that might have come off the back end...

Actually, the bike came with all that stuff    The kid I bought it from was originally going to take the wind jammer off himself but he never got around to it.  He was a college student that bought the bike a year ago, and then had to move to an apartment and his parents didn't want the bike in their garage anymore so he had to sell it.  He already had a headlight, headlight bucket, blinkers, and the necessary brackets to attach it all, which all came in the trunk.  The trunk also contained the Clymers manual, owner's manual, and a brand new, unused, still in the box, cover for the bike .  The original wiring for it all appears to be wound up and bagged behind the wind jammer so I should just have to re run those wires, though I haven't actually opened up that bag yet to see 

As far as pulling the trunk off, it appears to just be screwed onto the luggage rack on the back, and the original brake light and blinkers are still on the bike underneath the rack, so I should just have to pull the trunk and disconnect the wires.

[dummkauf]

http://www.cb750c.com/index.php       

Thanks for the link, I've been meaning to locate a forum for the CB900, but I just bought it yesterday and have gotten good advice on here about my cb750 and figured someone here would know a thing or 2 about the cb900's as well. 

[cb750fbomb]

That's a sweeeeet bike. Congrats on that find and good luck with it. 

[dummkauf]

That's a sweeeeet bike. Congrats on that find and good luck with it. 

Thanks, I don't really have any big plans for it yet other than getting rid of the windjammer & trunk, and I'll probably be rebuilding the carbs this weekend and change all the fluids & filters.  I think I'm going to give it a good year of riding this season to make sure everythings running fine on it before doing anything else to it.  If all is well next winter I'm thinking I might get the tank and side covers repainted and start pulling the shiny parts off for buffing and just clean it up. 

So far there is only one tiny little piece of rust I noticed on the gas tank where it curves around the forks which I will just sand off and spary with some matching paint for now, otherwise I can't find a spec of rust anywhere else on it.....granted I haven't really pulled it apart yet.

Either way, I'm very excited about this bike, if you couldn't tell , and so is my girlfriend since I finally have a bike with a passenger seat that she will sit on(she refuses to ride on the Buell)

[MCRider]

So it's a 5-speed gearbox with a hi and lo-range, making it a 10-speed?

Similar, I guess, to the CT-90 with the eight-speed hi-lo range gearbox?

Yes, just like the trusty CT-90, I had one, bored out with a Powroll 110cc (or was it 102cc? kit.

And just like the CT-90, you must be off the bike to throw the dual range lever.

Also, the idle problem might be a flummoxed spark advancer.

[dummkauf]

So it's a 5-speed gearbox with a hi and lo-range, making it a 10-speed?

Similar, I guess, to the CT-90 with the eight-speed hi-lo range gearbox?

Yes, just like the trusty CT-90, I had one, bored out with a Powroll 110cc (or was it 102cc? kit.

And just like the CT-90, you must be off the bike to throw the dual range lever.

Also, the idle problem might be a flummoxed spark advancer.

Good to know....I'm still crossing my fingers that it's just gummy carbs.  Although why would a bad spark advancer cause a high idle, but normal operation when it's in gear and running?

[MCRider]

So it's a 5-speed gearbox with a hi and lo-range, making it a 10-speed?

Similar, I guess, to the CT-90 with the eight-speed hi-lo range gearbox?

Yes, just like the trusty CT-90, I had one, bored out with a Powroll 110cc (or was it 102cc? kit.

And just like the CT-90, you must be off the bike to throw the dual range lever.

Also, the idle problem might be a flummoxed spark advancer.

Good to know....I'm still crossing my fingers that it's just gummy carbs.  Although why would a bad spark advancer cause a high idle, but normal operation when it's in gear and running?

Well, it may not fit the symptoms granted. But a few things can happen. If the springs are fatigued, and the rotating cam is dry, once it spins out to operating full advance position, it should run fine. Then you  let off the throttle, it won't return to idle position. So you remove the cam and lube it where it rotates. And check the spring coils, they should be uniform.

Just a WAG, but I've seen them do funny things. I don't know for a fact you have that type of advancer. So take me with a grain...

The carbs are constant velocity type (CV) IIRC, so the slides are not connected to the cable and aren't forced to a closed position like they are on older CBs. So if the advance sticks, the carbs will cooperate and keep the idle high.

[dummkauf]

So it's a 5-speed gearbox with a hi and lo-range, making it a 10-speed?

Similar, I guess, to the CT-90 with the eight-speed hi-lo range gearbox?

Yes, just like the trusty CT-90, I had one, bored out with a Powroll 110cc (or was it 102cc? kit.

And just like the CT-90, you must be off the bike to throw the dual range lever.

Also, the idle problem might be a flummoxed spark advancer.

Good to know....I'm still crossing my fingers that it's just gummy carbs.  Although why would a bad spark advancer cause a high idle, but normal operation when it's in gear and running?

Well, it may not fit the symptoms granted. But a few things can happen. If the springs are fatigued, and the rotating cam is dry, once it spins out to operating full advance position, it should run fine. Then you  let off the throttle, it won't return to idle position. So you remove the cam and lube it where it rotates. And check the spring coils, they should be uniform.

Just a WAG, but I've seen them do funny things. I don't know for a fact you have that type of advancer. So take me with a grain...

The carbs are constant velocity type (CV) IIRC, so the slides are not connected to the cable and aren't forced to a closed position like they are on older CBs. So if the advance sticks, the carbs will cooperate and keep the idle high.

Good to know, I'll definatley give the timing advancer a look and see if there's any wear on the springs, I'm not familiar with the timing advancer but I'm assuming the cam you are referring to is a piece of that which means I only need to pop the cover off the side to get to it?  If that's the case I think I'll check that first since that's probably much easier to get to and check than pulling the carbs off the bike.

[MCRider]

yes, if its like our 70's CB with a point plate and the advancer below that, the advancer has a movable cam, the heel of each breaker point rides on it,  which advances upon acceleration to advance the spark timing.  It has springs which pull it back to retarded/idle position as the RPMs drop. If its not moving freely, odd things can happen.  It should turn and snap back.  Besides fatigued springs, I've seen the cam either dry or actually rusted to the spindle it moves on. Yours isn't rusted solid, but it may be dry and not moving freely.

With the point cover off, then the point plate off, you can wiggle the cam off the advancer easily. It should turn and snap back. Clean it, couple spots of white grease, waterproof grease. and slide it back on. A little maintenance that's good to do regardless.

All behind the points cover.

Its probably the carbs. 

[bender01]

My neighbor had one when i was a kid. Brown. There was a blue one in town too. Beautiful blue. Good buy.

[dummkauf]

I'm going to do the carbs regardless, but knowing about the points sounds like something to check regardless and it's been added to the to-do list to get the bike ready for this season.


Though now I have just discovered another problem....2 car garage with 2 cars, 2 functional bikes, and 1 bike in multiple pieces = my car no longer fits.  The girlfriends car naturally gets a spot inside no matter what but now I've gotta figure out how to relocate a lot of the boxes to get mine in.  I think my next project is to get some lumber and build a shelf about 4 feet from the ceiling all the way across the back wall to get a lot of the stuff up off the wall.  Gotta love how one thing always leads to another. 

[MCRider]

I'm going to do the carbs regardless, but knowing about the points sounds like something to check regardless and it's been added to the to-do list to get the bike ready for this season.


Though now I have just discovered another problem....2 car garage with 2 cars, 2 functional bikes, and 1 bike in multiple pieces = my car no longer fits.  The girlfriends car naturally gets a spot inside no matter what but now I've gotta figure out how to relocate a lot of the boxes to get mine in.  I think my next project is to get some lumber and build a shelf about 4 feet from the ceiling all the way across the back wall to get a lot of the stuff up off the wall.  Gotta love how one thing always leads to another. 

In my gargage, the square footage is limited, so the cubic footage is used. Lots of wasted space overhead. Besides a plethora of the wire type adjustable shelves from LOWES high on the walls, I have one of those units that hangs from the ceiling for storage. It has a 4' x 4' platform hanging about 20" from the ceiling.