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Old 09-17-2012, 11:47 AM   #31
rebelpacket OP
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Quote:
Originally Posted by disston View Post
From my understanding of gears, these are Hyphoid gears I think. The issues are not about the bearing load or preload. The issues are about how the teeth of the gears mesh and their contact pattern. It is a deep subject in general and then beings as we are trying to deal with the German machine it is so much more complicated.
The consequences of an improper set up are a noisy rear end and/or broken teeth in the final drive.
I'd love to actually understand this issue more. Anybody?
Actually, as I understand it, the contact patch on the gears is controlled by the shims between the pinon bearing and shaft. The bronze spacer between the needle bearing races is used to adjust backlash. The shim on the FD cover is exclusively for the distance from the crown wheel and the cover. The manual states:

Quote:
The required play is obtained after fitting the gasket, the crown wheel must not be under pressure
So it would seem the size of the gasket would effect the math for the proper "play" some..

I've never "blued the gears" as they say; never had a reason to. I have a basic idea of the contact pattern, what to look for , and how the contact patch is adjusted. I'm sure there is a formula out there to calculate shim size based on where the contact area is on the gear face, but I don't know it.

Quote:
Originally Posted by ontic View Post
the housing for the cam gear can also wear, alowing play in the cam gear, which then wears a new cam gear and throttle tube quicker. Might or might not be the case for you.
My R90 bits were all so chewed up I replaced all three.
Good call, I didn't think to check that. Mine looks pretty worn as well, so I ordered a new one. Chunky imprecise throttle is a real pet peeve of mine when riding.
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Old 09-19-2012, 09:03 AM   #32
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A quick update on the rather slow, but steady progress.



Its always fun making tools out of tools. I have a set of "crap" cutting bits that I use for projects like this. Doesn't need to be pretty or beautiful, just needs to work. This worked really well.



After pulling the swingarm off, I was "rewarded" with more rust sludge oozing out. I feel I made the right call taking it off to clean it out. The gritty sludge can't be good for bearings.



I had better access to the clutch release mechanism so I pulled that out. The seal on the trust piston was hosed, as well as the dust cover. More goodies on the way from Hucky.



The back of the transmission looked alright. A little wet where oil was getting past the busted seal on the trust piston, but nothing from the output.



Peering into the intake ports, I found something a little puzzling. I've never looked into the port of an airhead, so I don't know what normal is. It looks to me like someone stuck a dremel in and tried to do a quick and dirty porting job. Maybe they all look like this? There are scrapes on the valve guide, which doesn't seem very "german" to me. Its a bad picture, maybe the collective can tell me what happened here?



The carbs we're as dirty as I expected. Probably going to need a few new jets if everything has this rusty sludge in it. I do find the floats in these carbs particularly cool. Never opened up a BING like this, and the float setup seems pretty genius to me. I'll probably start cursing it later.



And here is where everything sits. I wasn't planning on removing the transmission. However, at this juncture, with everything off, I feel like it'd be irresponsible not to pull it off and give the input splines a little grease. I've read and looked for a "felt washer" that sits at the end of it. I've never pulled the transmission off a BMW, so I'm not sure what to expect/look out for. Should I pull the clutch pushrod out? Is there a chance I can bend/break that on removal? So many questions... so many google searches.



Things are slowly getting there though, moving from back to front. The oil pan and new gasket are on. The final drive is back together, and the swingarm is spending a time-out in a kerosene bath. I (foolishly) still think a 30th birthday ride in October is plausable.
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Old 09-19-2012, 09:18 AM   #33
blaine.hale
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That's not a stock r75 /5 bing float set up that i've ever seen.
I mean, I've seen that before, just not on a /5.
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Old 09-19-2012, 09:23 AM   #34
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That's one of those Bing "alcohol proof" float kits
They have no overflow, and are a pain in the butt in a lot of ways.
They were originally meant for airplane engines, (or so the urban legend goes)
Ditch those and buy the right stuff.
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Old 09-19-2012, 09:33 AM   #35
rebelpacket OP
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Quote:
Originally Posted by wirewrkr View Post
That's one of those Bing "alcohol proof" float kits
They have no overflow, and are a pain in the butt in a lot of ways.
They were originally meant for airplane engines, (or so the urban legend goes)
Ditch those and buy the right stuff.
Ahhhhhhh. Thank you very much for that. I was starting to think I was crazy.

So, looking at what a kit contains, I'll need a new floats and float bowls? I can't find anywhere that describes the content of the kit, so I'm unsure what is compatible.

The lack of overflow is really dumb. The oil in the smelled very strongly of gas, so I'm guessing these have been overflowing into the cylinders for some time now.
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Old 09-19-2012, 09:43 AM   #36
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Quote:
Originally Posted by wirewrkr View Post
That's one of those Bing "alcohol proof" float kits
They have no overflow, and are a pain in the butt in a lot of ways.
They were originally meant for airplane engines, (or so the urban legend goes)
Ditch those and buy the right stuff.
By right stuff, I assume you just mean the stock looking ones that aren't cork, but a white plasticky kind of feel?

I run those in my bikes and they've been perfect for a couple years.
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Old 09-19-2012, 09:44 AM   #37
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A lot of riders prefer the regular float system to the Bing Alcohol Proof system. I wrote to Bing about 6 months ago about maybe another solution for the alcohol problem. Their answer to me was something along the line of they do not have a problem with the current alcohol system.

Those are the Bing Alcohol Proof system floats and bowls. If you go back to stock those should sell easily. They are much more expensive than the stock system.

The over flow is part of the stock bowl so you get it back with a stock bowl. I think the whole system is only the bowl and the floats. Maybe some tiny clip/hardware things?
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Old 09-19-2012, 09:44 AM   #38
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Quote:
Originally Posted by rebelpacket View Post
Ahhhhhhh. Thank you very much for that. I was starting to think I was crazy.

So, looking at what a kit contains, I'll need a new floats and float bowls? I can't find anywhere that describes the content of the kit, so I'm unsure what is compatible.

The lack of overflow is really dumb. The oil in the smelled very strongly of gas, so I'm guessing these have been overflowing into the cylinders for some time now.
You just need the floats ($46 a pair) the needle to support them ($2 a pair) and the float needle should already be there, I don't imagine that changing.

*edit: looks like the supporting needle for the float mechanism is already there too. Soooo just the floats are needed. Yay
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Old 09-19-2012, 10:00 AM   #39
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Scooter ok here?

I have a 2006 Morphus Scooter with 4000 miles on it. Does anyone know anything about these mechines?
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Old 09-19-2012, 10:00 AM   #40
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Quote:
Originally Posted by blaine.hale View Post
You just need the floats ($46 a pair) the needle to support them ($2 a pair) and the float needle should already be there, I don't imagine that changing.

*edit: looks like the supporting needle for the float mechanism is already there too. Soooo just the floats are needed. Yay
need the bowls too.
the needles on /5 /6 carbs are the solid metal ones, not rubber tipped and NO clips.
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Old 09-19-2012, 10:11 AM   #41
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Thanks a million for your help folks. I just went and took it apart to figure out what I'll need.

Any idea what these kits are worth? I don't want anything to do with them, but I'm sure there is someone out there that is looking for a set to pop up for sale...

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Old 09-19-2012, 10:15 AM   #42
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And the bowls, the bowls...oh, Wirewrkr already got it.

Smoothing the flow path of the intake runner is probably still popular. We did this a lot years ago. But the Dremil was not common then, they were around just not as common. I remember doing this with finger pressure and a piece of ruff sandpaper. The direction of the scratches look like Dremil Tool. The idea is to just smooth a little and not take too much material off.
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Old 09-19-2012, 11:19 AM   #43
rebelpacket OP
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Quote:
Originally Posted by disston View Post
Smoothing the flow path of the intake runner is probably still popular. We did this a lot years ago. But the Dremil was not common then, they were around just not as common. I remember doing this with finger pressure and a piece of ruff sandpaper. The direction of the scratches look like Dremil Tool. The idea is to just smooth a little and not take too much material off.
Thanks for your insight Disston; It sounds like what happened. I'm finding all sorts of little things like this all over the bike.

I'm slightly afraid to remove the transmission now...
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Old 09-19-2012, 11:40 AM   #44
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There is really no problem removing the trans now that you have all that other stuff off anyway. It looks like the bike was exposed to water during an inactive period? I've never seen that much rust in the swing arm. If any of the three parts in the drive train were to have this problem tho I'd rather have that than water in the trans or the final drive. There's lots of meat in the drive shaft splines and I think the universal is pretty water proof so it should all clean up. The universal is lubed and sealed it is not lubed by the gear oil in the swing arm.

With the trans out you will be able to see if the rear engine seal/oil pump cover is leaking or the input seal on the trans. Pay attention before cleaning, is there oil behind the clutch or is it coming from in front of the clutch. But you don't suspect an oil leak at this time? It may look different when the trans is out of the way.

All this water I'd want to clean and lube the splines.

You have not pulled all the parts yet to the throw out mechanism. There is one more thrust piece in front of the bearing. The rod actually comes out easier from the front. There is a felt seal on the rod that's a pain to replace I often don't replace it because of this if the old one looks serviceable.

Need new rubber pieces nobodies surprised there. The real question is do you feel up to removing the clutch for checking and then the flywheel to look at the rear seal. After you have the trans out you should be able to make a better informed decision. There are several extra tools to get into the clutch and install a rear seal but we'll cover all that if needed later.
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Old 09-19-2012, 11:46 AM   #45
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Actually the little bit of flow work on the the intake runners indicate to me somebody did take care of this machine. Maybe it's had valve work, guides maybe?
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