The Vintage Bike Thread (pre-1980)

The Something Awful Forums > Discussion > Automotive Insanity > Cycle Asylum > The Vintage Bike Thread (pre-1980)

Rev. Dr. Moses P. Lester: Oct 3, 2000

my 1955 bmw R50.

as bought: (didn't run)

now:

currently undergoing a tranny rebuild because of one bearing with a broken outer race. dunno how that happened. everything else in the trans looked good for another 100k.

of all the bikes i've worked on so far, some 70s and 80s japs, moto-guzzi, ktm, this is the easiest and most enjoyable to fix. there are no unnecessary parts on it and almost everything is easy to get to.

# ¿ Oct 22, 2009 12:35

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# ¿ May 23, 2024 12:22

Rev. Dr. Moses P. Lester: Oct 3, 2000

rope kid posted:

My '73 BMW R60/5 teardown starts this weekend. I just picked up some damaged R75/5 cylinders for the engine rebuild. When it's back together, it should be a five-speed R80/5. Once it's finished, I'm hooking it up to a CJ sidecar.

i must have missed this in your thread... was the engine blown? or are you just upgrading to 750 for shits and sidecars?

RogueEngineer posted:

guhh I love old BMW's. Any of you go through the trouble of mounting and balancing your own tires? I'm debating giving it a try.

tubed tires are a hell of a lot easier. tubeless i just take to the shop.

# ¿ Oct 22, 2009 19:19

Rev. Dr. Moses P. Lester: Oct 3, 2000

egh, i'm surprised. i've used their tank sealer poo poo several times and was impressed.

that thing looks loving rad already, though.

# ¿ Feb 18, 2010 05:46

Rev. Dr. Moses P. Lester: Oct 3, 2000

old german bikes are tough on tools

well, lovely too small tools

ARYAN STEEL (in the transmission output flange, not the jap crap socket extension)

# ¿ Apr 8, 2010 21:11

Rev. Dr. Moses P. Lester: Oct 3, 2000

Blaster of Justice posted:

How the gently caress did you manage to do that?

which one? first one i was straightening a US handlebar from a bmw /2 using a lovely vise, i decided the thing to do was just to use a big pvc pipe to get more leverage on the vise tightening bolt. handlebar survived (still bent), vise didn't. second one was me tightening the output flange on a /6 bmw transmission, using a torque wrench and a 15/16 socket and a 3/8" short socket extension. made it to 130ft-lb or so before the socket extension got up and went home. got a new 1/2" deep socket and made it to 180ft-lb safely.

# ¿ Apr 10, 2010 11:09

Rev. Dr. Moses P. Lester: Oct 3, 2000

clicky noise follows rpm? doesn't go away above idle? rockers or cam chain, yeah. rockers and chain tension worth checking. if it can't be fixed that way, it could need a new tensioner or a new chain, but generally speaking those engines make a lot of clicky noises, especially if they're high miles, and it's not a problem. it's just the way they're built. it would have to be a really pronounced clicky noise to demand attention. they're not supposed to be quiet like a modern i4 car.

# ¿ Dec 2, 2010 20:57

Rev. Dr. Moses P. Lester: Oct 3, 2000

tensioner is in the cylinder block so replacing that means a top end teardown. thats a big job if you're new to working on engines. 8800 miles seems rather low for a 70s cb to me, those things are usually beaten on and parts replaced and etc. including odometer.

i'd get some feeler gauges of the right size and check the rocker clearance more carefully. it's not too hard and it's a good job to do for learning about engines. i'm gonna make up a rule of thumb and say if the clicking is difficult to hear above like 3k rpm, your engine is fine. unless you have straight pipes. so change the oil every now and then and it'll last forever.

fyi, there is another similar noise common to these engines, though louder and uneven and more like a clunk, which is heard mostly at idle. it is some slap (looseness) in the primary chain (chain between engine and transmission) and it is not fixable without a total rebuild, but is also ignorable unless it's really loud.

# ¿ Dec 3, 2010 04:15

Rev. Dr. Moses P. Lester: Oct 3, 2000

Carbonate posted:

carb cleaning/syncing

this will help the primary chain slap noise too

# ¿ Dec 3, 2010 20:48

Rev. Dr. Moses P. Lester: Oct 3, 2000

i dunno about dual sport tires but there's a guy on a moto-guzzi forum i know who seems like a pretty hardcore rider in that he rides year round, and he runs cheng shin trials tires the whole time. i thought that was insane and the knobs would just pop off or something but he swears it works great. and works in snow too.

but that is a guzzi owner so take it with a grain of salt.

# ¿ Dec 5, 2010 08:50

Rev. Dr. Moses P. Lester: Oct 3, 2000

Quite a number of people in here who are motorcycle mechanics despite having never ridden a bike. Cause why would that be necessary, right?

# ¿ Oct 12, 2011 00:54

Rev. Dr. Moses P. Lester: Oct 3, 2000

GnarlyCharlie4u posted:

Alright! My flip camera came in so I took a video of my goldwing doing it's crazy idle surge.

Please watch: it's only a minute long.
Any suggestions good or otherwise are welcome.

http://www.youtube.com/watch?v=d8nNX2IGa4E

I've never worked on a Wing's carbs, but we see problems like that on old japanese bikes all the time at our shop. It's almost always a small air leak (or leaks) on the intake. It could be relatively easy to fix, like replacing or siliconing the manifold boots, or it could be that the carbs are just worn to hell and every little moving part in them is too loose. Could also be just a lean condition because the idle mixture screws or the slide needles need adjusting. As was said before, your open pipes are likely playing a part in this too.

I'd check for air leaks at the boots between the carbs and engine (idle it and spray something flammable like carb cleaner around the boots, but not into the normal intake, and see if the idle speed goes up because it's sucking the aerosol in and burning it) and then start throwing bigger jets at it, adjusting mixture screws or raising the slide needles to richen things up. I see you've done some of this, but you may just need to do more. It is normal to need bigger jets (fuel jets not air jets) when running open pipes.

# ¿ Oct 22, 2011 02:25

Rev. Dr. Moses P. Lester: Oct 3, 2000

TyChan posted:

Is there a company that makes drum-to-disc brake conversions kits for vintage bikes or do you have scrounge around for later model brake parts from the same bike manufacturer and hope they can fit one way or another?

I'm just kind of curious.

Scrounge around. Or look for custom aftermarket stuff. There is no easy or cheap answer to that one.

# ¿ Nov 8, 2011 03:34

Rev. Dr. Moses P. Lester: Oct 3, 2000

Actually that head looks pretty nice to me, considering. What happened exactly?

# ¿ Dec 12, 2011 00:46

Rev. Dr. Moses P. Lester: Oct 3, 2000

Aren't the teflon things supposed to touch the cylinder walls? I thought that's why they were teflon.

# ¿ Jan 4, 2012 21:57

Rev. Dr. Moses P. Lester: Oct 3, 2000

Looks like awesome wiring too

# ¿ Jan 26, 2012 03:48

Rev. Dr. Moses P. Lester: Oct 3, 2000

I had a CB550 with wiring that lovely once, which makes sense on a loving CB550, but a '51 BSA? Who does that

# ¿ Jan 26, 2012 06:01

Rev. Dr. Moses P. Lester: Oct 3, 2000

The shape of the camshaft lobes which push on the valves and determine how quickly and far the valves open as the piston goes up and down

# ¿ Feb 12, 2012 01:23

Rev. Dr. Moses P. Lester: Oct 3, 2000

I've seen a lot of ugly crap in old gas tanks, poo poo you don't want in carbs. I've installed a lot of generic in-line filters on old bikes. I've never seen one with performance issues after it. This does not include bikes with fuel pumps.

# ¿ Mar 16, 2012 00:37

Rev. Dr. Moses P. Lester: Oct 3, 2000

Another point of clarification on electrics: if a battery has 12.6+V with no load, it does not prove that the battery is good. It is possible for a battery to have a "surface charge" where the voltage looks good when unloaded, but drops significantly when you're pulling current from it. You need a load tester, or a multimeter and a load like a starter motor in a bike, to fully confirm a battery is good.

# ¿ Mar 20, 2012 17:28

Rev. Dr. Moses P. Lester: Oct 3, 2000

I don't think that's necessarily cheating. If you've got an electrical gremlin like a damaged and rusted wire from age that takes 2 hours to track down on a 30 year old bike, it's not a leap to say that there will be other wires likely to go soon too. A new harness is a fair solution to that. Like new pistons, rings and a bore would be on an old engine.

# ¿ Mar 22, 2012 05:16

Rev. Dr. Moses P. Lester: Oct 3, 2000

Nerobro posted:

Four cylinder bikes are a LOT more plesant to ride. They're magic carpet ride-ish. Smooth. They sound amazing too. Nothing like the sound of a two valve four cylinder. (If you've ever heard a MG midget screaming around a race track, you know what I mean.)

Of all the things in the world that are wrong, Nerobro is the wrongest. I4 is the most boring engine configuration. Triples are better, parallel twins are better, v-twins are best. Old japanese four cylinder bikes are particularly bad. Most of them are unreasonably heavy, not very powerful, heavy throttles, other minor issues. They don't rev high enough to sound like a GP bike so I don't see how they sound can be that cool. The question of smoothness is really a red herring in my opinion. Anything that isn't a 1976 Harley or a 1976 Norton is plenty smooth enough to ride comfortably.

# ¿ Mar 26, 2012 06:06

Rev. Dr. Moses P. Lester: Oct 3, 2000

iwentdoodie posted:

It feels like it just wants nothing more than to be railed on, 6000RPM to redline feels like God himself is trying to punt you off the bike.

And you don't even have aftermarket pipes on it yet.

# ¿ Apr 12, 2012 02:46

Rev. Dr. Moses P. Lester: Oct 3, 2000

Yeah if they're old and rusty, I'd just replace all the cables. Don't mess with old crappy cables if you don't have to. Especially considering you have a cable driven drum front brake.

# ¿ Apr 17, 2012 04:05

Rev. Dr. Moses P. Lester: Oct 3, 2000

Sagebrush posted:

Out of curiosity, how many people is that now who have CL350s? I do, CloFan does (did), Dolphin does, and Front Wing Flexing seems to. Anyone else? Too bad we're not all in the same place...could form a gang of old Scramblers.

(or not, since in the words of an ex-con who was at my MSF, "if it's gang-related it increases your time served")

My shop has one. Or had one, until we messed it all up to turn it into a track bike. But it is still a cl350 frame, engine, forks and wheels. Here it is after its first race, a blown engine, a fire, and a dousing by a track worker with an extinguisher:

# ¿ Apr 17, 2012 06:03

Rev. Dr. Moses P. Lester: Oct 3, 2000

As a general rule of thumb, if any two pieces of metal are rubbing together anywhere, they need to be lubricated by something. This isn't always true, but almost always.

# ¿ Apr 25, 2012 06:16

Rev. Dr. Moses P. Lester: Oct 3, 2000

Sagebrush posted:

I don't know if there's a special kind of tool that you can use without a vacuum port,

This was originally designed for use on old VWs:
http://www.jcwhitney.com/carburetor-synchronizer/p2008076.jcwx?filterid=d50155y1973u0j6

I've used it on my old BMW and a the shop's CL350. Works pretty good. Just have to remove airboxes and hold it over the carb intake.

# ¿ Apr 27, 2012 18:19

Rev. Dr. Moses P. Lester: Oct 3, 2000

Sagebrush posted:

Or do you need two, so you can measure both at the same time to ensure that the airflow restriction is the same?

You can do it with two if you want to be fancy about it, but I just hold it over one intake and then hold it over the other and remember the numbers.

# ¿ Apr 28, 2012 02:47

Rev. Dr. Moses P. Lester: Oct 3, 2000

No, it's just a pain in the rear end.

# ¿ Apr 28, 2012 22:35

Rev. Dr. Moses P. Lester: Oct 3, 2000

As a PROFESSIONAL TRAINED vintage bike technician I hereby endorse Nerobro's advice and condemn Sir Cornelius's. That is all.

# ¿ Apr 29, 2012 18:46

Rev. Dr. Moses P. Lester: Oct 3, 2000

Maybe it's just because I don't RIDE AT THE LIMIT and PUSH THE ENVELOPE and do this https://www.youtube.com/watch?v=wtrmcza3ppE every day like Nerobro, but I've never had a problem with any tire, and I've had all kinds of different good, so-so, crappy, and super crappy brand tires. The only quality issues I've seen with any tires is with certain years of manufacture of Dunlops which dry and crack before they ought to. I buy whatever's cheapest.

# ¿ May 1, 2012 07:19

Rev. Dr. Moses P. Lester: Oct 3, 2000

Sagebrush posted:

And that's actually not that bad, at least it's still semi-fluid. When it gets real bad, it turns into something very much like actual varnish, and is as hard as actual varnish, and requires serious solvent and agitation (like an ultrasonic cleaner) to get it loose.

# ¿ May 2, 2012 03:00

Rev. Dr. Moses P. Lester: Oct 3, 2000

Sir Cornelius posted:

You shouldn't have posted this, mate. Now Nerobro will challenge you to a forum death-fight.

Nerobro will look straight through your sinful carburetor soul with those cold dead eyes and tell you that the pilot system matters a gigantic fuckload at WOT.

The real scary thing is that Nerobro might be almost half-right. In theory.

Personally, I both love and agree with that diagram, but you might as well post pictures of false prophets wearing turban shaped bomb-hats in here.

I think fuel injection is better.

# ¿ May 6, 2012 08:19

Rev. Dr. Moses P. Lester: Oct 3, 2000

CloFan posted:

So uh.. https://www.youtube.com/watch?v=xlkfZRPvg1k Any idea what that sound means? I'm getting spark on the right side and if I go from open to closed on that side's lever a couple of times the engine will finally rev, usually accompanied by a couple backfires. That may be because I'm manipulating the RPMs unevenly, though. Also, the bike won't start/run with a full rich mixture, as shown at the end of the video. I recently replaced the choke plates (both previously were broken), and I'm sure I installed them the correct way.

Good news is I put something in the garage to be a little bit more organized!

Your right cylinder isn't firing. The sound change is just the sound you hear when the right side throttle is open vs closed. You got some kinda air/fuel issue on the right carb.

# ¿ May 8, 2012 03:45

Rev. Dr. Moses P. Lester: Oct 3, 2000

CloFan posted:

Adjusting valves: I was adjusting my valves tonight, and I got my intake side fine but when I got to my exhaust I couldn't get the .004 (or any) feeler in between the pieces no matter the adjustment. What am I doing wrong?

Are you at TDCC on the cylinder you're checking? Or at least, are the cam lobes on that cylinder pointing away from the rocker arms? Sounds like that valve is just open right now because a lobe is pushing on it.

# ¿ May 15, 2012 05:55

Rev. Dr. Moses P. Lester: Oct 3, 2000

n8r posted:

I don't think there is any reason that if this bike is in good running/riding condition that it won't stay that way with relatively minimal maintenance.

This is the key point. It must already be in good running condition. No issues. "Just needs a carb clean/tuning" is an issue.

# ¿ May 16, 2012 03:25

Rev. Dr. Moses P. Lester: Oct 3, 2000

BlackLaser posted:

Dear previous owner,

You may find this hard to believe but there are things in this world that cannot be fixed with red RTV.

Welp Oil pump is leaking, lets slather it with RTV. Front brake pad, hmmm what that needs is some RTV!

You're crazy. I bought a starter for my Guzzi that was from france so it was $150 cheaper than the original ones but it didn't quite fit so I had to grind off a part of the housing and then it had a big hole in it right on the top where rain would get in so I just smeared a few tablespoons of RTV over it and it works great 3 years later!

# ¿ May 17, 2012 19:15

Rev. Dr. Moses P. Lester: Oct 3, 2000

GnarlyCharlie4u posted:

HAHA british_bikes.jpg

That's so true. I tore down a BSA for the first time last summer and discovered left hand bolts in totally random places. I could see no logic to it. As if the guys in Birmingham just got drunk and tossed coins to see what direction each bolt would go.

# ¿ Jun 1, 2012 18:41

Rev. Dr. Moses P. Lester: Oct 3, 2000

Reminds me of when I saw Peter Nettesheim, a famous BMW bike collector, talking about the first BMW, a 1923 R32. He said he found an original owners manual for it which said that you should richen the mixture when climbing a large hill. And when you get to the top of the hill, you'll have more carbon buildup than usual in the combustion chamber, because of the rich mixture. So when you get to the top of the hill you should remove the cylinders to decarbonize them.

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# ¿ Jun 2, 2012 21:41

Rev. Dr. Moses P. Lester: Oct 3, 2000

SKS is just a bearing manufacturer. Not specific to bikes. I'd get whatever type of bearings seems to be the generally accepted best replacement by people who know about that bike.

edit: er, hold on. SKS? Not SKF? Nevermind, I don't know what you're talking about.

# ¿ Jun 4, 2012 00:11

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# ¿ May 23, 2024 12:22

Rev. Dr. Moses P. Lester: Oct 3, 2000

Bloody Queef posted:

Alternatively you feel like a complete dumb rear end when your bike stalls in traffic and you're kicking the living crap out of it and it won't start.

It's even more fun on vintage BMWs where the kicker isn't even designed to be kickable while sitting on the bike.

# ¿ Jun 5, 2012 04:09

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