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Old 02-23-2012, 07:40 AM   #1
ricochetrider OP
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1993 R100 RS Valve question?

Howdy guys.
As per the thread title, I have a 93 RS. It has roughly 50K on. Last summer, I got up with some new-found friends, one of whom has an 84 RS. Boy! His bike sounded rock solid, while mine is a little rattle-y by comparison. Until our bikes were sitting side by side, idling together, I never gave it a thought as my bike runs well. I'll check with him, but I'm pretty certain both bikes have all stock set-ups, as far as carbs & exhausts.

What's the diff? What can I do to lose the rattles and tighten things up? A simple valve adjustment, or is there a known upgrade, or set of upgrades for me?

I'm not so sure I want to get into a full re-build here, BTW. But will, if that's the solution. I feel like, at 50K +/-, I should have many miles of smiles on the ol girl.

THANKS!
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Old 02-23-2012, 10:06 AM   #2
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I get this at my shop a lot. Some engines are noisier than others and very often nothing is wrong with them. I have been around and rebuilt tons of them. You never know. The last engine I rebuilt was a 750/6 from the mains out. It is still about the quietest /6 I have ever heard run but I know from experience that a little luck is involved with that.

My current bike had a noisy right cylinder when I got it with 28,000 miles on it. I took it apart to fix oil leaks and replace a bad lifter/cam lobe. The right piston/cylinder was loose. 73,000 hard miles later that included always revving it to 8,000rpm and sometimes higher, I took it apart because I had worn out exhaust guides. That cylinder/piston was the same as I left it which is probably how the factory shipped it. It was clanking when hot the whole time. Well, this time one of my pistons had a compression ring groove just starting to wear plus most of my cross hatch was mostly gone so I got new cylinder/pistons. I haven't ridden it enough yet to now if it is still noisy or not.

Engine noise: A lot of it comes from the valve lash. A lot of people think they are adjusting them to .004 and .008 when they are really adjusting them to .009 and .014. Remember, it isn't .008 until a .009 is too tight. AFTER you tighten the lock nut and while you are pushing hard on the adjuster to remove valve train slop!

Rocker arm axial play. There is almost never a need to shim the shimmed rockers. They will adjust just like the older type if they aren't way off. BTDT a Mcmillion times. I have worked with others that have done the same.

At your mileage a new timing chain and crank sprocket will probably help. Or you can wait a bit until you really need it. It won't be that much longer.

Carb sync and timing make a difference too! It's a lot more subtle but it does matter.

Good luck!

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Old 02-23-2012, 11:26 AM   #3
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You're sure it's not the fairing thats rattling. Right?

Get down and really listen to the bike before yous start tearing things apart. Most of the time the fix is a new timing chain, but the first thing I'd do is to check is for a sympathetic rattle from the gear box. One of my old R90 gearboxes rattled and while it worked well, the noise drove me crazy!

Make sure that the bikes tuned correctly and if the problem persists, pull the covers and check the chain and sprockets. If you're lucky, you won't need sprockets. A smooth rolling timing chain is a wonderful thing!
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Old 02-23-2012, 11:49 AM   #4
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I remember once I was adjusting rocker arm play on a oilhead to fix a noise. I said sure but as long as everyone knows it won't help. Oilheads aren't like airheads in this way. Do it anyway I was told. Later that day I was outside rolling in the next bike to work on and I saw that customer rolling in. I went up to him before he even shut off his engine and asked if the noise was still there and he said yes. I reached up and pulled in his clutch and asked him if that fixed it. You should have seen the look on his face! I tried but my fix wouldn't make the shop any money. In the short run!!

A mechanic's stethoscope with the metal rod removed works wonders for locating noises. Just point the little cup that is there in different directions and it will get you there in no time.
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Old 02-23-2012, 01:13 PM   #5
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Yeah...

I was thinking the same thing but forgot to mention using a stethoscope.

Good idea!
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Old 02-23-2012, 02:30 PM   #6
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Quote:
Originally Posted by mymindsok View Post
Yeah...

I was think the same thing but forgot to mention using a stethoscope.

Good idea!
+1 on the stethoscope. Rare was the day in my shop when it wasn't used lots. Your can hear the rumblings of failure lots of miles before. Very useful feedback from cheapo HF goods.

Faring creaks and squeeks??? A small rubber faced hammer or just the heel of your hand tapping around and about while on the center stand will help find them.
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Old 02-24-2012, 05:49 AM   #7
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A loose fuel cap can sound suspiciously like a BAD fairing rattle!
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Old 02-24-2012, 07:45 PM   #8
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My rattles definitely aren't coming from either the fuel cap or the fairing. I'll check the timing chain and gear. I'll see if I can find a stethoscope to use on it- great idea, my auto mechanic has one. Thanks for the replies, everyone.

BTW actual mileage is slightly under 53K- 526700, or thereabouts.
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Old 02-24-2012, 10:03 PM   #9
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At 50k you're overdue for a top end overhaul. New valves and guides make a big difference if yours are worn.

Camchains - Don't just swap the camchain on its own. The engine sprocket needs changing as well if it's a single row chain.

Clutch rattles can add to the cacofany so it's worth balancing the cards and making sure the splines are lubed.
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Old 02-25-2012, 12:37 AM   #10
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Quote:
What can I do to lose the rattles...
Earplugs...
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Old 02-25-2012, 01:10 AM   #11
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Quote:
Originally Posted by ricochetrider View Post
What can I do to lose the rattles
Add 10 speakers ???
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Old 02-25-2012, 11:34 AM   #12
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Quote:
Originally Posted by Bill Harris View Post
Earplugs...
Nice try bro- but I'll STILL have to put up with my brain rattling around in there!

Quote:
Originally Posted by R100LT View Post
Add 10 speakers ???
Let me guess- you're a guitar player? Single most oft cited fix by guitar players- turn it up.

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Old 02-25-2012, 11:51 AM   #13
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So, realistically-

A: Valves and guides

from Supershaft:
Engine noise: A lot of it comes from the valve lash. A lot of people think they are adjusting them to .004 and .008 when they are really adjusting them to .009 and .014. Remember, it isn't .008 until a .009 is too tight. AFTER you tighten the lock nut and while you are pushing hard on the adjuster to remove valve train slop!

Rocker arm axial play. There is almost never a need to shim the shimmed rockers. They will adjust just like the older type if they aren't way off. BTDT a Mcmillion times. I have worked with others that have done the same.

B: Cam (timing?) chain & gear/sprocket

C: Spline lube.

D: And also possibly check carb synch?

How do I know for sure I need a valve job? Are there specific tolerances I need to be aware of on this?
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Old 02-25-2012, 12:02 PM   #14
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Valve and guide wear vary too much to put a mileage on when you are over do for work. They often are just fine for way longer and sometimes need it sooner. How do you keep track of your heads? Keeping track of your valve lash and leak down testing.

Spline lube has nothing to do with tranny/clutch rattle. That noise is from the clutch rod bouncing around because of its free play. You can get ride of your free play but that is kinda hard on your clutch and throwout bearing. You can just pull in your clutch to see if that is the noise you are hearing.
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Old 02-25-2012, 03:36 PM   #15
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I have found that both the gas tank "lever" and the "air snorkels" rattle and make surprisingly loud noises that can be heard over the engine when running.

Boxerboy has mentioned these in previous posts and I too found they both added to the mix of noises. If you perform a good valve and carb adjustment and still have unknown noises it is worth checking them. Bill.
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