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1987 K75S, tight valve.

dieselyoda

Active member
I'm doing some long needed TLC to a 1987 K75S with 67,000 miles that includes a good tune-up. Since it's bucket and shims for the valves, I thought a thorough check of clearances was all that was required.

The specs I have for intake clearances is 0.006" to 0.008", a universal intake dimension. Bear with me, I am now comfortable the specs are accurate. I use a 0.006" feeler gauge as my "Go" and the 0.008" as my "no Go"

I get to #1 intake and I'm a "no Go" at 0.006". I'm a "Go" at 0.003" but close to a "no Go" at 0.004" and definitely 0.005" won't go.

This is the intake so I doubt I've got a cupped valve, compression and leak down were great. I'm now concerned I have a pulled stem.

The question: Do I change the shim to gain clearance or do I assume I have a pulled stem?

Next question: Do these engines drop valves?

There are some engines I'd be yanking the head and replacing all the valves if I saw this because I know they drop valves. Camshaft lobes don't grow. Add a moderate amount of wear to the camshaft lobe, maybe 0.001" max without case harden break through, I'm thinking this engine is necking the stem by 0.002".

I feel like I'm gambling with this one and the only place I gamble is Vegas and I know I will loose there most of the time. I don't want to gamble on this one.

Then again, I might be the only person that ever checked and it's been like that from the assembly line...........

Thoughts? They are very much appreciated.
 
Change the shim. It is not uncommon for the intakes to tighten a little, however the exhausts have tightened more often on my 91 75RT. I would do all the valves and run it for 5000 miles or so and recheck.
 
Not a problem, change the shim. Valves and valve seats do wear with normal use causing the clearance to decrease.
 
these engines rarely drop valves. They need so little care owners usually neglect checking them for 50k miles and then they might burn a tight exhaust valve.
 
Yoda,


It is kind of unusual to have an intake tighten up that much without the exhausts moving. Maybe the last person that was in there made a mistake in calculating the shim, went the wrong way, and didn't double check after the new shim was in.:dunno

Since it is YOUR first time inside this particular bike, I would reset them so that YOU are sure that they are correct and see where things go in about 5k miles. Have not heard of any K75s dropping valves. I wouldn't worry.

Shims come in approx. 002" (.05mm) increments.

If you don't already have the shim tools or don't want to spring for the more expensive ones because you don't anticipate using them much, there used to be a guy that was making them. Don't know if he is still making them. You'd need to call or email him first to check. The quality was good for keeping a couple of bikes in shape for their life time. If you were going to make your living doing valve adjustments, you'd want the better ones. Kind of a Snap-on vs Harbor Freight kinda deal.

Here's my comunication with him from 6 years ago:

Hi Lee
Yes, I have BMW "K" engine Valve Adj tools available for the 2 valve "K" engine.
The 2 Pieces are made from 3/16? Laser cut steel. Working contours are identical to factory tools. Tools are new. Tools come w/ instruction sheet.
$27 S/H included.
Clutch pilots for K's are available also. New, from steel
$18 S/H included.
?Pay Pal? to Polepenhollow, Cashiers Checks, Money Orders and Personal Checks accepted.
I ship as soon as Pay Pal is posted or the check arrives.

Thanks, Good Luck and Good Riding.
Kenneth Lively
318 S Hart St
Palatine Il 60067

polepenhollow@yahoo.com
847-561-8555




:dance:dance:dance
 
I agree you need to get to a known base line. Without knowing the service history of the bike it is hard to tell what might be going on. My first K75 got one shim at 600 miles, and needed another (different valve) at 60K miles, then a third at 100K or so. It is possible that the seat moved a little and the valve hasn't been checked since that happened. In theory this settling in is all supposed to happen before the 600 mile service but; 1) it doesn't always happen that way, and 2) some frugal buyers neglect routine services.
 
Thanks for the advice, I'm going to take it and run

Bringing the valve clearances to a known good value and running awhile makes sense.

Tight intake valves on most engines would make me nervous but if dropping valves on this engine isn't likely, a few thousand miles should tell me if I have a problem. That might be entire season on this bike.
 
Yoda,

Your plan, good it is.:brow


02 11 12 1 460 622 GASKET (outer) 1 req. $8.51

03 11 12 1 460 623 GASKET (inner) 1 req. $8.51


05 11 12 1 460 368 PLUG (cam end) 2 req. $2.64 ea.


06 11 14 1 460 934 BUSH (bolt) 10 req. $0.71 ea.



While it is nice to replace all the valve cover gaskets at least once when you first get a 27 year old bike opened up, the two main gaskets and the two cam plug half moons will usually be reusable for MANY cycles of valve checks. The MOST critical is the rubber bolt bushings. The valve cover bolts bottom out (72-84 IN/lb) on the shoulder. It is the elasticity of the bushings that applies the clamping force to the gaskets. The bushings get hard and stiff from the heat and loose their clamping ability. If nothing else, try to replace those if they appear to be hardning.




:dance:dance:dance
 
Bought the consumables a month ago.

I faced off the shim this afternoon, got a nice 0.0075" clearance, back together, will report if she blows!

In my career, I wouldn't be comfortable with a tight intake but I don't make a living fixing motorcycles. I'm OK following the advice you have given here.
 
Maybe I'm off base here, since I'm not a metallurgist, but aren't the shims surface-hardened?
If a surface is milled (and is this the same as "faced off"?), you lose that hardening, and the shim will now wear more quickly.
 
Maybe I'm off base here, since I'm not a metallurgist, but aren't the shims surface-hardened?
If a surface is milled (and is this the same as "faced off"?), you lose that hardening, and the shim will now wear more quickly.

To point, you are correct. Most case hardening is about 0.006" thick in my experiences. If I used a carbide cutter, not only is the cutter hard to control at the thickness I took off but generates a lot of heat which could damage the case hardening.

I used diamond grit paste on a lapping wheel and let it go for several hours. I didn't have much choice as there is no exchange program for shims at my BMW dealer and they would only sell me a new one, which was a week away. There is another story there about how hard it is to deal with my dealership.

If I had gone through the case hardening, I would have place the softer surface bucket side down and taken my chances.
 
Shims are less that $5 each. I just keep the old ones in case I need it on a different valve.
 
You don't know how lucky you are to have dealers close to you.

Shims SHOULD be $7.20 NEW from the dealer. This dealer won't sell his "service" inventory and shims are not considered routine stock items and emergency supply only. The have an "engine down" policy for parts like this. I could have packed the bike up to them, completely assembled, determine the valve was tight and repaired it.

Ready for this?

The shim, special order, "engine down rush", ten days to supply, $52.00.

The quote on repair, not to mention I have the bike in about two hundred pieces still and would have to trailer it as it needs to be safetied for licensing, just their quote, parts and labor, $680.00. They might be able to get to it in June if I brought it in right away.

I am not exaggerating. They are the only dealer within an 800 mile radius. The closest other dealer to me is in Minneapolis or Saskatoon and the Saskatoon dealer is tiny.

Where possible, I use the 'Net dealers.

This dealer knows he is the only game in town.
 
I believe that there are some Japanese bikes that use the same diameter shim and that they can be interchanged. I haven't done it but if it is possible I am sure that someone else has.
 
I believe that there are some Japanese bikes that use the same diameter shim and that they can be interchanged. See note from Internet BMW Riders website as follows:

Yamaha/Kawasaki shims for 2-valve K shims

Date: Tue, 18 Nov 1997 11:04:23 -0700 (MST)
From: Tony Black <TBLACK@cc.colorado.edu>

One item did come up I want to let owners know about. If you need a shim for your 2 valve K and you don't have a dealer close by, shims from some models of Yamahas and Kawasakis will fit in the Ks. If you have one of these dealers closer I'd use them. I have many times on my bikes and others. Ciao Tony
 
Kawasaki and Yamaha use the same shims, mostly, however,

My BMW dealer is also the only Yamaha dealer and since I don't actually have a Yamaha, they wouldn't reverse part look-up, at all. I even gave them the part number.

The Kawasaki dealer said he would look for it and probably had some inventory but strongly suggested that their shims were just slightly smaller in diameter enough that I might not be a happy camper. He reasoned that they have sold them for Yamaha guys that complained they "stuck" in the bucket causing, well, bad things.

Facing the shim off, drinking beer and crying with my buddies that the Jets didn't come close to being play-off hopefuls was a good alternative. If I was a Leafs fan, all I can say is with all the beer in the city and successful experimenting with a shim, I'd still be drinking and crying.
 
Shims SHOULD be $7.20 NEW from the dealer. This dealer won't sell his "service" inventory and shims are not considered routine stock items and emergency supply only. The have an "engine down" policy for parts like this. I could have packed the bike up to them, completely assembled, determine the valve was tight and repaired it.

Ready for this?

The shim, special order, "engine down rush", ten days to supply, $52.00.

The quote on repair, not to mention I have the bike in about two hundred pieces still and would have to trailer it as it needs to be safetied for licensing, just their quote, parts and labor, $680.00. They might be able to get to it in June if I brought it in right away.

I am not exaggerating. They are the only dealer within an 800 mile radius. The closest other dealer to me is in Minneapolis or Saskatoon and the Saskatoon dealer is tiny.

Where possible, I use the 'Net dealers.

This dealer knows he is the only game in town.

Good grief. I would complain to BMW that they will not stock shims for sale. That is not providing service. They are clearly trying to force you bring in your bike. How does buying mail order from Max BWM work from Canada? You can order a few of the common sizes to keep handy.
 
I use Max, A&S and Capital is the best, Tommy is a pretty good dude.

I use them all, I really don't have a particular loyalty, I like Tommy though, he takes some time for me to chat. The problem, as I see it, the USA still wants to do business with us but Canada, we are still taking our pound of flesh out of YOU because Bush snubbed us at 911.

I send all my stuff to a wonderful little gig in the US and drive down, grab it, and get FUTRE when I cross into Canada.

For a bit of perspective, you, my neighbours, are 240 Million strong(?) and we are just about 10% of that. Do you really think BMW Mottarad Canada gives a crap about me?

It would cost me $500.00 to get a recall notification on any BMW motorcycle I buy second hand. That's from the dealer. I need all the recalls to be completed to date in Canada before I can take it to be Safetied.

I love my country, I love my country, I love my country, why did my Dad move to the US again?
 
First, good on ya for the workaround! "Necessity is the mother of invention", but sometimes necessity is just a mother... keep an eye on that particular valve's clearance in the future...

Second - Wow, that dealer is really screwing you (and probably all your riding neighbors), to diplomatically understate it. He won't look up a Yamaha part because you don't own a Yamaha? (There probably is no official cross-reference between brands.) That's not just narrow-minded, it's downright rude (aside from his choice to not make a sale). $500 just to look up recalls? I thought that was a FREE thing; all they do is put your VIN into their computer (or maybe it's because I patronize a few specific dealers down here, yes it's nice to have a choice). You might also be able to check your bike in the National Highway Safety Administration website, http://www-odi.nhtsa.dot.gov/cars/problems/recalls/ Or do they want $500 to verify that any recalls have actually been fixed? Also out of line.

More than one BMW dealer has been shut down, or at least been fined, after corporate investigation. Certainly you don't want to lose a viable parts source, but BMW North America Corporate (New Jersey) should be made aware of this guy. And I'm fairly sure that even Yamaha Corporate (near here, in Buena Park CA) would like to know that one of their dealers refuses to not only sell Yamaha parts, but won't help out a fellow rider. There are several multi-brand dealers around here; if you pull in with something they don't sell, they still usually don't defecate in your face.
 
Good grief. I would complain to BMW that they will not stock shims for sale. That is not providing service. They are clearly trying to force you bring in your bike. How does buying mail order from Max BWM work from Canada? You can order a few of the common sizes to keep handy.

good grief is right. That dealer not stocking shims for a bike that has been out of production for nearly 20 years is just reedickulous. of course, Honkawsuzimaha would not have waited nearly that long to clear their shelves of NOS parts. smh.
 
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