Hi Everyone,

I checked my valve clearance and my intake was a little tight at .13 mm for 3 of the 4 shims.  When removed and measured with a vernier caliper all shims were 2.40mm.  They were replaced with 2.35mm and the gap is within spec now...

The exhaust which should be .25mm was as follows

#1

.10mm clearance

Shim: 2.65mm

New shim: 2.50mm

#2

Under .04mm clearance

Shim: 2.60 mm

New shim: 2.40mm

#3

.05mm clearance

Shim: 2.65mm

New shim: 2.45mm

#4

.05mm valve clearance

Shim: 2.65mm

New shim: 2.45mm


My questions are

#1 Is my math correct for the new shims I bought?

#2 when I measured the valve clearance after replacing the exhaust valve shims there is virtuall no change and it seems they aren't seated right as some are reading under .04mm clearance.  

I ran the starter for a few revolutions with the spark plugs out of the bike to see if that would seat the shims properly (after getting them into correct position by hand) with no change, I also did this by hand with a wrench before trying the starter.  I then buttoned up the valve cover and started the bike and warmed it up.  It didn't help anything either.  I will check again tomorrow when the bike is cool to see if anything has changed.  I'm assuming the valve buckets haven't seated to the shims properly even though they are in place.   Is this correct and how would I go about fixing this?

Regards,

James

You should measure shims with a micrometer, using a vernier caliper wont give a true reading if the shim is worn in the centre and therefore not to be used.

Regardless of that,  the new shim size is smaller and should be resulting in a larger clearance than the perceived error from measuring with a vernier caliper.

All the thinking there is correct. What year is the bike because if it was built for leaded fuel the unleaded will cause havoc with the exhaust valve seats.
83 and some of 84 were the years involved but being in the US they didn't appear there till 85 but after 30 years anything can happen with swapped engines.
P.S. the engine number is a better guide as to year of production.

Hey Rick thanks for the help,

It's an 84 but title says 85 so yes to leaded.

I was talking to a friend who said it's an aluminum engine so the valve seats have to be hardened regardless.  Is this true?

Bekman wrote:Is this correct and how would I go about fixing this?

Those exhaust valves are excessively tight and with those clearances, damage would occur to the engine sooner than later if run that way. How many miles have you put on this engine? 

I'm wondering about your procedural technique. Describe the tools you are using and the reference guiding your procedure. It should be obvious when the shims drop into the buckets. Starting the engine to check them could result in damage to the engine if you haven't rode herd on your tools—or other foreign objects get involved—and should be unnecessary.

Top row is intake; bottom row is exhaust. Narrow lobe positioned outward and perpendicular to the shim surface during clearance check.

Bekman wrote:Hey Rick thanks for the help,

It's an 84 but title says 85 so yes to leaded.

I was talking to a friend who said it's an aluminum engine so the valve seats have to be hardened regardless.  Is this true?

The head will have hardened seats but to run unleaded you need stellite not just hard steel.
Being an 84 it may or may not have the good valve seats. If you put the last 7 digits into the RealOEM site it will tell you month of manufacture.
http://www.realoem.com/bmw/enUS/select  You need to use classic to find the K100.

Production date is 08/1984

Chassis is 30411

Model is K100 83 (5051) (5011)


I actually just filled the tank with some ethanol free leaded race gas for winter storage for the bike...  too bad it's $10 a gallon and most likely never was used in the bike!  Also just had the injectors serviced and cleaned which apparently wasn't needed.

It looks like one of my posts didn't go through...  and it was a long one...  I'll try and do a quick recap

Tomorrow I will be checking a few things over again...

The valve buckets on the intake seem to move freely independent of the valve shims as they should be(there is a for a lack of a better term a notch that helps you pry the shim out, this can me rotated to whatever position is needed) I do not think this is happening on the exhaust.

I will also take one of the old 2.40mm intake shims and use it on the largest shim (2.50mm) and measure with a feeler gauge to see if there is a difference.  If necessary I will try one of the new 2.35mm shims from the intake.  

I bought the shims from motobins

I bought the bike very recently with 95,000.  The previous owner said he put 12,000 miles on the bike and I am worried that whole time the valves were very tight

I was originally chasing a cold start problem which I and the previous owner who had a bunch of spares for me to swap out, thought was a fi problem. I'm suprized he didn't check the valves as he said he was a mechanic by trade which also delayed me checking the valves when it should have been one of the first things to check.  Good thing I have only rode the bike around the block a handful of times.   The bike would have a hard time to maintain idle and also would struggle and bog down when trying to rev at times also with some backfiring through the throttle bodies.  But once the bike was fully at operating temp (fan on) it ran great.  So I would let it idle till fully warm if I wanted to ride it.

The exhaust can even be a bit loose which wont hurt but tight will cause problems. I think 210 is the smallest BMW shim (maybe 200) but Kawasaki z900/1000/1300 go down to 180 (caution the lip on the bucket may be too high I don't know).
I would go down till the bucket spins freely as the inlet and take it from there. Going on past reports the valves probably are recessed badly and need attention. A good used head maybe the easy alternative.
When I bought my very first K the guy said it had no compression on the two centre cylinders which turned out was very tight shims. I later asked when was the last time the shims were checked and he replied "the what". He rode that bike for around 100,000 klms (60,000 Miles) I couldn't believe it.
A production date of 8/84 is right at the change over if memory serves me right.

Bekman wrote:But once the bike was fully at operating temp (fan on) it ran great.  So I would let it idle till fully warm if I wanted to ride it.

When the fan is running, it's not only a sign that the bike is "fully warmed up" but also that the engine is approaching overheating and attempting to cool down to optimal running temperature. Once it's at operating temperature, the fan will shut off. On a well-running bike in ordinary moderate riding conditions, the fan will not be running. 

The fan will run in slow-moving traffic, long idling or in extreme temperature. Even then it should usually cycle on and off. A fan operating constantly on the open road could be a sign of chronic overheating. Tight valves can cause that. 

The notch in the bucket is called a "notch." The buckets are rotated to place their notches in the best position for loosening then extracting the shims.

How did you hold down the buckets to extract the shims?

I bought the specialty tools from Ken lively.

In regards to the fan, I was talking about at idle not moving.  It tended to run better around the time it would turn on.  It would cycle on and off as well.

In regards to the shims, yea im guessing... but it seems they have never been adjusted as all the shims were the same for the top with the same markings that could barely be seen, same for the exhaust, same markings but one had a little more wear. 

And Rick thanks for the info about the head and leaded gas for  08/84

Snobum has serial number information about the conversion of the early Bricks to accept unleaded fuel. Scroll to 4C on this page of his under the heading of Well, Enough About . . .

Well... I'm going to stick my oar in here and say that there's too much panic surrounding the use of unleaded fuel with leaded-build engines. What follows is purely my experience:-

1979 Moto Guzzi V1000G5 - 180,000+ miles on unleaded. Burnt the L/H exhaust valve but I'm pretty sure that was me neglecting maintenance
1980 Moto Guzzi 1000SP - 100,000+ miles on unleaded with no problems
1974 Moto Guzzi 850-T3 California - 17,000+ miles on unleaded with no problems. This one spent the first five years of its life drinking American fuel. Engine total was about 32,000 miles when I sold it
1978 Moto Guzzi 850-T3 California - 23,000+ miles on unleaded with no problems
1976 Moto Guzzi V50-II - 30-something-thousand before the engine blew with a casting fault
1977 Moto Guzzi V50-II - can't remember the mileage but only gave the usual V50-II problems

Bear in mind that the stated mileages were on unleaded; all bikes would have accumulated additional mileage running on leaded fuel in the early years of their lives.

1983 K100 - paperwork says about 12,000 miles on leaded and 71,000+ on unleaded. When I checked the valve clearances at approx 77,000 miles I had to replace five shims because they were only just out of tolerance.

I refuse to believe that I was 'just lucky' not to get any valve-seat related problems in all those miles.

Hey Dai,   I've heard the same thing.  I so want a 70s Guzzi next.


Back to the exhaust valves...  the buckets were fine.

I switched out the exhaust shims for the 2.35mm shims I bought for the intakes.

Then ran the starter for a few rotations to make sure the shims were seated. 

These are my results 

Exhaust #1

2.35mm shim clearance .20mm

Exhaust #2

2.35mm shim / clearance .10mm

Exhaust #3

2.35mm shim / clearance .04-.05mm

Not sure what's going on with that

Exhaust #4

2.35mm shim / clearance .13mm

So I'm going to do this...

Intake #1

2.25mm shim to keep it loose but 2.30 will be bought as well.

Intake #2

2.15mm would rather have it be loose

Probably will buy 2.20mm as well 

Intake #3

2.10mm

Intake #4

2.20mm

I'm thinking I should buy shims one more time and give it a go but it might be cost effective to just buy a know good head with good valves correct ?  Also does anyone know a cheap place for shims in the US?  Cheapest still seems to be motobins even with priority shipping

The Shims from other manufacturers should fit too.
Here is a list, no warranty.
Size should be 7,5mm.

Some Vespa Scooter should fit 2€
And
Suzuki: AN 400 Burgmann 06-09  AN 650 02-10  DL 650 V-Strom 04-10  GSF 650 Bandit 07-10  GSF 1250 07-10  GSR 600 06-10  GSX 650 08-10  GSX 1400 02-07  GSXR 600 97-10  GSXR 750 92-10  GSXR 1000 01-10  GSXR 1100 93-97  RF 600 93-96  RF 900 94-97  RM-Z 250 07-10  SFV 650 Gladius 09-10  SV 650 99-10  
Yamaha:  FZ1 1000  FZ6 600  FZR 400  FZR 600  FZR 1000  FZS 600 Fazer  FZS 1000  GTS 1000  WR 250  XJ6 600  XP 500  YZ 250 01-10  YZF 600 96-01  YZF 750 93-98  YZF 1000  R1 1000 98-06  R6 600 99-09  R7 99-00
Honda: but expensive CB 500 PC 26 und CB 500 S PC 32
Kawasaki: don't know which

Cheers

Bekman wrote:Exhaust #3
2.35mm shim / clearance .04-.05mm
Not sure what's going on with that

BMW supplies shims down to 2.00mm at $10 a pop, but if it were my bike, I'd learn what's going on with #3 before spending any more money. It seems worn out.

Do a compression test across all four.
Seems to be a few valve related issues lately.

Ok so compression test is as follows

Cylinder 1 - 95 psi
Cylinder 2 - 100 - 105 psi
Cylinder 3 - 105 psi
Cylinder 4 - 105 psi

I didn't have time today or the right tools handy to squirt some oil in the cylinders.  

Since it's an engine put on its side does the oil even temporarily seal the rings in order to check if they are worn?  I've also heard that the cylinder walls and rings normally look brand new on these engines.  Is that normally the case ?  Also what is my best bet?  A used head and valves?  Get mine rebuilt?  I know valves are expensive last time I checked.

As a work around on the high price for valves...  since this is basically the same engine as the Peugeot 104 I'm taking an educated guess that the valves would have to be the same for the 2 valve models. Looking online they are pennies compared to a BMW valve.  Can anyone confirm?

Bekman wrote:Ok so compression test is as follows

Cylinder 1 - 95 psi
Cylinder 2 - 100 - 105 psi
Cylinder 3 - 105 psi
Cylinder 4 - 105 psi

Was the test done with:
Warm or cold engine;
Closed throttle or wide open;
All spark plugs removed or only the test cylinder's removed;
Threaded test gauge or friction test gauge?

Bekman wrote:Ok so compression test is as follows
Cylinder 1 - 95 psi
Cylinder 2 - 100 - 105 psi
Cylinder 3 - 105 psi
Cylinder 4 - 105 psi

Those values are in the poor range in the BMW manual specs, even though they're relatively balanced. A leak-down test may tell why the compression is poor.

Those readings are in the poor range however they are very even so I suspect the procedure may not be correct.  If a valve is burnt or riding then the compression in that cylinder will be much lower than 100psi and often will not even register.
It is difficult to get the oil to distribute well with the horizontal bores but usually if you put a bit of oil the cylinder in and replace the plugs(use old plugs) then turn the engine over on the starter without starting (disconnect the injectors or the coils at the 12v side not the plug leads).
Then do a reading with the throttle wide open.

Laitch wrote:

Bekman wrote:Ok so compression test is as follows

Cylinder 1 - 95 psi
Cylinder 2 - 100 - 105 psi
Cylinder 3 - 105 psi
Cylinder 4 - 105 psi

Was the test done with:
Warm or cold engine;
Closed throttle or wide open;
All spark plugs removed or only the test cylinder's removed;
Threaded test gauge or friction test gauge?

Cold engine 
Closed throttle with injectors disconnected
All spark plugs removed
Threaded test gauge

If you do it with the throttle wide open the reading will be very close to spot on. You are not getting enough air to compress.

I'll give it a shot again with the throttle wide open.  I did crank it over a lot to see if the pressure would increase.  That did result in about 5 psi more throught all cylinders.  I'll see tomorrow along with the oil test hopefully.  What have you guys used to get oil all the way into the spark plug holes?

Also, rings should seal up once warmed up and bump up compression correct?

I'm leaning towards worn valves just from how tight they are but I'll test and confirm tomorrow.  I'm holding off from ordering more shims.

Bekman wrote:I did crank it over a lot . . .

Be certain your battery is fully charged before starting the procedure. The starter relay contacts may fuse if the batter is discharged from all the exercise. Dealing with that will add to costs and the work list.

I keep it on a trickle charger.  Thanks I'll keep that in mind.

Ok so these are the readings at WOT with oil in cylinders along with spark plugs in all the holes

1 - 100 psi

2 - 110 psi

3 - 115 Psi

4 - 115 psi


Readings with WOT with oil in cylinders with no spark plugs in.

1 - 100 psi

2 - 110 psi

3 - 110 psi

4 - 110 psi.

So this is looking like getting the head done.  Are there any write ups on this?  I have the Haynes book but Im wondering if there is anything else.  I've never dealt with an overhead cam and taking the head off and dealing with taking the timing chain off.  It's one of the few things that's a little daunting to me and setting the valve timing is going to have to take me a little bit to wrap my mind around. 

Also anyone have experience getting their heads rebuilt etc?

You're right about the head needing to come off. It's just nuts and bolts check everything twice or 3 times it saves on mistakes causing damage

Bekman wrote: I have the Haynes book but Im wondering if there is anything else.  

I use a Clymer and a BMW manual, too. The BMW manual can be downloaded gratis. The Clymer will need to be purchased, or borrowed. Where one isn't clear on a procedure, a different reference might be. Just a Google search with the words K100 cylinder head removal will supply plenty of references. Then, of course, you have the triage and treatment teams here—and elsewhere—standing by, sometimes.

A heat gun, penetrant and patience will help, especially on the head bolts.

Thanks.  I'll be fine with getting everything apart. Just want to make sure I get every put back together and timed correctly!!!

Anyone know a cheaper option for new valves than maxbmw?  It's a little too expensive for my intentions for the bike.  Do you think a used head and valves is the way to go?

If you need new valves get a complete head and give the valves a light lap. It will be much cheaper.

I'll be able to get to removing the head on Tuesday and I'll let you guys know what I find.

I removed the head today.  I need to get a valve spring compressor.  Thought I could compress them by hand enough to get the collets out.  I'll take a picture of the cylinder walls tomorrow too

Bekman wrote:I removed the head today.  I need to get a valve spring compressor.  Thought I could compress them by hand enough to get the collets out.  I'll take a picture of the cylinder walls tomorrow too

A G clamp can do it but you need a short length of tube to let the collets fall out......

I ended up using a large c clamp and a large oxygen sensor socket to compress the valve springs and it worked like a charm.  

I took a ton of pictures but I'll have to figure out how to post them.

It looks like they could be lapped and then adjust the valve shims.

Ideally id like to have new valve seats put in and the valves reground but I'm not sure if I can have a 3 angle
Valve job done on all the valves.

The valve guided are great and tight.

https://s950.photobucket.com/user/jamesbekman/library/

Start on page 2 with the picture of the entire head.  From there it goes from exhaust valve seat to intake seat then I tried taking 3 different pictures of each valve starting with the exhaust

Okkkkkk....

So scratch all of this...  just bought a used engine with very good compression for cheaper than it costs to have the head redone.  I don't like the way the cylinder bores look either and will be taking pictures and would like to see what you guys think.

But think of all the spare bits you've got now!  

(coat).

Thanks for the support.  And believe me I don't mind!

Is there anything better than buying motorcycle parts?

Just glad I found one for the right price

Ok the photos of the cylinder walls are up.  Please take a look and tell me what you think.