1978 r100rs rebuild

[rowens816]

Timing Chain

I haven't posted in awhile, but the rebuild on this R100RS has been creeping along. I do believe that I have accumulated every part, gasket, seal, bearing and everything else that I could possibly need.

I just pulled the crank bearing last night, and now I need to pull the chain. I have new chain, crank and cam sprockets. Someone had recommended grinding off a link to remove the chain. Yea, that is possible, but I don't think I can cover the engine enough to avoid the ground metal flying about.

Has anyone used bolt cutters on this? How did it work out?

 

[20774]

I just pulled the crank bearing last night, and now I need to pull the chain. I have new chain, crank and cam sprockets. Someone had recommended grinding off a link to remove the chain. Yea, that is possible, but I don't think I can cover the engine enough to avoid the ground metal flying about.

Has anyone used bolt cutters on this? How did it work out?

Sure, bolt cutters would work...is the head small enough to get to the link? Still better have rags covering every opening. Otherwise, use a dremel with lots of rags and maybe even use a wet/dry vacuum with the nozzle hovering right over your work area...suck all the debris away.

 

[bmwwrench]

I use a bolt cutter to cut these chains. It'll be quite easy with the motor out.

I wouldn't hesitate to use that flywheel. The tooth chipping appears minor.

 

[na cl k9]

Thanks for the close up of the flywheel

All the holes I see are finished properly which is excellent. That and the note from ÔÇ£lostboyÔÇØ about the origin of the design is enough for me to say I would run it. I have removed the starter gear ring from several /7 - /6 flywheels at the time the wheels were lightened and balanced. You can turn the ring around so that the fresh edge presents itself to the starter engagement gear. Those teeth dont look bad at all.

 

[skiteach]

"Those teeth dont look bad at all."

They certainly don't! The pictured teeth are all worn pretty evenly. Usually trouble spots are an area(s) of worn teeth, much more wear than pictured and the rest look like pictured.

 

[rowens816]

Timing Gears

I stuffed pieces of rags in every orifice, covered the studs where the jugs are missing and plugged bolt holes with the original bolts. This baby was wrapped like a surgical patient.

I ground off the timing chain with a Dremel. Not too bad. However, much to my surprise there was a Master Link on the BACK side of the chain. I salute the person who accomplished that feat!!!!! Like I said originally, someone has been here before.

The crank sprocket does show wear. It could have lasted a little longer, but the chain was streached to the limits. However, the cam sprocket does not look as bad as I thought. Of course, I have already bought both sprockets and a new chain, tensioner, etc. Yea, I know ---- so does my wife, unfortunately.

It is not in the pictures, but the cam looks GREAT. VERY little wear.

I sometime think that I am personally keeping Harbor Freight in business. Of all the bearing pullers that I have, none will work to get that damn crank sprocket off. Any suggestions?

 

[20774]

I'd be very careful when pulling the gears and to use the proper equipment. I've heard that Kukko pullers are good for the job. The Airlist shows part number 112 600. There is also supposed to be some kind of button to protect the nose of the cam/crank when pulling the gears.

Anton has a picture of the Kukko puller set on his website:

http://www.largiader.com/articles/puller.jpg

 

[rowens816]

LOL. For the price of that bearing puller, I could buy another bike. I'll keep looking around for some AMERICAN made tools.

 

[rowens816]

On 2nd thought ----- make that China.

 

[20774]

I hear ya! But this is one area that personally I wouldn't mess around. Right tool for the job they say. The last thing you want to do is mess up a crankshaft or cam tip.

 

[AntonLargiader]

On 2nd thought ----- make that China.

You're in Deland. Why not just ask Tom to pull that sprocket off for you with the right tool?

 

[rowens816]

Crank Sprocket

Anton, who is Tom?

I think I have found a puller that at least fits. Now, I'd like to learn how to protect the tip of the crank. The puller has a tapered tip, but I am reluctant to simply fit that in the end of the crank.

Someone had mentioned using a socket??? Ok, exactly how?

 

[rowens816]

Sprocket puller

What about this setup? I am very reluctant --- having never pulled this sprocket before from such a tapered crankshaft end.

I have a heat gun that goes up to 750-degrees. I'll obviously try that. The Spacer and the penny will hopefully protect. The steel spacer is like the one in my hand --- only smaller.

i'll start this in about an hour. Any "quick" thoughts?

 

[rowens816]

Success. It worked. No damage to the crank end.

 

[rowens816]

New timing chain & sprockets

The new sprocket has been pressed onto the Cam.

I am about to press the new sprocket and bearing onto the Crankshaft. Of course, the crank is still in the engine case with the flywheel attached, and the camshaft is out of the engine.

I have read somewhere that the crankshaft sprocket, the timing chain and the camshaft should be installed together as a pre-assembled unit. Is that correct?

I can understand the inflexibility of the timing chain and the inability of getting the master link on the chain AFTER the sprockets are in place. However, to install both sprockets and chain at the same time would require that I pull the flywheel and the oil pump components. Is that a correct assumption?

Otherwise, what would be the secret to installing the timing chain and master link AFTER both sprockets are already in place. FWIW, I did notice that the old chain had the master link clip installed on the backside of the chain. I'll bet that was a PITA.

I hope this makes sense to everyone else.

 

[20774]

I've not heard of the installation as a unit. I've only read about trying to get the master link installed. There are some tricks to doing that as you can imagine. I've only read about them...never done a timing chain myself...yet!

 

[na cl k9]

the new sprocket has been pressed onto the cam.

I am about to press the new sprocket and bearing onto the crankshaft. Of course, the crank is still in the engine case with the flywheel attached, and the camshaft is out of the engine.

I have read somewhere that the crankshaft sprocket, the timing chain and the camshaft should be installed together as a pre-assembled unit. Is that correct?.

There is very little room for error using an endless chain - If you install the crank sprocket on the crank with the new chain in place and it seats before the cam is all the way in the block too, the new chain will actually hold the cam at an angle in the case preventing it from seating in the rear cam support bore. That will cost you your new ENDLESS OEM chain. If you use a master link chain the above does not apply.

fwiw, i did notice that the old chain had the master link clip installed on the backside of the chain. I'll bet that was a pita..

The master link clip installs on the back side of the chain because it doesn't clear the inside front of the chain case cover. It is installed with the closed end in the direction of travel and yes, it can be a 'pita' especially since when the master link clip slips from your grasp (as it will at least once) it heads straight to oil return holes leading to the sump....(where it sat waiting for me to unbolt the oil pan and retrieve it the first time I installed a master link chain).

 

[bikerfish1100]

I have acquired a 1978 R100RS "Project". This is my 2nd BMW, but the 1st one was the 1974 R90S in that burnt orange. Sure wish I still had that one.

Has anyone seen this flywheel before? This cannot be stock?

hey, i just found one too!!

this is my '78 R100S

that i had purchased in 1980 from the original owner with about 6,000 miles. got crashed on it 3 months later, totaled the bike. sold drivetrain to a friend, who rode it for about 4 years and brought the mileage up to (a claimed 40,000, but he never ran a speedo on it) - looked like this when he had it (he eventually put the dual disc setup on it).

.
he sold it back to me a number (LARGE #) of years ago, and am now in process of resurrecting it (will do a new thread on it once finished). needed to do a spline lube as I had last used the "then recommended" Anti-Seize on it, and wanted to get something better on there... so since i was in that dep anyway, figured I might as well do the rear main and oil pump seals.
lo and behold- i have my own version of a (German?) Swiss cheesed flywheel. i did not know that. makes me wonder if he (my friend was a bike/car mechanic) had done any other hopups to it. hmmm?

(Dap Spackled - thanks for some more impetus to get my project going again!)

 

[rowens816]

LOL. That's a cool looking flywheel. I'll bet that bike will be quick rev'ing.

SWure, this project is BOTH fun and frustrating. I am anxious to finish so that I can do some riding, but I am also cautious to assure that things get checked and corrected. This week should produce some progress. I hope to get quite a bit of re-assembly accomplished.

Naturally, I will be posting additional commentary and pictures.

 

[rowens816]

Timing Chain Master Link

Here is a tidbit of information that might help someone someday:

I just replaced the duplex timing chain, tensioner, crankshaft sprocket and camshaft sprocket. With the engine out of the frame for a rebuild, it was not that difficult. Th crank sprocket and bearing were pressed onto the crank with a shop press. The cam had been removed, the flywheel had been re-installed and blocked in the press.

The sprocket had been heated via the sun. Here in Florida, that seems to be hot enough. It pressed on without difficulty.

Same with the cam sprocket.

Then, I pulled the flywheel, and pulled the cover to the oil pump. Re-installed the camshaft with the new sprocket (with all the recommended lubricants). Installed the oil pump rotor, woodruff key, & oil pump cover.

Now, for the tough part ---- the duplex timing chain. After lining up the timing marks on the crank and cam, I threaded the chain around both sprockets.

The master link for this chain has the two small circlips. I would rather have the fish clip, but there are no reported problems with the circlips from the crowd I run with.

The trick part is getting the two ends of the new chain to meet arount 10 o'clock. The master link is installed from the FRONT. That means I have to get TWO plates on the link from the READ of the chain before the clips can be mounted. There is very, very little clearance.

I cut a 6" piece of clothes hanger. I beat one end of it flat, and bend the end to about 75-degrees. With a little Moly 60, I could stick the link plates to this flattened piece of clothes hanger, position the clips from the rear, and PULL then onto the master link. A tiny screwdriver and the same Moly 60 helped position the two circlips onto the master.

Total job took about 30 minutes. Yea, I was surprised also.