bmw k100 timing help

[curtishiser]

i have 1985 bmw k100 I had to do the head gasket on it ended up getting a new timing chain and new gasket for a bunch of other things. Got the head gasket and all the other stuff done. It just seams like I cant get the timing chain in the right spot according to the shop manual. I've looked all over the internet to try and find how the the timing marks are suppose to line up and cant find anything on the topic. The marks are either offset from where the book wants them by one tooth in either direction or im doing something wrong. I have all genuine bmw parts from the dealer and this chain just wont let me align anything how the book says. Help me please.

[Kaos]

i have 1985 bmw k100 I had to do the head gasket on it ended up getting a new timing chain and new gasket for a bunch of other things. Got the head gasket and all the other stuff done. It just seams like I cant get the timing chain in the right spot according to the shop manual. I've looked all over the internet to try and find how the the timing marks are suppose to line up and cant find anything on the topic. The marks are either offset from where the book wants them by one tooth in either direction or im doing something wrong. I have all genuine bmw parts from the dealer and this chain just wont let me align anything how the book says. Help me please.

Okay this is either going to be really shitty for you or easy, depending on if you already have your cylinder head removed or still have to.
If you still have to: I drew a pointer, one down, one up facing eachother with a ruler, same for the camshaft, and then made sure everything alligned when reinstalling.

Now if you have already removed everything then its going to be a pickle.
however, manageble.
Your upper (inlet) and down (exhaust) camshaft have a cutout in the cogwheel. These need to be alligned. The camshaft down needs to have the cutout facing up, and above facing down.


afbeelding_2025-03-15_172732200.png (37.47 kB . 267x260 - viewed 406 times)

Your pistons 1 and 4 need to be in their most outward position where 2 and 3 have to be at their deepest when installing them. This should set your timing correct.

IF you have to move the pistons to their position do so setting the bike in neutral anb use an 8mm allan (or was it 6?) anway, on the bold for the crankshaft, this should keep your hall sensor alligned
In the scanario of you having removed the hall cog, the cutout on that cog should be facing upward when you have met all the above criteria

[Laitch]

Count the number of links on both chains. Do you get the same number of links? Are the lengths of the chains the same?

[Kaos]

After reading liatch's comment i've come to the conclusion that i've red the issue incorrectly.

So yeah, make sure the chain has equal length/
Links

The one click off is the same thing I faced after replacing my cylinder head initially with the original chain. I ended up correcting by putting the chain on the camshaft sprocket before bolting down the holding thingemies and then bringing the chain up to tention.

[alabrew]

It just seams like I cant get the timing chain in the right spot according to the shop manual. I've looked all over the internet to try and find how the the timing marks are suppose to line up and cant find anything on the topic. The marks are either offset from where the book wants them by one tooth in either direction or im doing something wrong.

I'm slow, so more info would be appreciated.

The biggest problem I've had in this area, was getting the chain tensioner locked, and keeping it locked in the non-tension position.

Going off memory, you put cylinder 1 at top dead center.
The cam shafts need to aligned so that the slots on the far ends are parallel, there is a holding tool for this, but I've not needed it.
Both valves in #1 closed.
The cam gears have a pin to align them.
The chain should then slip over the cam gears and the part between can be installed. (can't remember name of this part)
The chain tensioner can be then released.

This off memory...my manual lost in tornado.

Please correct

[Kaos]

this should be the order for installing the camshafts and setting the timing.
I've typed this really slow for you 

-"Going off memory, you put cylinder 1 at top dead center.": correct (by rotating the crankshaft)
- when not installed, install the camshafts - top intake, down for exhaust, and allign the timing marks
  Timing mark for exhaust, facing top dead center, and intake for facing Down dead center - i dont know if thats a thing "down dead center", but i guess it gets the point across
- Install the bearing caps for the camshafts, torqued to spec. (this is how it should be done)
- Place the timing chain over the camshaft sprockets and the crankshaft sprocket. Ensure the chain is properly seated on the sprockets
- then if not installed (I reckon it isnt, otherwise its impossible to get the chain around the sprockets install the tensioner
   to adjust the tensioner, you may need to release the tension first. This is done by compressing the spring inside the tensioner. you might want to use a screwdriver or something similar to compress the spring
   Once the tension is released, adjust the tensioner to ensure the timing chain is properly tensioned. The chain should have minimal slack but should not be overly tight
   setting the tension can be done by releasing or increasing spring tension on the tensioner. max compression is the most released state of tension, increasing the release of the spring sets a higher tension.
  if i remember correctly the last part was frustrating because I've had to do it couple of times since the tension can not be decreased after releasing the spring tension, which makes you have to start on max a maximum compressed spring again.

I think that's it.

When it comes to a service manual, fear not: https://www.bskspeedworks.co.uk/downloads/k75%20-%20k100%20LT%20all%202v%20models%20repair%20manual.pdf
I think one of the moderators here (eyeballing Liatch) can probably also point you to a digital munual stashed somewhere on the Forum

[Laitch]

When it comes to a service manual, fear not: https://www.bskspeedworks.co.uk/downloads/k75%20-%20k100%20LT%20all%202v%20models%20repair%20manual.pdf
I think one of the moderators here (eyeballing Liatch) can probably also point you to a digital munual stashed somewhere on the Forum

There's been one in the Technical Directory here for years. I use a Clymer or a Haynes, too, when searching for the most understandable diagrams and halftone photo reproductions.