no compression at all either cylinder!

[pauls1150]

re the arrows - When the engine is assembled correctly, those arrows are used for setting the valves, instead of trying to find a mark on the flywheel. Turn the engine over manually (either by the front nut or the rear wheel, using 5th gear) in the normal direction of rotation (to take up any cam chain slack) until the arrow points straight out horizontally, at either the 9:00 o'clock position (left side as viewed from the rear) or the 3:00 o'clock position (right side as viewed from the rear). That will put you on the "flat" of the cam - but you still need to determine if that cylinder is actually at TDC, or at overlap (as explained by d'Yoda). The actual TDC side should have a little "wiggle" if you grab & jiggle both of the rockers, and this side is ready to adjust, while the overlap side will not have wiggle, it should feel tight ... assuming that they are "in the ballpark" to begin with. Set the valves one RCH loose just to be sure they can fully close, turn the engine over 360 degrees, and you should be set to do the other side.

 

[K7GLE]

I didn't even know both pistons were at tdc at the same time.

Not quite - they're 180 degrees out of synch: When one is at TDC (top of compression stroke, all valves closed) the other is at top of exhaust stroke (exhaust valves open).

 

[pauls1150]

My caffeine hasn't kicked in yet ... should my earlier "360" actually be "180 or 540" ?

 

[20774]

In my world, when the pistons are all the way out, that is top dead center. Doesn't matter if it's compression stroke, exhaust stroke, whatever. It's TDC.

Setting valves are always done at TDC on the compression stroke for the cylinder under investigation. Oilheads should be the same as Airheads...once you've found TDC on the compression stroke for one side, turning the engine/flywheel 360 degrees to the next indication of TDC will be TDC on the compression stroke for the other side.

I always am a little leery of the idea of finding TDC in the window and checking for which set of valves are loose. It's not necessarily true that one or the other valves will be loose. If the clearance has significantly tightened up, none of the valves will be loose. So, the best way is to watch the valve action to know when the intake stroke is complete and the piston is on the way up to TDC compressing the mixture. Or remove a plug and put your thumb over the hole and feel for the increase in pressure. The next time TDC shows up will be the end of the compression stroke for that cylinder.

 

[pglaves]

Clarification: the pistons go out at the same time and in at the same time. While it may be semantics they are at TDC - as far toward the head as physically possible - at the same time. But as was stated one cylinder is on the compression stroke with both valves fully closed while the other cylinder is just finishing exhausting the exhaust and beginning the next intake stroke as the piston retreats from its position away from the head.

 

[rxcrider]

The following information is for the R1100xx, but if memory serves, the same is true for the R1150xx:

 

[m_stock10506]

Yes, that is correct for the 1100 motor - I personally can't confirm it is also true for the 1150. I use this method whenever I am checking valve clearances. This method is MUCH easier than using the timing hole and watching for OT. Also I can't stand trying to put that PITA timing hole cover back on and trying not to push it into the flywheel space. There are too many parts in the way and not enough space to work in there.

The only "correction" to the diagram that I have is in every R1100 bike that I have used this method, the cam chain sprocket did not have an "R" or "L" marking. The sprocket simply has an arrow on it. Rotate the motor until the arrow is horizontal pointing outward and you're there.

 

[edheiser]

Thanks again everyone

I just got back from the BMW dealer with my cache of new parts including a tube of special sealant "Drei Bond" I speak a little German and told them that means "Three Bond" which is 3 bond found lots of places, just got a blank stare back. Very nice people, took the whole staff to find the right piston for the new 15 mm head tensioner The tech came in and tried to answer my questions about reassembling the valve train. Couldn't remember a lot. The left lower tensioner blade came out with just the outer bolt removed, the diagram shows it secured by a pin and circlip in the center of the engine Either mine was never attached properly, or the diagram is drawn backwards, wouldn't be the first wrong drawing I've seen. Nothing to do but reassemble it that way.
Thanks rxcrider, nice diagrams of the 1100. I'll try again in the morning.

 

[edheiser]

no joy yet

I got the engine reassembled with a new head gasket and updated 15 mm tensioner. I left off the intake and exhaust for now, hooked up the battery, sprayed starter fluid in the intake side, and......nothing, no backfire fart or peep. I did a compression test, none. I did a leak down test, held fine. Has spark.
I did have a hard time getting the OT to show in the window, it turns evenly until it's almost in the window, then is very hard to turn, and when it moves, it goes way past the OT mark. Hopefully this all will mean something to someone, because I'm not getting it. I'm back to square one.

 

[20774]

Being hard to turn as you approach OT and then shooting past would seem correct. You're building pressure on the compression stroke with both valves closed. Then as you move past OT, the exhaust valve opens allowing the exhausting process to begin. Remove the spark plug and the build up of compression will be gone.

Sure sounds like you have compression. You provided the fuel. No fire. Sounds like something's wrong with the ignition and/or timing.

 

[pglaves]

You MUST turn the engine clockwise facing the engine from the fron until the top dead center mark is centered in the timing hole. Then look to see whether the camshaft sprockets are as shown in the repair manual for TDC. If they are you have confirmed that the cam timing is OK. If not, then not.

To prevent the hard turning followed by a spurt just take out the spark plugs.

Once cam timing is off the list (or not) you can proceed with further diagnostics.

 

[edheiser]

spark plugs are out!

You MUST turn the engine clockwise facing the engine from the fron until the top dead center mark is centered in the timing hole. Then look to see whether the camshaft sprockets are as shown in the repair manual for TDC. If they are you have confirmed that the cam timing is OK. If not, then not.

To prevent the hard turning followed by a spurt just take out the spark plugs.

Once cam timing is off the list (or not) you can proceed with further diagnostics.

What I described that was happening now IS with the spark plugs out!
Since I can't get it to stay exactly at OT in the window, I reassembled the left cylinder and installed the cam chain sprocket with the piston at it's highest level confirmed with the head off. The indent on the cam was not quite straight up, more like 10 or 11 o'clock, but the sprocket never left the chain, I zip tied it.
so perhaps it is off some. So my cam timing is off apparently. What would you suggest next.

 

[rxcrider]

One side has yet to be disassembled, right? What does that cam sprocket indicate with the pistons at TDC? When the pistons are at TDC, does OT on the flywheel show in the timing hole?

 

[pglaves]

One side has yet to be disassembled, right? What does that cam sprocket indicate with the pistons at TDC? When the pistons are at TDC, does OT on the flywheel show in the timing hole?

Unless the flywheel has been removed and replaced OT will be in the window at TDC because the OT mark is on the flywheel. But there are three cam chains. So if the crank is at OT then the cam sprocket arrow should be horizontal (or almost horizontal since some were marked a hair off). Check the undisturbed side.

And, if the plugs are out and you are still getting that "spurt" past OT it has to be the valve springs operating against the cam, thus pulling on the chains that are turning the engine.

 

[rxcrider]

Given that it is an RTP with over 100,000 miles, I figure it is a pretty good chance that someone has been into the clutch or before. I've already seen one bike with the flywheel installed wrong so OT & TDC weren't in sync. They managed to press the alignment pin back into the flywheel. It is easy & worth knowing if it is wrong since OT appears to be aligning with the peak of a cam lobe instead of overlap.

 

[edheiser]

Unless the flywheel has been removed and replaced OT will be in the window at TDC because the OT mark is on the flywheel. But there are three cam chains. So if the crank is at OT then the cam sprocket arrow should be horizontal (or almost horizontal since some were marked a hair off). Check the undisturbed side.

And, if the plugs are out and you are still getting that "spurt" past OT it has to be the valve springs operating against the cam, thus pulling on the chains that are turning the engine.

That's what it feels like, it's like the valve spring must be working against the chain, so what does that mean, and now what?

 

[rxcrider]

It means you need to slowly work through it to see where things have gone wrong.

Take the pistons to TDC - can be found within a few degrees by feeling the piston position with a screwdriver through the spark plug hole against the top of the piston.

Does OT show in the timing window?

Is the cam sprocket you didn't touch aligned with TDC or 180 off on overlap? If not, how much is it off by and does it look to be out by the same amount and direction as the one you worked on?

 

[pglaves]

Not to add confusion but it is time to mention the ability to use a pin to lock the flywheel at what is supposed to be tDC. There is a hole for this purpose above the starter on the left side of the engine. BMW has a special tool. A long 6mm Allen wrench works well. Insert from the rear through the aligning hole in the flywheel.

Then verify the pistons at least seem to be at TDC.

Then examine the cam sprocket(s).

I wouldn't even attempt to remove a cam sprocket without the flywheel locked in position. There is too much chance to mess things up.

 

[edheiser]

Not to add confusion but it is time to mention the ability to use a pin to lock the flywheel at what is supposed to be tDC. There is a hole for this purpose above the starter on the left side of the engine. BMW has a special tool. A long 6mm Allen wrench works well. Insert from the rear through the aligning hole in the flywheel.

Then verify the pistons at least seem to be at TDC.

Then examine the cam sprocket(s).

I wouldn't even attempt to remove a cam sprocket without the flywheel locked in position. There is too much chance to mess things up.

I was able to locate the aligning hole and lock in place today before I reinstalled the head. I had a choice to leave the sprocket on the chain in the same position I zip tied it or move it, I chose to keep it in it's original place. The head was at it's top, but I couldn't see OT in the window. It's either too low, or springs past.

 

[edheiser]

Hmmm

It means you need to slowly work through it to see where things have gone wrong.

Take the pistons to TDC - can be found within a few degrees by feeling the piston position with a screwdriver through the spark plug hole against the top of the piston.

Does OT show in the timing window?

Is the cam sprocket you didn't touch aligned with TDC or 180 off on overlap? If not, how much is it off by and does it look to be out by the same amount and direction as the one you worked on?

I don't know, I'll look in the morning.