Cylinder heads and Chain rail guides

Curious question and I am hoping that it will garner a few opinions, How important are the Chain rail guides?

I ask as that I am in the process of replacing the cylinder heads on my r 1150 rt after having snapped several bolts while taking off the exhaust manifold (bike has 103K miles on it), after snapping two torx bits and bending another two, finally got the heat gun out and got the bolt on the sprocket off. However, upon taking the cylinder head off I found that both the upper and lower chain rail guides for the chain are fried (closest whole piece looks to be back about 4 inches from the pin). I fully expect the left side to be in the same condition and have ordered new ones. I did not use an impact wrench/ drill to take these off so I don't believe that I broke these in the process of taking them off.

How might these affect fuel mileage and the operation of the bike? I know they assist in the timing of the engine and I ask because I have been fighting with the bike to get the mileage back close to what I once got- 54 mpg (while doing 75 MPH) back in Colorado at about 6500 ft (bike only have 60K miles at the time). Ever since then though it has dipped as low as 38 MPG and is currently averaging in the 40-42 with an average speed of about 50 (live in SE PA so lots of country roads and 50 is about as high as you want to go due to amish carts and deer).

Also, while I have the pistons off (currently cleaning them as well) is there anything else I should be looking at upgrading/ fixing as I don't intend to take the engine apart again for a while after this. I have already ordered the new cam chain tensioner for the left side as I found it to be the original stock tensioner when I started this project (not that it matters if the rail guides are fried on that side as well).

Curious question and I am hoping that it will garner a few opinions, How important are the Chain rail guides?

 

I ask as that I am in the process of replacing the cylinder heads on my r 1150 rt after having snapped several bolts while taking off the exhaust manifold (bike has 103K miles on it), after snapping two torx bits and bending another two, finally got the heat gun out and got the bolt on the sprocket off. However, upon taking the cylinder head off I found that both the upper and lower chain rail guides for the chain are fried (closest whole piece looks to be back about 4 inches from the pin). I fully expect the left side to be in the same condition and have ordered new ones. I did not use an impact wrench/ drill to take these off so I don't believe that I broke these in the process of taking them off.

How might these affect fuel mileage and the operation of the bike? I know they assist in the timing of the engine and I ask because I have been fighting with the bike to get the mileage back close to what I once got- 54 mpg (while doing 75 MPH) back in Colorado at about 6500 ft (bike only have 60K miles at the time). Ever since then though it has dipped as low as 38 MPG and is currently averaging in the 40-42 with an average speed of about 50 (live in SE PA so lots of country roads and 50 is about as high as you want to go due to amish carts and deer).

 

Also, while I have the pistons off (currently cleaning them as well) is there anything else I should be looking at upgrading/ fixing as I don't intend to take the engine apart again for a while after this. I have already ordered the new cam chain tensioner for the left side as I found it to be the original stock tensioner when I started this project (not that it matters if the rail guides are fried on that side as well).

Afternoon jelake

Those cam chain guides are very important to chain tracking, chain life, & proper engine function. (basically you do not want to try to run the engine without them at least mostly intact)

At your current engine mileage, & the requirement to remove the engine & disassemble for proper chain guide replacement, plus the very high cost of BMW engine parts my advise is to just buy a good used BMW 1150 engine with less miles & intact cam chain rails.

Those cam chain guides are very important to chain tracking, chain life, & proper engine function. (basically you do not want to try to run the engine without them at least mostly intact)

 

At your current engine mileage, & the requirement to remove the engine & disassemble for proper chain guide replacement, plus the very high cost of BMW engine parts my advise is to just buy a good used BMW 1150 engine with less miles & intact cam chain rails.

 

+1 to all that has been said here.

Definitely appreciate the reply, I figured it was fairly important- problem I have is that I honestly have no idea how long they have been broken since I haven't noticed any definitive changes in engine noise for a very long time (have owned it since 2012 at 58K). However, I currently have both replacement cylinder heads in the garage, the replacement chain tensioner is enroute as well as the new rail guides (all 4). At this point, I am going to go ahead with the repairs as that I am already 50% of the way there lol. Thus far the engine and bike have bene good to me and with a bit of TLC I don't see why that wont continue. I do plan on upgrading once I can fit it into the budget. Have been looking at 1200rt's (post 2010), K1300 gt's, or bumping up to the 1600 gt- but as of right now all of that is just window shopping.

Update, finally got the 12mm allen wrench in to start removal of the final drive, driveshaft and transmission to do the rail guides. However, on pulling the outside pivot pin on the final drive, i found two small pins laying in the housing. Any ideas as to what they might belong to and how much deeper this repair just became?

Upon further reflection and inspection, looks like the pins are coming out of a bearing of some sort that the pivot pin inserted into...

If you are doing all that disassembly just to replace the cam chain guides, STOP. It can be done with the engine in the bike. Directions are out there on the 'net.

My dad did this repair on an early R1100RS bike he bought for parts. After getting it home, and communicating with the former owner to verify that he sold it for parts rather than take out the engine to replace the guide, he decided to repair it rather than simply use the parts. I remembered seeing a post about that repair, which involves making a very simple tool to break off a piece of aluminum casting flash which is in the way. Then the guide can be replaced without engine split.

The bike ran many thousands of miles before he sold it after finding a low mileage late R1100RS.

Problem is i already have it most of the way apart. I am aware of several other ways yo do this rather than splitting the engine. The method i intend to employ is taking the transmission off to get to the back of the fly wheel which will then allow access to pop the pins that hold on the guides without splitting the engine.

If "all goes well" then i should have it all back together in a week or two, depending on my military and family obligations. This also allows me to find items that are in need of replacing such as the needle bearings which i will be replacing with the upgrade kit from rubber chicken.

Problem is i already have it most of the way apart. I am aware of several other ways yo do this rather than splitting the engine. The method i intend to employ is taking the transmission off to get to the back of the fly wheel which will then allow access to pop the pins that hold on the guides without splitting the engine.

If "all goes well" then i should have it all back together in a week or two, depending on my military and family obligations. This also allows me to find items that are in need of replacing such as the needle bearings which i will be replacing with the upgrade kit from rubber chicken.

Afternoon jelake

I think that you will find the pin under the flywheel will be stuck pretty darn tight as most won't drive through easily. That pin is pinched between the very tightly torqued crankcase half's. Most of the online videos showing how easy it is are done on hollow crankcases that are loosely put back together.

As far as fuel millage is concerned. being in Colorado 6.5K alt. I would say that the thin air or lack of compared to sea level has a play in your millage. The higher the Altitude, less air and less fuel mean better gas millage. Just the opposite at sea level. Fuel injected only

Your fuel millage at sea level or close to it is right as far as I am concerned. . .

Dirtrider, thank you for the advice. The only other method I am aware of is the slotting method which I am skeptical about. Doesn't seem quite right to cut holes in something that is supposed to have tension/ pressure on it maintained at all times in order for the engine to run correctly. Definitely open to ideas on anything that might be easier and still reliable, or at least proven reliable- I have read about the slotting method but no one ever rights about it after they have supposedly tried it? lol.

As for the rest of things, have ordered the upgrade kit from rubber chicken for the final drive pivot pin bearings, should be in by thurs or fri since I received the shipping notification. Looked at the one bearing that the pins had come out of and looks like 3/4s of them are missing so I am inclined to think that some if not all of the missing ones found their way inside the FD meaning one more thing to take apart. This project def feels like pandoras box at this point as the more I take apart the more I keep finding. Granted, its one of those you either fix it now as you find it or pray it holds and wait for the catastrophic fail later. Also doesn't help that the previous owner apparently didn't pay attention to any of the BMW bulletins for part replacement/ upgrade during the 1st 8 years of the bikes life.

... I ask because I have been fighting with the bike to get the mileage back close to what I once got- 54 mpg (while doing 75 MPH) back in Colorado at about 6500 ft (bike only have 60K miles at the time). Ever since then though it has dipped as low as 38 MPG and is currently averaging in the 40-42 with an average speed of about 50 .

Are we talking about UK or US Gallons?

If you are talking about US gallons and you got 54mpg at 75MPH, I can tell you now, that figure is screwy and slewed. The only way you would get that is with a ferocious tail wind and/or your point of top up and calculation was out. The other figures you talk of are much more in keeping with this bike.

In the UK, my average over 130000 miles is 52.5mpg and yes, I too have had the odd trips into 60mpg, but only under those strange climatic conditions and is certainly NOT the norm. You are searching for the unattainable.

Dirtrider, thank you for the advice. The only other method I am aware of is the slotting method which I am skeptical about. Doesn't seem quite right to cut holes in something that is supposed to have tension/ pressure on it maintained at all times in order for the engine to run correctly. Definitely open to ideas on anything that might be easier and still reliable, or at least proven reliable- I have read about the slotting method but no one ever rights about it after they have supposedly tried it? lol.

 

As for the rest of things, have ordered the upgrade kit from rubber chicken for the final drive pivot pin bearings, should be in by thurs or fri since I received the shipping notification. Looked at the one bearing that the pins had come out of and looks like 3/4s of them are missing so I am inclined to think that some if not all of the missing ones found their way inside the FD meaning one more thing to take apart. This project def feels like pandoras box at this point as the more I take apart the more I keep finding. Granted, its one of those you either fix it now as you find it or pray it holds and wait for the catastrophic fail later. Also doesn't help that the previous owner apparently didn't pay attention to any of the BMW bulletins for part replacement/ upgrade during the 1st 8 years of the bikes life.

Morning jelake

I do know of a couple of riders that have cut slots in the lower guide rail pin slots. In both cases the engine started & ran OK after that type of rail replacement. As far as I know they both lasted for a while as neither engine failed shortly thereafter. The big issue in doing it this way is making DARN SURE that you get ALL the broken bits & pieces removed from the crankcase that occur from cutting/chiseling/prying the old guides out.

The chain tension should hold the slotted rails in place, my only concern is the rail slots losing some of their structural integrity due to opening up the supporting loop. The fixed hole ends should keep the rails from moving or migrating & take most of chain thrust load.

But the 2 bikes that I am aware of were also traded or sold before many miles were put on them.

The other option is driving that rear pin out (after removing the circlip) without beating on it so hard that it breaks the thin seal between the crankcase halves in the pin area-- I have tried to drive a couple out of old scrap engines (just as a test) & my fear was that driving on that pin hard enough to drive that clamped pin out would force rear crankcase deflection & crankcase separation enough to have an oil leak in that area after re-assembly. I haven't actually ever tried to replace the lower chain guides that way myself due to the above mentioned fears (I have tried to drive a few pins out on scrap engines)

I really hate to remove & disassemble a boxer engine but I would hate even more having to re-assemble the engine with a half-ass repair & transmission re-install THEN have to remove the trans & engine again for a correct repair so my (personal thought) is to just do it correctly to begin with.

As a rule I just bite the bullet & disassemble the engine & do the rail install correctly, that also allows bearing inspection & chain wear investigation.

At higher miles like your engine has I probably wouldn't do a disassemble & repair as the cost is fairly high for the miles remaining. Used (lower mile) engines are not that difficult to find & cost-wise probably a better direction.

If I was working on your bike & pulling the transmission I would first evaluate the spline wear & if found then check the rear main bearing for lateral wear & crankshaft lateral movement. If that is found then definitely find a lower mileage engine.

Hi jelake - even the redoubtable Chris Harris says in his video on this topic that replacing smashed plastic cam chain guides is no joke.

Not a job for the faint-hearted. Best o' luck with the work !

AndyS,

You are correct on the 54 as I just went back and redid the math and it was 51.4 (314/6.1). Yes, they were US Gallons and I always try to hand calculate my mileage i.e. miles recorded on the odometer/ amount put into the tank. As for unattainable, perhaps but it is a decent goal that I don't believe is completely out of sight, provided one has a bike in sound condition.

Dirtrider and Alan,

Again, thank you for the sage advice. I have watched Chris Harris video which is why I settled on that method in the first place, fully realizing the work ahead, although I wasn't expecting to be finding the other items that are wrong as I keep getting deeper into the engine.

As for the spline, that blew up on me around 68K miles, so the spline and the entire clutch were brand new as of then. Was a 1/4 miles from the house on a 65 miles commute to work when it happened so I got lucky. Not so happy to find the $4400 repair bill though. Since then I have tried to do whatever work possible myself, as long as it is within reason.

I have read through this forums pages, so far I have made it to 2011, and haven't found too many articles on the chain rail guides (lots on the left side tensioner), and most referred to the slotting method. The Harris method I actually stumbled on when I was looking at his videos on removing the cylinder heads. Pulled the FD and driveshaft this weekend so the starter and trans is all that is left with the flywheel before I have access to the pins. I keep joking with my friends that at this rate by the time I am done the bike will have essentially gone through a full rebuild as newer items keep finding their way into it to replace the broken ones. Main problem at this point is with the time it is taking will be remembering exactly which bolt goes where, good thing they are all separated according to where they came out.

Hoping to have her back together by mid to end april in order to put the truck away for the warmer months and use the bike for my commute instead. If anyone lives in the SE PA area, if you want to lend a hand I will be more than happy to buy a six pack in return.

So small update, personal log- stardate 20180302, at this point project pandora's box is now ready for me to pop the pins holding the chain rail guides in place. However, as has been the tendency thus far, upon removing the cylinder jugs and inspecting the piston heads after having already de-carboned the faces, significant carbon buildup was found both in the grooves for the rings and behind where the rings sit on the piston. As a result, called the dealer today and verified a few details i.e. cost of new rings for both sides will be in the area of 260 prior to tax and the jugs will need to be honed- or option two, new pistons which would include the rings and wrist pin for 458 a piece, so basically $1000 and the cylinders would still need to be honed.

At this point I am already in the bike for more than it is worth, both in labor and in parts. Although I fully intend to finish the job and put it back together (after what amounts in my mind at this point as a near engine rebuild, sure I might have overlooked something but there cant be much else that needs to be done besides sandblast) I have the decision to make of do I keep said bike and run it for another 60k or more, or do I go ahead and pull the trigger on another bike?

About the only way I would make money selling it is via private party as I don't see a dealership giving me anything north of 1500 (if that) for a 14 yr old bike with 102K on it; however, as the saying goes, it is the devil I know (and quite thoroughly at this point) versus the devil I don't know i.e. a new bike.

Thoughts anyone?

So small update, personal log- stardate 20180302, at this point project pandora's box is now ready for me to pop the pins holding the chain rail guides in place. However, as has been the tendency thus far, upon removing the cylinder jugs and inspecting the piston heads after having already de-carboned the faces, significant carbon buildup was found both in the grooves for the rings and behind where the rings sit on the piston. As a result, called the dealer today and verified a few details i.e. cost of new rings for both sides will be in the area of 260 prior to tax and the jugs will need to be honed- or option two, new pistons which would include the rings and wrist pin for 458 a piece, so basically $1000 and the cylinders would still need to be honed.

 

At this point I am already in the bike for more than it is worth, both in labor and in parts. Although I fully intend to finish the job and put it back together (after what amounts in my mind at this point as a near engine rebuild, sure I might have overlooked something but there cant be much else that needs to be done besides sandblast) I have the decision to make of do I keep said bike and run it for another 60k or more, or do I go ahead and pull the trigger on another bike?

 

About the only way I would make money selling it is via private party as I don't see a dealership giving me anything north of 1500 (if that) for a 14 yr old bike with 102K on it; however, as the saying goes, it is the devil I know (and quite thoroughly at this point) versus the devil I don't know i.e. a new bike.

 

Thoughts anyone?

First though would be to toss a good low mile used engine in it. Probably be way cheaper than buying piston rings & related parts & labor.

You still don't know how your bearings & crankshaft look (rings worn, crank journals worn egg shaped, chain guides shot, etc) what is to say the engine bearings & valve guides are in any better shape.

Personally, for me, it would be a good used engine but if I didn't go that route then with all it needs so far I would definitely remove the engine & disassemble then mike the crank journals for out-of round & do a quality valve grind (probably valve guides also). Might even find some wear on the front chain, guides, & tensioner.

Too bad you are in Pa. We are 3,000 miles away.

I have a perfectly good 1150 rt motor you can have for $100. 89k

But packing and crating cost too much and the valve covers & hall sensor are worth twice that!

I swore off 1150 RT's last year and now have 3 R1200RT's.

Mark

OMG jelake - what a quandary !

You've already - as you say - spent more hard-earned loot on the bike than its 2nd hand resale value.

As DR says so sagely:-  keep the motor unit as a spares item and flirt a good used motor into the bike. Then you have a handy source of replacement parts : - ign wiring, plugs, coils, injectors, alternator, starter motor, Hall Sensor, bearing seals, blah-blah. That's if you have enough storage space at your place.

Makes much more financial sense than flogging this particular dead horse. I bet BBY or The Bay in the USA can offer just what you need. And it allows you to follow this forum's golden rule - Don't spend time wrenching - spend more time RIDING !

AL in s.e. Spain

Have finally crested the point where reassembly is now in progress. Successfully drove the lower cam chain rail pin out with a 1/4 inch punch and 2.5lb sledge (bent the punch in the process). Picked up some permatex gasket sealer (grey- supposed to be able to withstand up to 700 deg) for the inner seal on the cylinder jug along with ordering new rings for the pistons. Hoping to have her back together by mid to late april and riding full time by late april or early may.