Timing chain replacement-help needed

[motoleo]

Finally got my newly acquired 82 R65LS carbs cleaned and the bike started up fine and idled nicely. Once warmed up there is a metallic noise that seems to come from the front of the engine and quickly disappears when throttle is given.

The previous owner gave me a new timing chain, tensioner and arm with the bike. I'm assuming I need to replace the timing chain , etc.

I also had a friend come over who is an airhead owner (has 3) and owns an automotive repair shop to listen to the engine. He feels that it is the timing chain and components.


I did a few searches on this list as wella s other sites but haven't found any info on how to replace the timing chain and components. Any help would be appreciated

[Bob_Roller]

How many miles has the bike accumulated ?

[wilcom]

I did a few searches on this list as wella s other sites but haven't found any info on how to replace the timing chain and components

Here's more than you would ever want to know....................

http://www.bmwmotorcycletech.info/timingchain.htm

[motoleo]

How many miles has the bike accumulated ?

Not sure... the odometer says 42,000 but i believe it is more.

[motoleo]

I did a few searches on this list as wella s other sites but haven't found any info on how to replace the timing chain and components

Here's more than you would ever want to know....................

http://www.bmwmotorcycletech.info/timingchain.htm

yeah I found that one but was hoping for something with less verbage and more photos showing what to do

[wilcom]

hoping for something with less verbage and more photos showing what to do

try this one lots of pics( when you get to the site you will have to go down quite a ways to get to the chain write up

http://brook.reams.me/bmw-motorcyle-rebuilds/1975-r756-build-s-replica/11-bmw-r756-replace-timing-chain-crankshaft-sprocket-nose-bearing/

[montmil]

Check in the forum's Photo Gallery where I have a photo essay posting on the R65 timing chain replacement.

You'll need considerably more than the parts you've listed: "timing chain, tensioner and arm".

Timing Chain, Fixed Slipper Rail, Tensioner, Spring, Circlip, 2-Cover Oil Seals, 3-Cover Gaskets. There are a couple tips that will save you mucho angst so sing out when you're ready to begin the process.

In the meantime, check out the Gallery.

Motobins Kit #10160 for R45/R65 shows all you'll need.
https://www.motobins.co.uk/bmw-parts.php?model=R%20Series%202%20valve%20Twin&bikeref=R90-6

[Luca]

If a picture is worth a thousand words, Snowbum will still have you beat, Monte!

In all seriousness, Monte's photo series is an excellent reference.  Between that and the links posted above you should be able to get where you need to go.  It also might help to buy a case of beer for your friend with 3 airheads in exchange for his assistance.  Just make sure you don't "pay" him up front before the work is done  

[montmil]

If a picture is worth a thousand words, Snowbum will still have you beat, Monte!

In all seriousness, Monte's photo series is an excellent reference.  Between that and the links posted above you should be able to get where you need to go.  It also might help to buy a case of beer for your friend with 3 airheads in exchange for his assistance.  Just make sure you don't "pay" him up front before the work is done  

Yes, Robert the Snowbum can be a bit long-winded but I love the guy and the time he spends on behalf of us Airheads. he did mentioned on a BMW Facebook page that he is attempting to revise his web site -less wordy and with less red n' yellow blocks. Bob says it's a major undertaking and will not happen quickly. I vote to leave it alone as it's still the best Airhead cure for insomnia.

Re: Timing chain install. The most frequently missed parts that need to be replaced are the two, small donut paper washers. They keep the timing chest in a flat plane and prevent possible alignment, bearing and oil seal issues -so sayeth the Sage of the Sierras. If you don't have new ones on hand. snip a pair from the used chest gasket. Better than nothing.

[BPT]

And what is the difficulty level on this for the uninitiated?  I was told mine would need to be done a few thousand miles from now.  I've seen some how-to's online but can't decide if I should attempt it or not, at least not without some assistance.   On a scale of 1-10?  

[Bob_Roller]

I'd give this job a 6 rating, not hard but you can run up against issues, like the exhaust nuts seized onto the cylinder head, alternator rotor, not wanting to come off, previous owners foul -ups .
But beyond that, it's pretty straight forward .
Also not knowing your mechanical experience, hard to say in your case .

[BPT]

I thought about the mechanical experience part after I posted.  I'm reasonably intelligent, very good at reading explicit instructions.  But I'd have to have explicit ones for this as my BMW experience is next to none.  I drove air cooled VW's for a long time and did a lot of my own maintenance but it's been a while so it's not fresh anymore.  I also rode a shovelhead HD.  Did a bit of work on that but not sure how much I learned as it was so damned frustrating.........
My problem is that I have no airhead riding friends so I would be solo doing this, probably posting on here asking tons of questions.

[montmil]

And what is the difficulty level on this for the uninitiated?  I was told mine would need to be done a few thousand miles from now.  I've seen some how-to's online but can't decide if I should attempt it or not, at least not without some assistance.   On a scale of 1-10?  

My Triumph 900 Triple shop manual describes the level of difficulty by using five 'spanner' images. Brit bike hence the spanner usage:

1 - Easy for novice
2 - Fairly easy for beginner w/some experience
3 - Fairly difficult suitable for competent DIY mechanic
4 - Difficult suitable for experienced DIY mechanic
5 - Very difficult suitable for expert DIY or professional

I'd give the timing chain job 3 Spanners for doing just the chain and related bits. That's equal to Bob's "6" rating.

Note that the camshaft sprocket rotates at half speed to the crankshaft sprocket. If you need to replace a pointy crankshaft sprocket, the degree of difficulty ramps up to 4 spanners. With the estimated mileage on your bike, it's doubtful the cam sprocket will need replacement so you're back to 3 spanners.

After setting the engine at TDC with the cam sprocket's timing mark dimple at the 12 o'clock, strongly encourage you to paint white the six o'clock tooth on the crank sprocket. Yes, there is a tiny scratch timing mark on the crank sprocket but it is hidden by the bearing.
   I failed to do this at the front end of my chain job and believe you me, is was a royally nervous PITA to confirm proper gear timing on the back end of the job. 180 degrees out of synch can be destructive. One tooth off will mess up ignition timing and require disassembly. Don't be that guy.

Buy a proper, hardened rotor removal tool. You'll need it.

Be sure to remove the ground cable from the battery as you'll be mucking about the diode board which has an exposed terminal that is always hot. Don't be that guy either.

Now that your anxiety level is at, what, 6 outta 10? Relax. It's not brain surgery and if you have a question, just stop and post your concern. If we don't know the answer, we'll make something up. What could possibly go wrong
 

[Tony Smith]

To which I would add a new outrigger bearing and a good three jaw puller to remove the old one.

This bearing runs in a oil mist and carries no load in the normal sense.  which means that theoretically it will have an inordinately long life.


But, [there is always a "but"] extended slow running or idling sees them run dry, they are subject to a certain amount of inevitable misalignment. and they are relatively cheap and relatively easily replaced.


What is VERY important if (like me) you buy your bearings at a bearing supply house rather than pay the OEM or after-marker parts supplier premium, be very sure that you and the supplier know that you need a GRADE "C " bearing and why. Unless you live in a large city it is unlikely that they will have a bearing in that size on the shelf (it is an odd size) and if they do I'm betting that it will be a grade "A" and that the supplier will suggest that it will make no difference.


In 999 out of 1,000 he/she will be right. If your luck is like mine - you will be the "1".

The Grade "C" bearing is specified not because BMW had a sudden corporate change of heart and wanted to specify a potentially cheaper bearing (they are in fact no cheaper and will probably cost extra due to having to be flown in) but because a Grade "C" bearing is designed with more internal "space" and is therefore able to tolerate slight misalignment without damage to itself and, more importantly, without damaging the bits it is mounted on through being unyielding to radial misalignment.

Consider the unloved outrigger bearing - It is a slip fit on the overhung nose extension of the crankshaft. outboard of it is a large lump of relatively difficult to balance soft iron and wire and is inserted into a non-adjustable, non-precision "mount" on assembly.

[motoleo]

Finally got my newly acquired 82 R65LS carbs cleaned and the bike started up fine and idled nicely. Once warmed up there is a metallic noise that seems to come from the front of the engine and quickly disappears when throttle is given.

The previous owner gave me a new timing chain, tensioner and arm with the bike. I'm assuming I need to replace the timing chain , etc.

I also had a friend come over who is an airhead owner (has 3) and owns an automotive repair shop to listen to the engine. He feels that it is the timing chain and components.


I did a few searches on this list as wella s other sites but haven't found any info on how to replace the timing chain and components. Any help would be appreciated

Got my R65LS safety inspected for Pennsylvania today so it is legal to ride on the streets. Took it out for a 15 mile ride and it seems to run very nice. Came back and checked the "S" mark on the flywheel with a timing light and the mark is right on and does not jump around so now I'm not 100% sure that it is a timing chain. I have 2 other questions concerning same noise on this bike...

1. Let's say it is a timing chain/ tensioner. What damage is possible if I leave the timing chain alone and use the bike over the spring and summer and wait till next fall and cold weather to replace the timing chain? I have several other bikes to ride and will not be putting many miles on the R65LS, perhaps 500-600 miles if that

2. If not the timing chain what else might the noise be? What else might I be at risk at damaging if I continue to use the bike.