Noise in front of engine at idle

[cwmoss]

I am new to BMW's, always thought were cool, but finally jumped in with a project bike, a 79 R65, with less than 40k miles on it. I bought it without hearing it run. It was in storage for the winter and had a flat rear tire and needed a battery. Brought it home, got tires, tubes and a battery ordered. It needed the front forks gone thru, so I got all the pieces to rebuild them. As soon as the battery came in, I put fuel in the tank, checked that it had oil, and spun it over a bit, and it fired up. I noticed at idle the generator light comes on, but goes out as soon as it comes off idle. The valves sounded fine, so I shut it off and started doing the tires and forks. Got all of that done and today fired it up and took it for a short ride. Shifts fine, but now it seems to not run good at idle, stumbles some, but clears up at about 1200 rpm. When I get back to my shop, I hear what sound like a valve way out of adjustment at idle, but it's coming from the front of the engine, and goes away as soon as it comes off idle. Any idea of what I need to look for?? Here are a few pics of the bike, when bought and now.

[Barry]

The thing that usually makes a noise at the front of the engine is the timing chain.  You can get some idea of what state the chain is in by observing the ignition timing marks with a strobe. If the image is jumping around as alternate cylinders fire that's an indication of wear/slack in the timing chain.

[montmil]

Checking oil level before your first ride was a good idea. Now that you know your new R65 runs, it's time to change all fluids: engine plus oil filter, transmission, drive shaft and final drive. Start a service record and log what and when you do your maintenance. Memories fade; ink, not so much.

Drop the float bowls and inspect 'em for water and any silty debris. You may need to run a couple tanks through the bike before thinking about a carb overhaul. If not already installed, an in-line fuel filter is good insurance. I use the small plastic w/filter elements sold at power equipment shops. All sorts of crud can collect in the R65 fuel tank. With only one petcock, the other side of the saddle tank can be problematic. A tank drain, rinse n' fluff dry would be good for your new/old bike.

A mechanic's stethoscope or a l-o-n-g screwdriver can help isolate noises. The timing chain, its guide shoe and a tensioner live in that black, finned case behind the alternator/stator cover. BTW, disconnect the battery's grond cable before removing the engine front cover. There are exposed "hot" terminals under there and although it is difficult, it's possible to contact a live terminal with the aluminum cover. This would be considered a "bad thing" for your electrical $ystem.

Suggest you purchase either or both the Clymer and Haynes service manuals. Sure beats reading People magazine.

You'll enjoy the sporty R65. Ask questions before digging too deeply. Most of us have a vast storage vault full of errors and experience that we can assist you with; both in avoiding and enjoying.

Are you missing the R65 side covers and instrument cowling?

[cwmoss]

Thanks guys. I have a Clymer manual. That and youtube videos helped me with the front fork overhaul. I have a new oil filter and will  be changing all fluids, along with doing quick tuneup, points, plugs and flushing the front brake. I have the side covers and front fender. I am gonna drop the fuel bowls and see what they look like, but am gonna get some kits for the carbs coming. I am also gonna get some gaskets for the valve covers, pan and the front timing chain cover. I am gonna take a peek in there. I did notice when I took it for the short ride, that the  stop light was always on. I ran it down to the switch on the front brake, unplug one wire and the stop lamp goes out. I still have the rear brake to turn the stop light on for now.

[montmil]

The R65 is notorious for losing their side covers; particularly the right side as the left one can be captured by the lift handle. Run a small zip tie twix a couple of the louver vents and run in around the nearby frame member. No need to over-tighten the zip as it may crack the cast resin panel. Just enough to keep it from falling off and getting crushed by that Class A rig back behind you.

Timing chain case gaskets should include the two small, individual round gaskets that fit up top and between the chain case and engine block. They don't control oil but they are needed as shims to assist in the even torque down of the case-to-block joint. Often missed and/or overlooked.

You may as well replace the oil seal, too.