Vintage BMW Motorcycle Owners

1968 69S. I thought I'd polish up the exhaust system over the holiday. It's in very good shape - no rust, some bluing, etc.

Got the right muffler off. Left muffler is stuck. Liquid wrench on all the joints. Heat. No joy. Both crossover joints seem to be moving a little. I thought if I could get the crossover apart, I could get the headers out - with or without the mufflers attached.

I can't really tell if moving the crossover joints away from each other (tapping the t-connections with a block of wood and a hammer) will work. Will the headers rotate outwards enough for me to separate the crossover?

This is far more stuck than it looks or I thought it would be.

I think time would be on your side...liquid wrench might be OK, but I prefer AeroKroil. On the upper end of penetrants is a 50-50 mix of ATF and acetone.

You might have some binding from the header. But be careful if you plan to loosen the exhaust star nut. The threads on the exhaust spigot galls easily. I don't do it, but these nuts are supposed to be loosened each year and new anti seize applied. If you could get the header pipe loosened, it would be one less thing restricting movement.

Thanks for the Aerokroil tip - I'll see if my local Napa store has some on Monday.

Yes, exhaust nuts are off which is why I was wondering if they can be rotated outwards as I loosen up the crossover.

Follow up on removing the exhaust -

Right muffler came off in 5 minutes. Left muffler took 2.5 hours of spray, heat, wiggling, jiggling and cussing.

Crossover pipe would not budge no matter what I did. It's location under the motor makes getting to it far more difficult and makes tool and method choices limited.

I decided to cut the crossover pipe off because the exhaust system is not original and a replacement crossover pipe is $33 at vintagebmwparts.com. Seems drastic, but laying on the floor banging on the crossover pipe for who knows how much longer made less sense to me.

While waiting for the crossover to arrive, I fired up my buffing wheel and cleaned up the headers. Well worth the effort. Pic shows buffed area to left and stained area on right.

Just my .02, leave the exhaust on. Its going to be blue/black in a few thousand miles anyway. but there ya go. There is some stuff called Autosol Bluing Remover for motorcycles made in Germany so it says. Have some but not tried in the 2 yrs I have had it. Those crossover pipes will be the least of your problem if you bugger the heads. Sounds like a lot of fun anyway.

I've tried all of those bluing "removers" on many bikes in the past and none of them really work, as far as I'm concerned. 20 minutes of rubbing to take bluing off 2 square inches - no thanks. It's why I took the exhaust off in the first place - I knew the headers would clean up on the buffer.

How exactly would I "bugger the heads" taking off the header? The headers were going nowhere with the crossover frozen on there.

I was referring to the spigot galling that Schrader was talking earlier. The threads on the exhaust where the pipe ends go in. Use some anti-seize on the threads before you screw the nut on. I use it on my spark plug threads and other stuff I don't need the threads messed up on.

Got it, thanks. Whoever put the exhaust nuts on the last time must have used some because they were the easiest part of that whole job to take off!

I guess I'm going to be forever "haunted" by removal of those exhaust nuts. Back in the early 1980s when I first got my /7, I decided I needed to change the rings...what the "f" did I know!! Before the internet, I didn't know what was at stake and ended up ruining the threads on one of the heads. I managed to get new ones made up by a guy in Austin...he did great work and the spigot has lasted 100K miles. Because of that experience, I never touched the exhaust nuts again...I had put anti seize on them before installation. When it came time to do my first top end, I didn't even try and turn them off...I went straight for the hacksaw and cut them off.

I did the same work on the R69S a number of years ago...I used the anti seize but I haven't touched the exhaust nuts just because of the remnant fear. If I don't have to, I won't. I understand it's good to do, but I don't have to!

Guess now I can tell my story. I bought a brand new Mazda RX3 with Rotary engine in 1973. In Fort Worth Tx. I was 25 in the USAF. The engine had 2 spark plugs per Rotor ( 4 plugs). Car had some 10,000 miles when I decided to check the spark plugs. One came out no problem. But the next,& next almost striped the hole out getting the plugs out. Since, I always put anti-seize on my spark plugs. One reason they last 50-80,000 miles now (2) 99% of the heads are aluminum, car, truck, bikes.