Toaster deal fell through but i did buy a airhead

[bluecycle3]

Thanks for all the advice about the toaster, the bad news is the seller backed out of our so called deal so i had to move on.

I did manage to pick up a 74 R90/6 very reasonable and have a few questions about it.

The bike has high mileage, 105k to be exact but it is in very good shape, p.o put 99k of the miles on it and claims to have only had to replace the tranny at 70k.

I plan to have a friend do a compression check but hope to get many more miles out of it. What are my realistic mileages that are normally associated with a bike of this vintage? 150k? 200k? etc.

Is there anything that i should replace as a preventitive measure?

Im looking to replace the grips as he had the horid foam ones on it, what are the most common grips that are used on this type of bike?



Thanks again Greg

[PeoriaMac]

105 K miles is high, but plenty of BMW's that age have more miles. It really depends on how the previous owner treated the bike. Frequent oil and filter changes, spline lubing, carb updates/fixes as necessary. Mine has about 150-K and I've yet to do a bore job, although rings have been replaced twice. I had a rear drive replaced fairly early because one tooth had chipped, and I didn't want to take the risk. Is the bike dual plugged? Was a change made to an electronic ignition? Oil leaks, weeps or seeps? Some would say a compression or leak-down test should not only tell how well the engine sealing is, but how far apart each cylinder is from the other in terms of pressure. As far as grips: put on what feels comfortable to you...

Mac

[Boxerkuh]

Many Airheads have more than 150K on them... I think a compression check will tell you a lot. After you find out the results, you will know what to expect. I have found that the BMW grips work the best for me. But grips are truely a matter of personal taste. Good luck :clap

[pmdave]

Rather than think of an airhead as a machine that runs perfectly for X,000 miles, it's best to think of them as an ongoing never-finished project. As long as parts are available, you can keep one running forever. I haven't had any problem yet getting almost everything I need. And there are even upgrades such as better charging systems, wheels, and saddles.

Even if a compression check shows low, so what? Yank off the heads, do the valves, and slap 'em back on again. Adjust those valves about twice as often as you'd think should be necessary. Clutch getting "notchy"? No big deal, pull the transmission, lube the splines, grease the throwout bearing, replace the clutch cable. Wheel bearings growling? Pop out the bearings, put in a new set with the correct shims, grease them copiously, and knock in new seals. Good as new.

On the other hand, if you're not mechanically inclined, you've got a tiger by the tail.

pmdave

[bluecycle3]

Thanks for the replies everyone, this is a great forum. Im about to put a new battery in the bike, what is the best way to get the old one out and put in the new one? I have done it several times over the years but it always seems like quite a job, do i pull the sub-frame? or do i pull the airbox covers to give me room to get it in and out? Thanks again greg

[pmdave]

Depends on the model, the battery dimensions, etc. On my '80 R100, I remove the nuts holding the battery box to the rubber thingies on the upper sides, then tilt the battery box back toward the fender a bit until the battery can be extracted out the top. The rubber connectors at the bottom of the box will take some abuse, but after the battery is removed I generally remove the box, check out the rubber isolators, and then scrub and repaint the box to keep the rust/corrosion in check before putting it back together.

One change I've done recently is to relocate the battery ground wire from the transmission vent bolt to the frame tab where the subframe attaches to the main frame. It's not so much a matter of a better ground, but a firmer connection. The vent bolt on the transmission tends to strip the aluminum threads, and that creates a number of additional problems.

When removing or replacing a battery, remember: always remove the ground wire (-) first, then the positive (+). When reconnecting, connect the positive first, then the negative. Mo betta no make big sparks. (OK, I'm reading Michener's Hawaii)

pmdave

[James.A]

pmdave is correct in that the rubber mounted battery box can be tilted back toward the fender. Another little trick is to loosen the top bolts (remove the nuts and washers) that hold the rear sub-frame and withdraw them partially until they are flush in their holes. That is to say "not protruding". This leaves enough room to pull/drop in a battery.