Valve adjustments interval

[Tbarcia]

Just back from a ride and noticed bike wasn't idleing right. Checked the vale clearences and they were all tight (gap was too small). After adjusting, the bike is running fine. I have put 5K on this 1984 R100RT since I bought it (mopstly high speed). I adjusted the valves when I bought it.
Is this usual wear or am I in for a surprise. I did read about some metal issues BMW had but I thought it was on earlier models

[RandyB]

5k sounds about right. That was about the interval on mine when I got it. Over time, the interval decreased.

I finally sent the heads to Memphis Motorwerks as part of the rebuild.

I'd keep track of the interval and when it gets bothersome, have the heads redone.

[DennisDarrow]

This is far from "normal". If you are positive on the previous settings then, to me you have problems. There are lots of threads about the metalurgy of the valves, the remedies, and what to watch for. Do a search of valve recession.........Good Luck.......Dennis

[crazydrummerdude]

This is far from "normal".

Really?

[20774]

...or am I in for a surprise. I did read about some metal issues BMW had but I thought it was on earlier models

Well, you shouldn't be surprised now. Yes, the '84 models were the last of the run of poor metallurgy for valve seats. Sounds like you've got valve face plastic deformation. The valve is deforming (losing clearance) because heat can't be transfered out of the seats to the heads properly resulting in the heat being dumped into the valve face.

My advice would be to now watch your valve clearances closely, say every 1000 miles. If you get similar closures in shorter and shorter periods of time, you're a candidate to have your heads updated. Not a big deal. Oak Okleshen sells a booklet for $25 that's worth having to guide you through the process...also change your pushrod tube seals at the same time. Find your favorite shop that know about Airhead engines and let them do the work (my suggestion rather than any run-of-the-mill engine shop.)

[shire2000]

Kurt has the right idea. I jsut consider it standard maintenance on any Airhead I do not know the history of. If valve clearances start to dimish in shorter and shorter times, then the valve job is due. I take the heads off myself and send them to a local shop I trust. Replace the pushrod tube seals if leaking or look old. Inspect for any other obvious issues. Put it all back together. After about 1000 miles adjust the valves as may be required, check it again at 5000, if all fine, then leave them be until they start either making too little or too much noise. They should make a bit. A happy boxer will "talk" to you.

:ca

[BMWRich58]

All the Old "Airhead Guru's" I've ever met (alive or gone), always told me "Airheads have a big need for TLC".
Valves like to be "tickled" every 3500 miles for that "Oh so sweet-smooth happy feeling".
Keeping the valves adjusted and them carb's in sync, will make or should I say keep any "Airhead Owner" happy!!! :twirl

[Polarbear]

I have a '78 R100 since new and its now at 340000. A lot of miles and I use my ORIGINAL valves still:). It did for years have some valve recession but I found a product at my auto parts store that nearly or totally stopped the valve recession. The bike still runs as strong as new, imo and I use the additive every tank. One Quart bottle,"CD2" a lead substitute can treat "40-50 tanks of gas" and I have a 9 gallon tank. I have rarely had to adjust my valves since I started using this stuff a few years ago. Just another thought, Randy:usa PS; It clearly says on the bottle, for "offroad" use only, BUT?

[RandyB]

While you're in there, check the compression. If you take the heads off, might as well know if it needs new rings. You could also balance the rods and pistons. I'd replace the pushrod seals unless they are brand new. Very little extra work.

Welcome to the madness.

[shire2000]

For the small amount of extra time, I check my valves every time I change my oil. That is around every 5000 miles, sometimes a little more and sometimes a little less. I pull the drain plug and while oil is draining, I check the valves. Not a big deal. I usually don't need to adjust them, maybe once every 5-10 oil changes, depending on the bike.

I just did an oil change on my 1981 R100RT, checked the valves and they were dead on. Last time actually had to adjust them was 28,000 miles ago. Has over 100,000 miles on it now. The 1978 R80 has only 75,000 miles on it and has gone 24,000 miles since last actual adjustment. Still check them every oil change. That one is due probably next month. The 1980 R45 still has the same adjustment since 1982. It is very low mileage (only 10,000 Km) and I expect will stay that way. It was off the road for 25 years and only just recently was taken out of moth balls. The 1978 R100 has 275,000 miles on it and still has the stock valves. Last time valves were adjusted was 48,000 miles ago. I check them and they still are sitting where they should be. Heck that bike still has the stock clutch. Just starting to slip so it will be replaced next month. I have had virtually no trouble from that bike since I got itover 20 years ago. I expect it will just give up the ghost one day, which will give me a good excuse to tear her down and rebuild from one end to the other. Or maybe just mount her on a pedestal in the family room.

Valve adjustment, once done properly is not a big deal. Sure, some valves will give problems over time, but that can happen on any set of valves. Some people seem to have more problems than others. Some people use additives, some don't. I have never bothered with any additives. I always seem to get pretty good mileage out of a set of stock valves. I don't baby my bikes, I ride them hard. They look it, but they keep coming back for more. Just give them normal maintenance, good quality oil and don't over abuse them in hot weather and you can lots get of miles out any airhead.

As to Airheads needing lots of TLC, don't believe it. They were made to be reliable and to be riden hard. Do regular normal maintenance, give them a good warm place to sleep and they will always get you where you want to go and back.

:ca

[boxermaf]

+1.. or +2, or +3 to the above - 5K miles IF the valves were properly adjusted to begin with, is pretty quick for the clearance to close up by more than approx .001" or so. I would keep an eye on it each 1000 miles as suggested and see if you observe it closing up as fast or faster... maybe the first time was just a fluke and they weren't set where you thought they were initially. If they are closing up in 1000 mile intervals then you'd better plan on pulling the heads and sending them in sometime this year. But, after that, you'll probably be good for the next 100K miles with just slight adjustments ever 5K or 10K miles, if even, after the initial adjustment/torque of the heads, etc.

[ccolwell]

My '84 R100 needed the exhaust valves done about every 1800 mi. before I had the valve seats replaced.

[26667]

I thought every 5000 mi was the recommended interval btw factory services, alternating the major and minor service regime. The valve adjust is included in both. But you say your valves had closed. All four? Inlets too? One would expect the exhaust valves to close up a bit, for reasons involving metalurgy etc mentioned above, but if the inlets are closing up as well, I wonder if your problem might also include not torqing the lock nuts properly.