Tuesday, February 8, 2011

Valve Recession Update

Just got a call from Ted at the Beemershop and he confirmed my initial diagnosis. My airhead was suffering from a bad case of exhaust valve recession. From what I've read, this is caused by a change in the metallurgy of the valve seats that BMW made in 1980 due to the unavailability of leaded gas. This resulted in poor heat transfer between the valves and the heads. Valves, seats, springs and guides will be replaced as well as machine work on the head to ensure that the valve seats fit well. Estimated time to completion is about a week and a half. I may get the heads back on the bike before the end of the month in exchange for a lightening of my wallet. And they will be shipping all the gaskets and O-rings to get it back together. I think I will put off the ugrade to the charging system until next year. BTW, I should add that all of my interactions with the Beemershop have been great. I've ordered stuff from them many times in the past and when I shipped the heads, I said "no rush".

I don't think that I ever got used to the time change last week from traveling to the east coast. Combine that with the stress of teaching a workshop that I haven't done in over a year. I ended up arriving home completely exhausted and just wanted to sleep.


  1. I was thinking about the things I'd like to do motorcycle wise in 2011 and was feeling my wallet getting lighter by me just thinking about it. I'm sure you we'll be pleased.

    I don't fly anymore because I just can't adjust gracefully to time changes that quickly anymore. Add having to do the workshop and I can only imagine how exhausted you must feel.

    Take care,

  2. Keith:
    Feeling better today but need to go north in a couple of days. At least there is no time change. I just need to make myself stop working at the end of the day.

    Thank you for stopping by and the good wishes.


  3. Good news about getting your heads back soon but sorry about the lightened wallet. It would be nice if it were covered by some sort of warranty. :)

    You travel quite a bit. That can be fun but also tiring. Take care - Mike

  4. Great news about the possibility of getting the bike back together soon! Remember to polish all shiny parts before reassembly. As many times they can't be reached once whole. :)

    Time zone change? Bah! My old boss got around that by "working as usual". (He was rather tight fisted, though.)

    Do you think the sleepy and exhaustion could have anything to do with the short hours of sunlight? ;)


  5. Mike:
    Yes it would have been nice if there was some sort of recall. Apparently, there was simply a change made in the '85 model year which eliminated the issue but there was never an acknowledgment from BMW that a problem ever existed. (Kind of sounds like the final drive failures you hear about on the Internet)

    No, I think the exhaustion came from working late every evening reviewing the material and probably too much coffee. Normally the time zone change doesn't bother me much. And I don't think my old bike has too many shiny parts.


  6. I have noticed the tendency of wallets to lighten when motorbikes join the household. The Beemers are reputed to be especially talented in this endeavor.

    Glad the bike will soon be good as new. Go rest!

  7. Richard

    there's really not much that's cheap when related to a Beemer is there?


    Colorado Motorcycle Travel Examiner

    Redleg's Rides

  8. Dom & Kari:
    How does the saying go... "The only thing cheap on a BMW is the owner"

  9. RichardM:

    the good thing is that you are going to have a nearly new engine soon.

    I think the Government probably mandated that gas contain no lead so it took a few years for manufacturers to make the change. I think now with the use of Ethanol it is going to create other problems with small engines. High sulphur content also damages fuel systems.

    Wet Coast Scootin

  10. Bob:
    It wasn't that it took them a couple years to make a change to work with unleaded fuel, but they made the wrong change then changed again later. The 1980-1984 1000cc models are the only ones with the problem.

    Ethanol dries out rubber parts faster. There are some carb diaphrams that I should take a look ak someday.