Results 1 to 7 of 7

Thread: '76 R90/6 cold start problems

  1. #1
    Registered User
    Join Date
    Aug 2011
    Location
    Arlington, TX
    Posts
    15

    '76 R90/6 cold start problems

    Hi all,

    I was about to post a question related to my difficulty starting the R90/6 cold. Well, I was playing around with spark and gas issues. Yesterday I decided to check my valve clearance. I was sure the right side wasn't right. I pulled the valve covers and lo a behold the left side was too tight. I set the clearance to .006" intake and .008" exhaust. At this point the bike was still a little warm but it seemed to run better. Just to make sure it was running better I took it for a 150 mile run.

    This morning, with the garage temp about 60 degrees, I set full choke and tried it. It started right up. Yippee!

    I think I nailed the problem and I'm no mechanic. I love this bike!!!

    Brian
    1976 R90/6
    Member# 174498

  2. #2
    Macrunch MCrenshaw's Avatar
    Join Date
    Mar 2008
    Location
    Bedford, TX
    Posts
    79
    Congratulations Brian. The R90/6 is a solid reliable bike. Now that you have the valves adjusted try a carb sync and you'll really be delighted. Quite a few airheads still around in this area, maybe we'll meet up one of these days. -Mike

  3. #3
    Registered User festes's Avatar
    Join Date
    Aug 2006
    Location
    Waldorf, MD
    Posts
    37
    Congratulations on finding the cause of the cold start issue.

    Now, just keep an eye on those valves to see that they don't tighten up again. Some of the old airheads suffered from valve seat recession (sp?) meaning the valve would wear deeper into the valve seat, thus causing the gap at the adjustment point to tighten up.

    Mark

  4. #4
    Registered User lmo1131's Avatar
    Join Date
    Jan 2010
    Location
    Pismo Beach, CA
    Posts
    3,049
    I think I nailed the problem and I'm no mechanic.
    No... actually, you are! s

    Just like the old air-cooled VWs, these bikes thrive on correct valve clearances; and it's so hard to do, isn't it? As mentioned, a carb synch is the next order of bidness ... there's plenty of help here on the forums for learning how to do that.
    "It is what you discover, after you know it all, that counts." _ John Wooden

    Lew Morris
    1973 R75/5 - original owner

  5. #5
    Registered User
    Join Date
    Aug 2011
    Location
    Arlington, TX
    Posts
    15
    Thanks guys for the moral support. And maybe, just maybe I'm getting there as far as "mechanic" goes. When my final drive FAILED on the way to Sedalia last year I was able to locate a replacement and installed it and a new set of shocks myself.

    I get a lot of help from Bruce... and a buddy at work with a '73 R75. Next onto the carb balance. Carbs are still a little bit of a mystery to me, but I can read.

    thanks again

    brian
    1976 R90/6
    Member# 174498

  6. #6
    Registered User festes's Avatar
    Join Date
    Aug 2006
    Location
    Waldorf, MD
    Posts
    37
    Bruce is top notch and knows his stuff.

  7. #7
    Macrunch MCrenshaw's Avatar
    Join Date
    Mar 2008
    Location
    Bedford, TX
    Posts
    79
    Quote Originally Posted by festes View Post
    Bruce is top notch and knows his stuff.
    Absolutely. Best airhead mechanic I know of.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •