Monday, June 8, 2009

S7 work on hold - something else is broken

The S7 engine work is temporarily on hold.  The crank went to the local NAPA machine shop last week.

I'll be trying to put a new main bearing (probably a new crank) in my Yamaha XS650 and get that cleaned up before I continue with the S7.  This will give me some extra time to consider how to place an o-ring in the head gasket to insure a good seal between block and head.  My initial thought is to widen the hole in the copper gasket to make room for the o-ring.  After that I can countersink the hole in the block until I get the needed crush on the o-ring.  More to come on this subject.


  1. The machine shop called and said my crank is ready. I'll pick it up on the way home.

    Just in time too... the Yamaha ran last night and I should consider it finished.

  2. Hi i'm too trying to get an S7 delux back to its former glory some parts you just cant get, i know of a guy who got his front forks made to exact spec from an original sent to him from Briton to the states because no one here could make them, and i was thinking if there might be anyone in the states that can make a dynamo to the same spec as original from 6v to 12v using the same size field winding case, in england they do a 12v upgrade that takes the place of the 6v but its not the same size and looks pants, it seems that no one in england can take up the chalenge, i read articles in classic motorcyle mags and tv programes that people from the states are eager to take the chalenge and supply or is this a mythe, i noticed by your articles that you use stewert's i do too,and your right were would we be without them, so is there no one in the states that can manufacture the parts ??? or are the brits the only guys that can make and distribute some of these parts and that some parts are obsolete and we just have to grin and put up with it.
    Best regards Russell
    Ps could you have got the rear bearing made in the states ?

  3. Russell,

    There are some things that are now made of Unobtainium. It seems distributors, and dynamo parts are worth their weight in platinum. There are things in the Stewart Eng catalog that simply are not available. They have to be made custom, or scavenged from another bike. I had to make my own cam chain tensioner parts.

    I probably could have gotten a local machine shop to make my rear main bearing. Or I could have spent hours and hours making it myself. The question would have been what material to make it out of?!?. Here's the important part. I don't want to take any business away from Stewart Engineering because of the simple fact that if I don't patronize them for the things the DO have... where would we all be without them? You are so right there.

    In the States you have to seek out someone who is an expert in British iron. I live in the city of one of the largest Harley-Davidson manufacturing plants. Everything is H-D. There are only a few other shops in the area that can service Japanese bikes. There is one shady old chop-shop, a lonely remaining relic of the 60's, that may have the know how for unusual things such as a Sunbeam. I've been to that shop, but don't get a warm reception. They have some of the most interesting bikes (Triumphs, old H-D stuff, and even two Nimbus bikes) ... however, they make me uncomfortable when I'm in there. Most of the H-D shops are friendly, but just don't have the experience to help me with really technical things. Most shops are bolt-on shops... they make their money doing maintenance and adding chrome for the weekend biker posers. Sorry for going on a rant.

    Anyway, there are custom places that can do parts, but no one specializing in electrical. Being an electrical engineer by training, I can usually handle these things personally. Re-winding stators or rotors is not unheard of. I do know shops that can do this as well, but they wouldn't be able to re-engineer it, only re-work it back to the way it was. I wouldn't say that there are people eager to jump in and make new parts, but they can be found. The problem I see is that these places are so few and far between, they don't advertise. My local Guzzi dealer... case in point... The also specialize in classic Porsche. Most people don't even know they exist. You have to find out about things through word of mouth. Gotta attend the shows, go to the museums talk to the docents, approach people with unusual equipment and find out where they get service or parts.

    If you can get the measurements on a part, you can use to custom make parts. Its really expensive, but they'll do a good job.

    Good luck on your rebuild as well! Send some pix if you are able.

    Thanks for the well wishes. I'm nearly there.