Differences beween a Birky and a sixday

[tomale]

Maybe some of you have heard or maybe some of you have the same thing going on in your neck of the woods. anyway there is a ground swell of intrest in racing the 100's out this way. I have been working on collecting parts to build a sixday but I have been thinking that maybe what I want to do is build a birkshire instead... I know that the bottom end on a birkshire is the same as the Sixday but is there other differences that I should be aware of. The plan is to set it up in MX trim..Thanks in advance.

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
75' GS400 (project bike)
72'sixday (project bike)

[Doug Wilford]

The Head , Cylinder and Piston are the only major differemces.  Gearing amd carburation should be changed.   The internals in the engine are the same.
Have Fun!

[Larry Perkins]

Thom

If you go that route let me know and I can turn you on to the hot porting, pipe, and carb specs for the Berkie.

Larry P

[tomale]

Doug, what kind of changes need to be made to the gearing, (smaller countershaft sprocket?)
Larry, I have a pretty much complete 100cc motor but I am thinking the bore may already be on it last rebore. I need to figure out what to do, I could have the top end resleeved, There is a local guy that is really good, (Seperior Sleeve) but I figure that makes it more money than I can really afford to spend.. I am thinking that I really want to do it but this is the kind of thing that is holding me back... I believe the bore is already at 50mm. I have a really nice pipe so at least I do have that, I do not have a carb for the bike, but then I had planned on that already.
If I do this project larry I will let you know, thanks to both of you!
I think it would be cool to have a racing birky. I see alot of Hodaka's and a buddy of mine just finished a really nice TM 100 and then there is a yz100 that spit it's way to the finish line...It would be great to see something alittle out of the ordinary... Thanks again!

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
75' GS400 (project bike)
72'sixday (project bike)

[deek]

Thom, get it going, that will make 2 of us with 100cc!! Still need the tank painted Red though.

Hi Larry, didn't make it to Springfield this year, but trying next year.

Would you send me the hot tips for the 100cc Birkie.

Dale

[tomale]

Thanks Dale, several guys are encouraging me to build it. Can you imagine me on a 100cc bike? Still there is nothing like riding a small bike to build corner speed. My friend Tom Mc is going to help me with refurbishing the wheels, and He may have a piston for the bike. The problem is that I think I am at the last oversize for a piston. so I may have to do something different. We are looking into several Ideas, one step at a time.

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
75' GS400 (project bike)
72'sixday (project bike)

[Doug Wilford]

Tom;
The 100cc for sure, the gearing should be at least 13 X 60.   Do the project, I think I might be able to find a useable 100 cc cyl, when you need one!

[VICTOR MONZ]

Doug:

I am in the process of building a 72 100 Berkie...could I get the "hot" specs, etc. for my fall/winter motor project.

Any assistance will be greatly appreciated.

Also, I will be proudly flying the PENTON Banner on July 15th at Amago Racetrack in San Diego at a CALVMX sponsored race. I'll get Al some pictures for your sharing at the Board Meeting.

You all sure know how to make a guy feel special....I just close my eyes and feel like I'm back at Meadowlarks' starting gate with a full line of Pentons.  Anticipating the challenging harescramble track Dane and Jackie used to set up...I have finally figured out how they got through those trees my handlebars would bang into...they cut the bars down !

Thanks again.

Victor Monz

[tomale]

Tnanks Doug, I will let you know, as soon as I get that far. I guess I had better get busy, The 400 is coming along too, I hope to have it ready for a race july 8th, we will see... My current race bikes still need to come first, and so that takes away from getting too much done on the projects.... I hope to have the 100 ready for Chehalis in August.., that maybe a bit of a stretch....

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
75' GS400 (project bike)
72'sixday (project bike)