Piston size on what did you do to your Bultaco today. Hi bultacorock,Mahle Pistons are all made to a nominal size,such as .50 oversize for instance. When finally machined they may be fractionally under or over size. The minus sign on yours indicates it is just a little under size. Each piston is carefully checked then marked before being boxed for sale.That is the marking you see. When a cylinder is sent out for re-boring the replacement piston needs to go as well so as the machinist can hone to a specified clearance. What you have discovered by accident is Bultaco quality ! Hope this helps,John.

None as far as I know, the difference is in the primary gearing. These make great trials motorcycles with very few changes.

 

Thanks for the reply.I,m not sure which way I will go with this project just yet,but a replica Sherpa T is one thought.

Hi Scot Taco,I have had a look at my listings for you. The Matador Mk 2, model M 16 gear ratios -0287...0482....0683..& 1 to 1 for top gear. The first Sherpa T,model M10, is-0350...0454...0831..& 1 to 1 for top gear. A fair bit of difference. If you had an idea to use the Matador for trials I would suggest just to find a M 10 motor in good order then swap over. The later Mk 3 Matador had a 5 speed box. Hope this helps,John.

Thanks for that John.The m10 Sherpa motor is rare as hens teeth here.The more I,ve thought about it the more I,m leaning towards keeping it what it is.

 

If I could find an early Sherpa S tank and high pipe I would maybe put those on it just because I love the looks of those.

 

4 speed Bultaco's are great to mix and match parts. I built a 1966 Sherpa Scrambler with a Matador top end and a Mercurio close ratio gear box lower end.

 

http://bultacoforum.com/index.php?topic=267.0

 

 

https://davidarmstrong.smugmug.com/My-First-Gallery/

 

I also ran a 1966 Matador 4 speed set up as a trials bike for about 7 years, only recently selling both the Sherpa s and trials bike to the same young guy.

Dusted em off and went for a ride!

My friend Alex on his 250.

Oops.

4 speed Bultaco's are great to mix and match parts. I built a 1966 Sherpa Scrambler with a Matador top end and a Mercurio close ratio gear box lower end.

 

http://bultacoforum.com/index.php?topic=267.0

 

 

https://davidarmstrong.smugmug.com/My-First-Gallery/

 

I also ran a 1966 Matador 4 speed set up as a trials bike for about 7 years, only recently selling both the Sherpa s and trials bike to the same young guy.

 

Dave,

 

Those two Buls that you built are pretty cool! They are hard to beat because they are so easy to work on and you can mix and match a lot of different parts.

 After seeing the photos I recognize you and the MXer from the Hammer and Tongs site.It seems like you guys have a good vintage following out there.

 

Thanks for the links.

Tripp,

 

I had to look twice to see who was riding your bike.

 

No whiskers!

Had to do some work at Solvay Polymers. No beards allowed!

I was actually able to get out and ride it over the weekend although I did end up on the Ossa for most of the time because my brother was more at home on the Bul.

 

 

 

 

 

Finally got round to replacing the foot pegs on my 198a.

Cut the originals off leaving the outline of originals so the welder could get a measurement, they have actually gone back 5mm and down 10mm, not much of a change.

Just primed the metal hangers and surrounding exposed frame, ready for spraying tomorrow.

Nice job hoping to get 2 off mine done.

Edited June 19, 201610 yr by bondy

Thanks Bondy,

Just put it all back together and wow what a better feeling, I know the purists will probably be having kittens but it feels so much more comfortable and balanced............... I like them.