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Bore stroke CHANGE

Featured Replies

1 hour ago, larry s. k. said:

Hi any body know what year or models the stroke . Bore  changed 

Which engine are you asking about?

  • Author

Hi basically 250 and 350   Pursang alpine Sherpa  , I building. Engines and interchanging parts , cylinders  on all these models ,  213 192  199.  166 159 ,  wondering what year , I found 166 cylinder on my. 213  ,, so  I little confused  how far back change , I measured  piston skirt. , the older are defiantly shorter ,  say early 350 off a matador ,, some are different lengths on 350 around 5 inches , and more and less of what few I have , , any info might help , thanks 

I see you have M166 and M213 cylinders. These are 350 Alpina cylinders and will be for a longer stroke bottom end than the Sherpa T cylinders you mentioned.

The first "350" Alpina (M99) was actually 325cc and had a 60mm stroke.

The "350" Alpina models after the M99 were actually 350cc and this was from having the longer stroke. Because of this, the M166 and M213 cylinders will be longer than your Sherpa T cylinders.

Another thing that might clear up some confusion is that the number stamped on a Bultaco cylinder is usually the Bultaco model number that the cylinder first appeared on.

For example the first 5-speed 250 Sherpa T was the M27. The M27 cylinder is stamped 27. The following Sherpa T models (49, 80 and 91) also have 27 stamped on their cylinders.

This may explain why your M213 Alpina cylinder is stamped 116. M116 is an earlier model 350 Alpina than the M213.

 

  • Author

Great , thanks info  think some one rebuilt 213 many years ago  and Parker it , I picked it up from a picker ?   He never started it , had fuel in it looked dark , thought it was a ready runner  got it running  after 40 kicks  , was tired engine , so, back to drawing board find right , cylinder , have 166 , it’s needs boring if , fixable at last oversized, they charge 100. To bore and tax at our local machine shop , going look at  my spares ,  I cannot use 199  , upon info it’s 60 mm ,  it’s nice shape , I save for another , when working with older  250 so 68 pursang Alpina 85  parts interchange  , with no problem ,, ya always thinking how to put puzzle together ,  , and  really  liked 213  the way it rides. Thinking ,, that made changes around 1975 to 76   , , mk  models go all over  upon looking at production list , could not find any engine production on line , just.  Some info on bultaco changed bore stroke  for tax ,   Government regulation  

Pursang Mk5 and Mk6 325cc, Mk7 and Mk8 360cc, Mk9 and Mk10 and Mk11 370cc

The engine that changed capacity for tax purposes was the Sherpa T 250 and it went to 238cc

David, I salute you and I mean that sincerely.

You try to decipher the "indecipherable", I just smack my head on the table.

Edited by fourex

  • Author

 Thanks info site supporter feetupfun , ,, I need all info , help can get  ,  your in Australia , great  I shipped a model 70 short block to Australia , to bultaco Australia parts .com  a year or so ,   He is building a  el bandito ,  , I’m in different time zone   , cheers  ,larry

 

 

 

12 hours ago, fourex said:

David, I salute you and I mean that sincerely.

You try to decipher the "undecipherable", I just smack my head on the table.

Just have another XXXX ;)  That's how they spell beer in most parts of the World, but Queenslander's are different than most people ;)

19 minutes ago, eagle8 said:

Just have another XXXX ;)  That's how they spell beer in most parts of the World, but Queenslander's are different than most people ;)

Another had, and another and so on.:guinness:

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