Print Page - Need '77 250 Specs

Title: Need '77 250 Specs
Post by: Bob on June 15, 2003, 11:29:52 PM

Can someone tell me if 71mm is standard bore for a 1977 Penton 250 ?

Is 71.25 first over ?

What is the piston-to-cylinder clearance and ring end gap ?

Thanks,
Bob in Va

Title: Need '77 250 Specs
Post by: tofriedel on June 16, 2003, 09:04:22 AM

Bob,

71mm is the correct std. bore. The piston clearance is .050-.070mm for the 250.
The piston ring end gap is .15-.20mm

Tony

Title: Need '77 250 Specs
Post by: Larry Perkins on June 16, 2003, 11:30:02 AM

To the best of my knowledge 71.25 is like a half size over and were made by Wiseco. The Mahle KTM pistons I believe were 71mm, 71.50mm, 72mm, and 72.5mm. That is my memory.

Title: Need '77 250 Specs
Post by: Bob on June 16, 2003, 01:06:31 PM

Thanks guys.

Larry I have an original KTM / Elko piston which is 71.25. The part number is 543 30 007 201. I hope this is correct for my '77 250

Penton Owners Group

General Discussion => Penton Talk => Topic started by: Bob on June 15, 2003, 11:29:52 PM