Penton Owners Group

General Discussion => Penton Talk => Topic started by: auto on November 12, 2019, 09:52:42 AM

Title: 1974 250 gearing
Post by: auto on November 12, 2019, 09:52:42 AM
I built a 74 250 and have a few questions.What gearing is most used,Are the trans ratios differant (closer) in a 1980 6 speed,different carb besides the bing and if so what air box boot would be used. It runs clean,just seems a bit lazy. Thanks
Title: 1974 250 gearing
Post by: JP Morgen on November 12, 2019, 12:17:05 PM
Very difficult to install a Mikuni and get an air boot set up. Buy a new needle jet for the Bing, they wear out and it makes the mid range jetting rich. Do the Carl Cranke porting, it will not be doggy!
Title: 1974 250 gearing
Post by: Carl Hill on November 12, 2019, 06:38:47 PM
I have a Bing on my 74 250 and it runs crisp and clean. They do wear quickly though as others have pointed out. My cylinder is stock, just matched up the ports. I have pulled quite a few holeshots with it. If yours feels slow I suspect you may have worn slide or needle.
Title: 1974 250 gearing
Post by: auto on November 14, 2019, 09:16:44 AM
After searching the forum I found answers to my questions except the ratio question.Are the gear ratios different in a 1980 250 from my 1974 transmission.Any links to parts list?
Title: 1974 250 gearing
Post by: Mike Lenz on November 17, 2019, 07:32:42 PM
I believe they are the same