After racing my first 100cc class last weekend I have some thoughts relative to the Penton and its competition.
The bike I rode was a stone stock Berkshire engine except for the 28mm Mikuni. My competition was a '74 Yamaha MX100. The reed valve Yahama had a bit more acceleration than the Baby Berkshire but not much. The one thing the Penton has the no other bike in the 100cc class has is stability[/i]. The back straight was a fourth gear straight. In my second moto I only had first through third gears, but the short wheelbase Yamaha was head shaking and tank slapping so bad on the back straight that he could not pull away from me even though I needed one more cog than I had. If there is ever a track where a Penton could use fifth or sixth a Hodaka or Yamaha would be so frightening they would have no chance.
So, for anyone thinking of building a 100cc Penton I say absolutely do it. Provided you can keep a 100cc piston port Sachs on the pipe a Penton 100 should be the bike to beat.
Brian
Great observations Brian. If you are ever in Springfield Mo. you can stop off and see the 100 Penton that beat them all....DG, FMF and all the others. Larry Perkins did win the 100 Expert School Boy Championship at the Astrodome back in the 1970's. Great history and a Great Rider.
Ron Carbaugh
But not on a stock engine. FMF did my engine back in 1974 and that motor would outrun a stock 125 no problem.
What is stock?? I think we put a different rear tire on it;)
Ron Carbaugh
Tiddler rules experts,I have a Berkshire 100 cylinder with a period pumper carb (maybe Kendrick Engineering?)i got from T.B..Should i even attempt to go thru tech with this set-up?i saw nothing in the rules about pumpers and used to race a Kendrick modded 6 days back in the 70's,so i would think it would be a period correct mod.I'm sure it would be legal unless i won![xx(],then a protest would follow for sure,right?;)
ric emmal
Pumper carbs are not legal.
11.2.c
CARBURETORS: Flat-slide or Lectron type and injection type carburetors are not permitted. "Power Jet" and "Pumper" type carburetors are not permitted unless such mechanisms are disconnected or removed. Fuel injection is not permitted. Period carburetors are encouraged. Smoothbores with concentric float bowls are not permitted, except where they were fitted as original equipment or supplied as factory kits on that model motorcycle. Modern replacement smoothbore carburetors are not permitted.
I cant speak for a Regional, but you wont get that through tech at a National unless you disable the pumper function.
Brian
Quotequote:Originally posted by brian kirby
Pumper carbs are not legal.
11.2.c
CARBURETORS: Flat-slide or Lectron type and injection type carburetors are not permitted. "Power Jet" and "Pumper" type carburetors are not permitted unless such mechanisms are disconnected or removed. Fuel injection is not permitted. Period carburetors are encouraged. Smoothbores with concentric float bowls are not permitted, except where they were fitted as original equipment or supplied as factory kits on that model motorcycle. Modern replacement smoothbore carburetors are not permitted.
I cant speak for a Regional, but you wont get that through tech at a National unless you disable the pumper function.
Brian
He is talking about a chain saw style pumper carb. This was a hot setup in the early 70s. Probably legal but not nessesarily better than a good Mikuni or Bing setup.
Dwight
Darn Ric...I was hoping you could go out with turbo cylinder a throw chunks!!
Glad all you 100 guys had a great time! I have been tossing around a little something to liven up the class a bit and possibly peedle off a few 125s.
I think the 100cc in MO may be a fun place for it since it is Exotic Rat Heaven. We will see how the summer goes with the modern bike schedule.
TB
Tom, Make time for Mid-O and be sure and bring some Rat poison [8D]. 100cc class winners at Ocala were: Yamaha -Exp, Suzuki - Int., Hodaka - Nov. Pentons have yet to take an overall, although Brian did score one moto win. The Rats are a force to recon with - the shear numbers can be overwhelming. And, they do bring some super doper handy work to the races. There is nothing in the rules to prevent any 100cc bike from extensive chassis & suspension mods to bring them up to and surpass the best ... and we know those oriental engines can scream[}:)]. The 100cc class is gaining momentum and will grow. Build one.
Next race is Diamond Don's. Kid Christopher can't attend because of school work and soccer ... maybe I can slip the Baby Berkshire out and give it a go ... Good luck with your modern program.
Ernie P.
Chattanooga, TN
Tommy,I'll see if i can get someone at ahrma to give me an opinion on the "secret works" cylinder.What's all this i hear about modern bikes -you can get hurt on them things!Ric
ric emmal
What year Super Rat is everyone racing? If it is the 1974 model, a stock Penton will need to be GS'd to run with them. Mill the head .060, open the ports, and cut off the muffler and stinger and replace with a soundmaster tip then you will have a bike that will get the job done.