Hello Morris, and fellow mopedeers, At 19:08 29-4-00 -0700, you wrote: >I recently purchased a '90 Yamaha Riva Jog for my wife to ride. It's got a >little over 1000 miles. I also have '79 Puch Magnum MK II with 9500 miles. > >The Jog has buckets more power than the Puch, even though they're both 50 >cc. Any ideas on why this is? I've been thinking of selling the Puch >'cause it won't quite make it up the hill to the house. The Jog hauls at >20+ with no problem. The main difference in the layout between these two bikes is the transmission. The Puch has a rather old-fashioned centrifugal-operated two-speed gearbox, the Yamaha (Minarelli engine) uses a variomatic transmission, which is much more flexible in use. On top of that there is a 15-year gap between the construction of these engines. The Yamaha has (amongst others) reed valve and electronic ignition. The Yamaha always will have more power, and pull up hills much better as that Puch (or Tomos) in any condition. Your Puch should shift into 1st gear automatically, and crawl up that hill anyway though. Here's a list of known Puch (or Tomos) problems, which might apply to your Puch (in sequence of probability) 1: Clogged exhaust or exhaust muffler; clean or replace 2: Wrong reduction of cogs; (should be 16front -40rear or 15-45) 3: Ignition off timing due to wear; replace contact-breakers and adjust timing (1.5mm BTDC) 4: Leaking oil-seals; replace 5: Worn Cylinder and/or piston/rings; replace >The Puch seems to run will enough, just not enough grunt to make it up the >hill. The plug is new and I had it serviced recently by a knowledgeable >moped mechanic. Any thoughts? If that mechanic is any good, 1,3 and 4 should not have escaped his attention during service. How steep is that hill in percentage? If it's about 10 or 15 percent, the Puch will never take this one easily. Cheers, Newsletters, Tips and Discussions on Your Favorite Topics
|