DMW Puch e50 Basic Upgrades. Should you build above or below 8,500 RPMS?!?

January 17, 2022

A lot of people reach out asking how much it would cost to make their Puch mopeds go “faster.” The great thing about building Puch motors is that it is the brand with the most parts availability and knowledge our there.

A good stock brass bushing Puch crankshaft is *typically* good to about 8,500 Rotations Per Minute. SO when adding power to your already functioning Puch Moped; the question is, should you leave the bottom end intact add only enough power to safely stay under 8,500 RPMs; OR should you rebuild the whole motor with a new needle bearing crankshaft, allowing you to *more or less* rev the bottom end as high as your cylinder / carb / pipe allow?

The following post reviews 3 “standard” affordable options for adding power to your single speed Puch e50 Moped given parts pricing at the start of 2022 & the goofy supply chain issues we are still seeing from the pandemic.

Of course, you can always spend more on parts or cut corners, and each builder has their personal favorite & least favorite parts. In addition to these basic parts, you may NEED to add other parts for your bike to run correctly, and these parts won’t make your bike run correctly if installed incorrectly. These are just some parts combos that we have had good success with building bikes for customers that are relatively reliable and budget friendly… for moped parts – lol.

*On Magnum style e50 cylinders with angled ports and different intake spacing; you’ll need magnum specific parts for options A or B.

**On Puch ZA50 2 speed motors, you’ll want a taller intake, better low end exhaust, and even taller gearing.

***On any tube frame Puch (Magnum, Murray, Series B, Sears Freespirit, JC Penney Pinto, JC Penney Swinger, etc..) you’ll need a different air box option.

Option A: Standard affordable set of basic upgrades to stay under 8,500 RPMs without touching your bottom end or stock 50cc cylinder. This allows the bike to “breathe” by letting more air in the larger carburetor, intake, and less restrictive air box. It allows more air out through clean new affordable European performance exhaust. The high compression head will add some punch off the line & the larger front sprocket with help convert the increased power to drive. This will achieve top speeds between 32mph & 42mph; most riders will hit the mid-high 30’s. Actual top speed after the upgrades will vary based on the condition of your pre-existing parts; cylinder, crankshaft, bearings, seals, ignition, transmission, etc as well as rider weight and mechanicals. Labor is $90 for 1 hour of assembly labor & $90 for 1 hour of tuning; for a total of $370.99 on top of the cost of a full tune up when done in conjunction with a full tune up. If a full tune up is not completed, a few additional line-item charges will be required. The specific components may be upgraded for additional charges & the labor would remain the same.

Option B: Standard affordable set of basic upgrades to stay under 8,500 RPMs with a brand new larger top end, while preserving your stock carburetor and exhaust. This will typically be more fuel efficient and more powerful off the line than option A. This option *more or less* keeps the same fuel consumption as the stock set up, but pushes the fuel and air through the motor much faster and more powerfully. The 65cc cylinder kit & high comp head turns the crankshaft with much more power aided by the larger intake, and less restrictive air box. The larger front sprocket will help convert the increased power to drive. This will achieve top speeds between 32mph & 42mph; most riders will hit the mid-high 30’s. Actual top speed after the upgrades will vary based on the condition of your pre-existing parts; exhaust, crankshaft, bearings, seals, ignition, transmission, etc as well as rider weight and mechanicals. Labor is $150 for the top end rebuild labor & $90 for 1 hour of tuning; for a total of $404.98 on top of the cost of a full tune up when done in conjunction with a full tune up. If a full tune up is not completed, a few additional line-item charges will be required. The specific components may be upgraded for additional charges & the labor would remain the same.

Option C: Standard affordable set of basic upgrades to every standard component including the crankshaft. Removing the motor and rebuilding it, replacing the stock brass bushing crankshaft with a modern needle bearing crankshaft accompanied by news bearings, seals, and gaskets will allow your motor to accept the 8,500+++ RPMs that you will achieve when upgrading carburetor & exhaust, AND installing a big bore kit. Just like the other options, the larger front sprocket will help convert the increased power to drive. This will achieve top speeds between 35mph & 50mph; most riders will hit the low-mid 40’s. Actual top speed after the upgrades will vary based on the condition of your pre-existing ignition and transmission as well as rider weight and mechanicals. Labor is $325 for a complete motor rebuild, $90 for 1 hour to remove and reinstall the motor, & $90 for 1 hour of tuning; for a total of $948.29 on top of the cost of a full tune up when done in conjunction with a full tune up. If a full tune up is not completed, a few additional line-item charges will be required. The specific components may be upgraded for additional charges & the labor would remain the same.