Showing posts with label performance. Show all posts
Showing posts with label performance. Show all posts

Sunday, October 14, 2012

Leon's Peugeot 103 SP Rebuild

Treats sent Leon my way to fix his trusty ol' pug 103 SP....can you say basket case? We later found out it had been knocked over in a line of motorcycles and wrecked twice. This explained why the end of the crankshaft had broken off in the flywheel and the axle mount on the front fork was busted off. We replaced the front end of the bike. There were several vacuum leaks from worn seals and a Malossi intake that was not very well cast and had to be milled flat. Oh yeah, the bearings were shot, too. The bike had all the symptoms of coil failure, a very common pug problem (or any moped with original internal ignition coil). However, we had to get the flywheel off to replace the coil, which involved drilling out the bent & broken crankshaft after blowtorch & pullers did nothing except rip the threads off the flywheel (and my puller). Therefore, we had to replace the crank & flywheel....ie, total rebuild of the bottom end of the motor. No problem, except the first crank we got was out of spec. The threads on the variator side were .1 mil off and had to be re-tapped. When we tried to fire it up, it quickly became apparent that something was not right, and turns out the lobes were off by about a mil from being the right width for the case. Although it was properly shimmed & centered when assembled, it quickly wandered under the stress of running. It was replaced with a Gilardoni crank, which worked flawlessly. As the only available internal ignition coil was too small, CDI was the only option for electrics. This CDI was installed. No problem with the CDI, but the flywheel was junk: the glue holding the magnet to the housing didn't, and the timing mark flew off....Treats replaced the defective flywheel with this one and once installed, the bike ran like a champ. 



Yikes.









DIY woodruff key (no stock key, remember?)




Chinese

VS.



Gilardoni


Re-assembly!

Monday, June 18, 2012

sachs g3 performance clutch tuning



Stock Vs. Performance

Installation tutorial




So the stiffy springs went into the clutch part number 20 without too much knuckledragging and yep, not only do they work, they work better than stock, 'cause they're 15% stiffer. Testbed is my "problem child" sachs g3 w/ 505 /1A engine 48mm athena reed valve, 19mm Mikuni from a Kawasaki KH125 main jet 80 pilot 45 needle one notch from lowest, ghetto hacked biturbo pipe, stock gearing 43 mph top speed @ ~10K RPM. Frankly, it's ghetto as hell, and I know for a fact that I need new rings, but I digress. The clutch spline (No. 18) has been drilled and tapped for a set screw (w/ red loctite), plus two red loctited axle nuts tightened against each other on the end of the crankshaft (No. 12). So far, no problems with slip there. I have no tach so I'm guesstimating, but my guesstimate is engagement occurs ~1k, and the engine spins up enough power to make the clutch plates slip under extreme loads, but that's another problem most likely related to not having a shim in there. I'd say its a ~20% increase on stock takeoff engagement of around ~800 rpm. The bike takes off up grades that were previously impossible. As always, there is room for improvement. I look forward to hearing what people running superclutches or milled clutch plates have to say about their experience running these springs. If you're one of these folks that would like to replicate this experiment in yr own lab and report back with the lowdown, hit up OB1 to hook it up. Pix or it didn't happen:






Saturday, February 25, 2012

1976 Yamaha DT 100 Cafe Racer






64 mph
12 hp @ 7,000 RPM
Tuned carb
Oil pump deleted for premix conversion
Re-geared 17 x 36
5 speed gearbox
Tuned clutch engagement for rocket-like take-off
Re-wired - voltage regulator, hi & lo beam, brake lights, instrument cluster, neutral light, & custom ignition switch. Battery free!
Custom headlight lens uses 1157 or equivalent bulbs
Custom bodywork & fairing
Clubman bars
Underseat storage
Locking steering
Helmet lock
Historical plates - Tax free status!
Title

ob1 repairs coast to coast
props to Len at Autobahn in Cincy