they all work!
December 24, 2011, 6:15 pm
Filed under: repairs | Tags: , , ,

All my bikes that can run are ! Newport still needs a tube and the frev needs the 19t sprocket put on and the chain run, but still, 4 running bikes plus my bros tomos. The frev turned out pretty decent. It runs fine, brake light works, and a 55w headlight! The seat mount isn’t perfect but it looks pretty good. Changes will come later when its all dolled up, but for now I’d like to just ride it. I can’t wait to take it for a spin! Riding chappy around again was a blast, especially after seeing some kids scooting around the hood on a pair of fa50s.


September 29, 2009, 6:00 am
Filed under: Uncategorized | Tags: , , , , , , , ,

So yea, Chappy’s are amazing. There were several different versions sold back in the day with 2 motors and different transmission arrangements. Most common are the LB50’s, which usually have foot pegs, and a 2 speed transmission that has 2 gear ratios (so that means 2 gears of Hi, or 2 gears of Low for hills). There is also the LB50PE which is the same, except it has pedals that are pathetic, but pedals nonetheless. The right pedal arm is also adjustable and can be locked in the forward position to act as footpegs. Yamaha also sold the LB80 (which is actually 72cc’s) with either the 2 gear dual ratio transmission or in very rare cases a 4 speed manual. The 72cc top end apparently isn’t swappable between bottom ends, but I’ve never had one, and I’d guess its like the 75cc puch kits where the skirt is too big for the case.

Stock the 50s are pretty slow. Chappy’s weigh an obscene amount, and the stock carb is tiny, so it really offer much performance wise. When I first got mine it did about 23 mph. Later on before kitting I got it up to a whole 28mph. To do this I did my first pathetic attempt at porting, got new piston rings and cleaned the exhaust.

Internally these are pretty intimidating motors, so beware when you take that transmission cover off. I’ll take a photo next oil change. Luckily everything is awesome yamaha quality, so it is very durable and over-engineered. My bottom end has thus far survived several hundred miles with the polini setup.

Performance wise, there isn’t a ton of stuff available, but at least there is some stuff. Polini makes a 70cc cylinder (45mm, rated at 6 hp), larger intake (for clamp on dellorto PHBG carbs); Ninja makes an exhaust, and Gianelli also makes a pipe. Thats it. If I were to do it again, I’d get some other pipe, maybe an 8p, motobecane ninja, or something else and weld it onto the stock (and MASSIVE) header. The chappy ninja exhaust is pretty, but it has a non-removable restriction and thats a huge bummer. You could cut off the header flange and graft on the one from your stock pipe, but that’s probably more work than most people are going to undertake. The gianelli also has a restrictor washer welded in, but it pops out easy. A derbi Big Muff might be good (too long though). Either Chappy pipe will necessitate the removal of pedals.

My bike has the polini (case matched), the intake, a puch 50cc high-comp head, gilardoni 4 petal reed block (some filing required to make it fit), gianelli exhaust and a 21mm phbg. My oil injection is disabled and I premix in the tank. The NOS and oil injection nipples on the intake are also blocked off.

Unfortunately to make the polini or ninja exhaust work, you need to lose the pedals. To make matters worse, you pretty much need a non-pedal chappy swingarm (narrower to account for smaller rear wheel hub). These are easy to find on ebay, and go on easy, but its just an added hassle. If you have the pedal version, the extra pedal sprocket simply unbolts from the rear wheel hub, narrowing the whole rear wheel so it can fit inside the non-pedal swingarm.

When first kitted I got it up to nearly 50 miles an hour. This is scary for such a small bike that is super squishy. It currently cruises about 40 and can get up to 45 if I want, maybe more, but thats just because the Gianelli has an obscenely long header so its all low end.

As I look back on this all, I now see I omitted discussing the electrical system. Yamaha points are solid, but the biggest issue is non-adjustable timing besides adjusting the point gap itself. The stator just has 2 holes holding it to the case with no room for adjusting. This can likely be fixed with some careful dremel or milling action, but I have no idea what the results would be (well probably faster, but I cannot say for sure without trying). Additionally, no other moped ignition system will fit due to the obscenely large diameter of the crankshaft.

Chappy Resources:
Treatland – Performance Parts
Bike Bandit – NOS replacement parts (select year, then model: e.g. 1978 LB50PE) Most parts cross over between years and models
eBay – any obscure part you may need

If you can’t find it here, France actually has a large number of Chappy’s, so french ebay is a last resort.

I’ll add a photo of the wiring diagram later on.