Re: The Official Yamaha Chappy (LB50) Thread!!!

Dirty30 Dillon /

> Eric Migliorino Wrote:

> -------------------------------------------------------

> Sounds like it’s time for a pw80 upgrade. That or be lucky enough to

> find an original 3 speed. Do both of you have an LB50 or an LB80? I

> think there is a difference in their rear hubs and not just the

> freewheel cassette. The LB80 has some sort of plastic pieces behind the

> rear sprocket in the hub while I don’t believe the LB50 has the same in

> it’s rear hub? Anyone know what this is?

Yeah, I need to buy some trans components for my PW80 and build an intake.

I have an LB50. I am sure that the LB80's plastic bits behing the sprocket are dampeners. to stop from sheering sprocket bolts.

Re: The Official Yamaha Chappy (LB50) Thread!!!

Eric Migliorino /

Take a look at Yamaha JOG intakes. That may help with getting a carb to fit.

Yeah the parts manual refers to those plastic parts behind the sprocket as dampeners. LB50 never had enough power to have the same setup for dampeners. Excited about the PW80 build. Keep us posted!

Eric

Re: The Official Yamaha Chappy (LB50) Thread!!!

Dirty30 Dillon /

> Eric Migliorino Wrote:

> -------------------------------------------------------

> Take a look at Yamaha JOG intakes. That may help with getting a carb to

> fit.

Sadly, the JOG's have a completely different bolt pattern. I most likely am going to end up fabbing an intake. I would love to use the stock carb, but we'll have to see if I can properly route things

Re: The Official Yamaha Chappy (LB50) Thread!!!

Jack Rutherford /

So my buddy liked my Chappy so much, he found one for himself. Problem is - it's a real basket case. I'll post pictures tomorrow. Anyhow, it's missing the stator among other things. Used stator on ebay is $90. The flywheel appears to be the same size as the qt50 flywheel. I need to take the flywheel off and determine if qt50 stator would work and, if so, consider converting to cdi.

any thoughts?

Re: The Official Yamaha Chappy (LB50) Thread!!!

Jack Rutherford /

the qt50 stator will bolt/screw up to the Chappy. I'd have to reroute the wires coming out of it a bit. I think I could just use the Chappy flywheel with it. The Chappy flywheel is just a little thicker than the qt50 flywheel. If I want to go through with it, I'll have to look at some wiring diagrams.

Re: The Official Yamaha Chappy (LB50) Thread!!!

Eric Migliorino /

Depending on how much is missing, CDI may be cheaper and would be better in the long run if you plan on modifying heavily in the future. What else is missing?

Re: The Official Yamaha Chappy (LB50) Thread!!!

Jack Rutherford /

So far the stator, stator cover (someone actually rode around without a stator cover as there are little pebbles and plenty of dirty in the flywheel. Two washers before the flywheel nut are missing. I see the four wires inside the frame where the stator plugs into but they are individual wires. From what I've seen, it looks like there should be a four prong plug to plug the stator wires into. No big deal but that's missing.

It's also missing headlight, headlight bezel, all the wires have been taken out of the headlight and disconnected. No battery. And I'm sure other things. I'll dig further.

Re: The Official Yamaha Chappy (LB50) Thread!!!

Jack Rutherford /
chappycarb.jpg

The hits keep coming.

Re: The Official Yamaha Chappy (LB50) Thread!!!

Eric Migliorino /

The 4 wires with bullet connectors instead of a plug is not out of the ordinary. I think the chappy’s started with the bullet connectors then went to the plug. See picture of a stator off a ‘76 chappy.

The broken tube will on your carb is the pilot jet. See picture of pilot jet on my carb. Yamaha still makes these. Best bet is using a heat gun to warm up the carb and ease the process of removing that jet. Obviously make sure there is no gasoline when heating up the carb still hiding in it. It probably broke when someone tried removing it. Be careful because stock carbs are hard to come by. Good luck.

Sourcing a headlight won’t be bad and get a wiring diagram to figure out what wires are missing.

Keep us posted as to your progress and ask questions if needed.

Eric

BE95C060-D0C3-4DB1-9728-D2F32A792887.jpeg
15778376-4D90-4CF6-B637-BBB15407B0CE.jpeg

Re: The Official Yamaha Chappy (LB50) Thread!!!

Jack Rutherford /

Ok that's helpful. I should've looked at the idle jet on my other Chappy. So that was a slot for a screwdriver. I wonder if it will run as is since the hole is still at the level it should be.

Re: The Official Yamaha Chappy (LB50) Thread!!!

> Jack Rutherford Wrote:

> -------------------------------------------------------

> Ok that's helpful. I should've looked at the idle jet on my other

> Chappy. So that was a slot for a screwdriver. I wonder if it will run

> as is since the hole is still at the level it should be.

I would think it should function just fine , if it's clean clear through .

Re: The Official Yamaha Chappy (LB50) Thread!!!

Jack Rutherford /

The owner of the 2nd Chappy in my possession is acquiring a parts bike so I'm waiting on that to happen.

Anyway is this HPI system worth all the corn? I mean, at least this one is less outrageously priced than the one for the qt.

hpi.png

What advantages does it have over stock ignition system?

Re: The Official Yamaha Chappy (LB50) Thread!!!

Bike will rev up quicker. Flywheel significantly lighter

Re: The Official Yamaha Chappy (LB50) Thread!!!

Just picked up a LB50!

92941BD9-1758-4373-86CF-207DB2F21384.jpeg

Re: The Official Yamaha Chappy (LB50) Thread!!!

Jack Rutherford /

Beautimous!

Re: The Official Yamaha Chappy (LB50) Thread!!!

Eric Migliorino /

12 volt system means brighter lights. Solid state ignition will be more reliable, no that the stock 6v system isn’t. I’m thinking your timing will be adjustable whereas stock stator just bolts in one way, no adjustment.

Re: The Official Yamaha Chappy (LB50) Thread!!!

Eric Migliorino /

Congrats! Welcome to the Chappy world!

Re: The Official Yamaha Chappy (LB50) Thread!!!

thank you! second Chappy actually, have a LB80 as well. Hopefully this new LB50 will allow me to answer more LB50 specific questions. Its an interesting creature with the pedals. Mild performance build coming soon (edited)

Re: The Official Yamaha Chappy (LB50) Thread!!!

Took the LB50 out today for its maiden voyage alongside my LB80. LB50 is low miles and very well taken care of by previous owner. Carb clean, exhaust cleanish, no leaks at head, cylinder, intake, exhaust etc. Fresh fuel, oil, and plug. LB50 will only do 21mph (13/32) gearing. Had a spare 28tooth sprocket laying around so swapped to 13/28 gearing and picked up 4mph, which is expected. Top speed 25 now whoooo!!! Obviously I cant expect the same performance as my LB80 but is 21mph typical for a completely stock LB50??????? (edited)

IMG_0935.jpeg

Re: The Official Yamaha Chappy (LB50) Thread!!!

Jack Rutherford /

"There is a very large difference between the LB50 and LB80 models. While the engine's lower ends of each model are usually identical, the 50cc top end does not pack enough power to push the bike any more than about 21 to 23mph (depending on the rider's weight)."

Re: The Official Yamaha Chappy (LB50) Thread!!!

Yea thats what it appears. Thanks for the info. Good to confirm the stock top speed was within reason. Looks like bike will get the polini kit and MLM pipe. Going to run the stock intake and carb for a while and see how it performs.

Re: The Official Yamaha Chappy (LB50) Thread!!!

Yamaha LB50 overview and test ride (stock)

I apologize in advance for the canted camera angle at times. Video just showing off the bike and stock performance, will serve as a baseline for comparison once Big bore kit, high compression head, pipe, and taller gearing are installed

Re: The Official Yamaha Chappy (LB50) Thread!!!

Great video!

Do you know what shade of red that is? My sister has the same year Chappy, that's currently being fixed and we are looking at touch up paint.

https://www.colorrite.com/product/yamaha-00e1-chappy-red-cpr-1790.cfm

Thanks!

-Michael

Re: The Official Yamaha Chappy (LB50) Thread!!!

Thank you! I'm not sure about the color red or the paint code. The image included in the link you provided looks a little more purple than the color of my Chappy. But then again the website states the color is approximate. I will check to owners manual when I get home for the off chance its mentioned in there.

Re: The Official Yamaha Chappy (LB50) Thread!!!

Eric Migliorino /

Chappy red is the correct color. If you look at later model Yamaha’s using the same red color, they still refer to it as chappy red. Note due to the age of the paint on the bike, they may not come out as exact match. Depending how crazy you are about how the bike looks, it may be better to repaint the whole bike, but that’s easier said than done.

Eric

Re: The Official Yamaha Chappy (LB50) Thread!!!

Roger that, thank you Eric!

Re: The Official Yamaha Chappy (LB50) Thread!!!

Eric Migliorino /

Stock chappy does 23mph on the flats if you have a fast one! MLM pipe alone got me to 28mph on the flats. You can also modify the stock pipe to make it less restrictive. A chappy I bought, someone cut the muffler, I assume removed the baffles inside and welded it shut again. The spark arrestor is removed too. I had quicker pick up with that mod but it topped out at 27mph. Also note it was about 30% louder than stock. The MLM pipe is only a couple of decibels louder than stock.

I also just put on a lightly used Polini kit with MLM pipe on my son’s chappy with stock carb and it actually got slower! The issue is the carb is way too small and not tuned for the bigger cylinder and free flowing exhaust. My recommendation is to put effort into tuning a bigger carb instead of wasting time rejetting the stock carb. Options for bigger carbs would be LB80 carb or pw80 carb if you want to keep the stock intake. Not sure whether the pw80 carb will be plug and play like the LB80 carb as the main jet is a 120 vs 90 main jet in the LB80 carb. Mikuni VM18 or VM20 or Dellorto 19mm, are other options but all require aftermarket intakes - MLM or Polini intakes.

Last to consider is if you want to keep the oil injection. The LB80 oil injection has a different size plunger within it’s pump than the LB50, so it puts through a little more oil. Not sure how much it matters with today’s oil technology as so much has changed between now and then. You probably get more protection with a little less oil for today’s oil vs that of late 70’s/early 80’s. You can also remove or disable the oil pump and premix.

Good luck and anybody else feel free to chime in.

Eric

Re: The Official Yamaha Chappy (LB50) Thread!!!

Dirty30 Dillon /

If I could do it again, I would grab the Polini intake for Chappy and run a PHBG 17.5 or so. The VM20 is too much carb for a bike that can't have any tuning done to the clutches in order to rev through the port stall.

Prior to the VM20 I was running a SHA and it was grand.... in fact maybe I will go back.

Re: The Official Yamaha Chappy (LB50) Thread!!!

Eric,

Thank you so SO much for your insight. This sheds light on a lot of my curiosity. My polini kit comes in tomorrow. Additionally, I have a couple spare stock exhausts. I think I will cut one of them open, at the very least for informational purposes, and see if I can replicate the results your bike had with the stock modified pipe. My suspicions with the carb being too small for the cylinder and pipe seem to be confirmed. The MLM pipe for the Chappy is a big girl, with an even bigger header diameter. I know in my experience, and I believe Jack's as well, the LB80 bottom end suffers dramatically with the MLM pipe, over the stock setup. Furthermore the gains up top are rather small compared to other bikes with MLM pipes. I would imagine the MLM pipe does even more damage with the slightly smaller displacement and smaller stock carb. An LB80 carb is certainly in my LB50's future, assuming I can find one LOL, but for the time being I will try and work out the best combo with the stock carb.

Thank you again!

Hunter

Re: The Official Yamaha Chappy (LB50) Thread!!!

Dirty30 Dillon /

Dellorto SHA's clamp right onto an LB50 intake once you remove the plastic shim.

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