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

Dirty30 Dillon /

You'll have to be more specific about not shifting well. If your carb tune is off it will struggle and hunt to get into the revs to slip into second.

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

Eric Migliorino /

> Michael Blank Wrote:

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

> Moped Army,

>

> I have three additional Chappys, all LB50s other than the LB80.

>

> 1 - Red 1980 *I believe*

>

> Added polini 70cc 45mm cylinder kit

>

> Replaced carb with non OEM so now the white housing plate doesn't sit on

> top of frame.

>

> Runs but looking to get it to run higher than 22mph.

>

> -I have an exhaust from treatland but haven't installed it yet, would

> have to remove the pedals which are stuck(locked) into place.

>

> 1. Have you guys had to cut off the pedals

>

> 2. will the exhaust installation get me higher mph to over 30mph

>

> 3. Are there any additional upgrades that need to happen?

>

> 2. Blue 1981 *I believe*

>

> The bike is almost 100% completed with parts but doesn't run.

>

> I have an LB80 motor that did run and I wanted to know if I could swap

> the engines and get this LB50 to perform better?

>

> -To make that happen what would I need to do?

>

> 1. Change rear sprockets

>

> 2. modify bicycle pedals

>

> 3. add new non oem exhaust

>

> 3. Blue 1980s..

>

> --Parts bike- Frame with stuff and no motor.

>

> Was thinking of adding the LB50 motor from bike #2 if the LB80 engine

> fits and slowly add parts to get it running.

>

> I'm trying to keep as many of these chappys on the road, where I live

> there is actually a good amount still running on the island.

>

> Thank you all for your help,

>

> -Michael

Mike,

Although much of this has already been answered, I’ll give my input too.

1. Chappy with Polini 70cc kit should get you well above the stock 22-23 mph. If you still have the stock carb, try going back to that. Main jet will probably be a 70 and idle jet will be a 15.

DO NOT CUT THE PEDALS OFF!! Where do you plan on putting your feet? If you must remove, start on the shifter side by removing the crank - one nut and pin. Then tap through swingarm. Don’t cut anything!

Exhaust won’t matter if carb not dialed in. Best to get running correctly stock than start throwing parts at it.

When you do go to aftermarket pipe, I’m thinking the main jet will need to go to a 90 or 95 main yet. Later LB80’s with carb more like LB50’s came with 90 jets but the slide and needle were different too. Idle jet stayed at 15.

2. LB80 engine should fit in the LB50 frame without any modifications. Just make sure you have matching LB80 carb going with the engine. No need to modify pedals.

You can use the LB50 stock pipe as I believe they are the same as what was on the LB80. Aftermarket pipe will probably need new jetting. Start with stock working correctly and go from there.

Look up JT sprockets online. They will have stock sprocket set up - front and rear, plus they sell them too.

Good luck!

Eric

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

Eric,

I appreciate your shared knowledge! I would want to remove the LB50 pedals because of the bicycle look, weld on actual foot pegs or foot rest like the LB80.

I have attached pictures of the two close to street ready Chappys. Blue is LB80 & the Red is the LB50.

Many thanks for everyone's help!

-Michael

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20190417_115508.jpg

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

Eric Migliorino /

Welding should be a last resort. Yamaha still sells the foot pegs and treatland sells an MLM foot peg. Note, I’m not sure if the MLM foot pegs work with the stock exhaust and not sure if the MLM exhaust works with stock foot pegs. I have both MLM pegs and pipe brand new but haven’t tried putting them on. Let me check and get back to you. Rockymountainatvmc carries Yamaha OEM parts and is usually one of the least expensive vendors.

Eric

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

Awesome news! Thanks Eric, I'll keep that in mind since I have 3 of these LB50s. The red one being in the best of shape.

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

Eric Migliorino /

Looking at Jack’s LB80, the MLM pipe will work with stock foot pegs. As for the MLM foot pegs, they will NOT work with the stock exhaust. I tried myself last night and it will not clear the header pipe. As for the MLM pipe, I have to assume it’s compatible with the MLM foot pegs. If it were me, I’d go with stock foot pegs although they cost a little more, but if you are going with the MLM pipe and want the MLM foot pegs, I don’t see why not.

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

Can confirm that my stock foot pegs fit with the MLM pipe on my LB80

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

Eric Migliorino /

Check out Jack’s yellow chappy on page 6. It has the MLM pipe and front rack. It also has stock pegs. Note the stock pegs have a big dip toward the clutch side (opposite of shifter side) to accommodate the stock header as well as the MLM pipe.

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

Jack Rutherford /

I'll try to add some more pics

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

Dirty30 Dillon /

After trying every combo of spring in the Chappy clutches, I am pretty frustrated.

No matter how stiff the spring I put in there is, I barely see an increase in stall. Combined with pipe, kit and carb, it means I have port stalling at low rpms which kinda makes the bike unfun.

I'm planning to swap out the LB50 motor with a PW80 motor because why not

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

Eric Migliorino /

Keep us posted on how the pw80 install goes. Others have done it, so it is possible. You may want to play with the gearing/ sprockets if you want to stay with the original chappy engine. The issue you need to understand is that being only a two speed, you need one gear to get it going with lots of torque, then another to get it to top speed with nothing in between to get it there. That big spread in transition will cause that dip when going into 2nd gear. Aside from the pw80 option, changing sprockets for more torque will help but you may sacrifice top speed. Good luck and keep us posted on the pw80 option.

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

Dirty30 Dillon /

> Eric Migliorino Wrote:

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

> Keep us posted on how the pw80 install goes. Others have done it, so it

> is possible. You may want to play with the gearing/ sprockets if you

> want to stay with the original chappy engine. The issue you need to

> understand is that being only a two speed, you need one gear to get it

> going with lots of torque, then another to get it to top speed with

> nothing in between to get it there. That big spread in transition will

> cause that dip when going into 2nd gear. Aside from the pw80 option,

> changing sprockets for more torque will help but you may sacrifice top

> speed. Good luck and keep us posted on the pw80 option.

Yeah, my issue was not top speed with the current setup, nor was it falling off the pipe when I shifted. It was take off from a dead stop. I have had great luck tuning ZA50's but this one just won't slip first to get out of the stall and into the power.

Another thing I notice about the chappy is the over-complication of the transmission. First gear has a one way bearing, the second gear main gear has a free wheel pawl, etc. Rather than over exert on my bottom end, I will build a bottom end that will do what I need and get my good bottom end over to someone who maybe needs it.

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

Eric Migliorino /

Not sure I understand the problem but it sounds like an issue with the carburetor. Sounds like the pilot jet is off. Does it bog when and at what point? Think about how the chappy engine operates. At idle the first gear clutch spins for inside the basket. As you twist the throttle, the 1st gear clutch spreads in the drum and only as RPMs increase does second gear clutch engage as the spring is stronger holding it closed. You probably already know all of this but sometimes it takes breaking things down to figure out the problem. Do you still have the stock carburetor? If that works, maybe it’s a carburetor issue? Maybe the bigger carburetor is too much, meaning the RPM’s jump too quickly and skips right to second gear. Does the bike idle okay in gear?

I know I’m troubleshooting the LB50 engine, but am really rooting for the pw80 conversion. If we could come up with a standard way of conversion, that would work best since pw80 parts are much easier to get. The issues I see are the exhaust, carburetor placement and a little finagling with engine mounts.

Good luck in whatever endeavor you choose.

Eric

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

Dirty30 Dillon /

Definitely not a carburetor tuning issue.

Is the VM20 too big? For low rpm load-up? Yes. Hence my issues. But once it's not stalling the ports, it really really hums well.

That said, I am going to have to do a tear down on this pw80 motor prior to installation, so my update may be delayed.

Also, I have like 20 other projects ongoing. Next thing is selling my boring MB5 and finishing my Vespino.

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

You have peaked my interest with the MB5. I'm in the market for one

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

Dirty30 Dillon /

> Hunter Skiff Wrote:

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

> You have peaked my interest with the MB5. I'm in the market for one

Come grab it from me in Brooklyn, $1000 walks away with a running, driving, ready to go MB5.

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

I'm a little south of Brooklyn here in south florida. However I'll be in NC in July for a wedding and could make the hike the rest of the way to pick it up if its still around 0_o. $1000 is a no brainer

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

Dirty30 Dillon /

> Hunter Skiff Wrote:

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

> I'm a little south of Brooklyn here in south florida. However I'll be in

> NC in July for a wedding and could make the hike the rest of the way to

> pick it up if its still around 0_o. $1000 is a no brainer

I'll keep that in mind. I will honestly be surprised if it lasts that long, but keep me in the loop.

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

Trust me I won't forget and will keep you updated. Ive been looking for one for months now. Seems my neck of the woods is a void for MB5s

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

Eric Migliorino /

Wow you have more projects than me!!!

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

Dirty30 Dillon /

I am a perpetual project maker, very seldom project finisher. I actually think I have 14 bike/projects right now, not including the 8 or so Brooklyn Moped Supply bikes that are getting readied for sale.

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

Jack Rutherford /

Man, I couldn't sleep at night with 14 simultaneous projects. I have 9 bikes and if anything goes wrong with any of them, I'm on it. I gots to get it done.

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

shayne zroback /

Need help. Replaced the points and condensers, set the gap and now no spark. I do have continuity at all three wires coming out of the flywheel now. Not sure what i did wrong.

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

Eric Migliorino /

1. Why did you replace the points and condenser? Points I could see if they were no longer in spec but condensers rarely do go bad.

2. Check your ignition coil. See if there is any resistance readings. Could also be as simple as a bad spark plug. Start with the simple stuff first.

Let us know how it goes.

Eric

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

shayne zroback /

So the condenser was dented and would die under load at full throttle (i believe)The points were very pitted when i got it. I reassembled the stator like it was, then nothing. Check spark plug, good, check spark plug boot, good. Check ignition coil, it was good. Check all connections, they were good. I had a lb80 stator and put it in and kept everything else the same and it fires up. I wonder if the ignition coil on the stator is bad or if i miss wored something. Does anyone have a step by step instructions for wiring that assembly? Thanks

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

Eric Migliorino /

Windings are probably bad. Maybe the coating degraded or got damaged? Not sure how you dented the condenser? Maybe damaged the winding in the process or it got corroded? The winding on the left is probably your issue. I’ve attached how to test resistance. Good luck.

Eric

8199D03E-0CE5-4D78-ABD4-0920E5541268.jpeg

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

shayne zroback /

The condenser was dented before i got to it. Thanks for the info!! I really appreciate it. I will check it tomorrow and see whats the reading tell me..

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

Last night I spent the evening swapping engines on my 79 chappy, took the oem engine off and swapped in one that I just built. Polini 70cc kit with Puch 45mm high comp oring head, VM20 carb with 180 main jet. MLM VM20 intake, MLM Scorpion exhaust, vforce 8 petal reed block for minarelli AM6 ++ puch gilardoni, HPI CDI ignition and an air cleaner from amazon. Plug is B8HS, with head temp gauge, I haven't exceeded 330F. Ignition timing is set 2mm from tdc. Top dead seems to be 27.6mm as measured with verniers through the spark plug hole, I then set the cdi rotor to 29.6mm btdc and zero'd the stator plate to that, I advanced the timing a bit and the bike did not like that at all.

Currently it has a very odd sound coming from the engine, almost as if there are worn bearings, it's a loud whirring type sound. The Chappy is kind of slow to take off but begins to pull really hard up above 20 in drive. In low gear it's got much more grunt and really shifts hard into second at which point I usually shift it into drive. I'm thinking that there are some broken gears inside as it skips from time to time and it's an abrupt skip. I didn't split the case but it looked clean through the oil fill hole. I had a second spare engine that was locked up solid, rusted was an understatement, even a hammer could not move the piston on the rod or the rod on the crank.

Has anyone else had experience tuning the VM20 carb on the chappy? I've done a fair bit of searching and didn't see anything. Also, anyone had broken gears inside the case? Does what i'm experiencing make sense?

Thanks and Cheers!

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

Dirty30 Dillon /

> Robin D'Agostino Wrote:

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

> Last night I spent the evening swapping engines on my 79 chappy, took

> the oem engine off and swapped in one that I just built. Polini 70cc

> kit with Puch 45mm high comp oring head, VM20 carb with 180 main jet.

> MLM VM20 intake, MLM Scorpion exhaust, vforce 8 petal reed block for

> minarelli AM6 ++ puch gilardoni, HPI CDI ignition and an air cleaner

> from amazon. Plug is B8HS, with head temp gauge, I haven't exceeded

> 330F. Ignition timing is set 2mm from tdc. Top dead seems to be 27.6mm

> as measured with verniers through the spark plug hole, I then set the

> cdi rotor to 29.6mm btdc and zero'd the stator plate to that, I advanced

> the timing a bit and the bike did not like that at all.

>

> Currently it has a very odd sound coming from the engine, almost as if

> if there are worn bearings, it's a loud whirring type sound. The Chappy

> is kind of slow to take off but begins to pull really hard up above 20

> in drive. In low gear it's got much more grunt and really shifts hard

> into second at which point I usually shift it into drive. I'm thinking

> that there are some broken gears inside as it skips from time to time

> and it's an abrupt skip. I didn't split the case but it looked clean

> through the oil fill hole. I had a second spare engine that was locked

> up solid, rusted was an understatement, even a hammer could not move the

> piston on the rod or the rod on the crank.

>

> Has anyone else had experience tuning the VM20 carb on the chappy? I've

> done a fair bit of searching and didn't see anything. Also, anyone had

> broken gears inside the case? Does what i'm experiencing make sense?

>

>

>

> Thanks and Cheers!

Your sluggish takeoff is very similar to my own issues. I have a Polini/VM20/Polini Pipe and port stall is pretty significant. The only way I figured to overcome this was to rev unloaded into the powerband (i.e. clutch springs) but I have had no luck in this. You temps sound good, but I am only working with the stock Points.

The skip is most assuredly from the second gear one-way pawls which are a common failure point it seems, especially with higher HP output. Once these go, I think the only option is to have the center hub welded to the pawl, but I am not even sure if that is totally feasible.

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

Eric Migliorino /

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?

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