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

Do you know if they fit under the stock plastic panel? If they do, something like a 16.16 with the angled choke and throttle pieces might be a solution down the road.

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

Dirty30 Dillon /

> Hunter Skiff Wrote:

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

> Do you know if they fit under the stock plastic panel? If they do,

> something like a 16.16 with the angled choke and throttle pieces might

> be a solution down the road.

No Idea, I've never had the top plastic for my Chappy.

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

Jack Rutherford /

just for giggles and not that it will help, a qt50 carb fits perfectly on the lb80 intake but the plastic cover probably won't fit over it. Yes bottom end suffers on the lb80 with mlm pipe. I've debated about how to address it - probably different sprockets or change the jetting.

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

Update: Installed the Polini Kit on my LB50 this weekend. Stock carb up-jetted from 70 to 82. Sustained wide-open temperatures 310-320*F. Bike still is in the break in period so im taking it easy. Performance gains seem minimal at this point with just the big bore kit. Also cut open the stock muffler and drilled some holes in the meshed divider between the two separate "chambers." Also removed the spark arrestor. Modifications to the pipe seem to have made significant power improvements. Bike now has a noticeable "power band." Bike starts pulling at 17mph and continues to 28-30mph (top speed). Will keep updating here as I tweak and tune the bike during and after the break in process. I now understand why Dillon was so interested in moving the 1-2 shift higher in the rpm range. Unlike the LB80 which shifts at ~ 20mph, the LB50 consistently shifts at 10mph,. and when it does so falls completely on its face. God forbid you're trying to accelerate up a hill.

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

Jack Rutherford /

Nice work and those are some cool temps!

chappys.jpg

My friend bought two Chappys. One is a parts bike. So stator and related items are on the way to me to fix his original Chappy. Of course, none of his 3 Chappys has a headlight. He's looking to sell the red Chappy that runs above. Located in Northeast Ohio, fyi.

Anybody have any replacement headlight recommendations? I think I need a bezel as well. I found this on ebay. (edited)

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

Thats a gaggle of Chappys!!

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

Jack Rutherford /

yeah, he's kind of quick on the trigger

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

LB50 Upgrade Update: Thanks to a local motorcycle shop that specialized in Chappy's we were able to modify the bike to look and ride more like an LB80.

-Polini kit added

-MLM stand with side peg (Put rubbed over pegs)

-Keep the mount stand as well

-Removed bicycle pedals

-Added LB80 starter lever

-modified carb cover by heating and reforming the plastic

-removed extra chain attached for old bicycle pedals

-Added a lithium battery

Electronics all work, except the speedometer doesn't feel like it's 100% accurate.

Reading previous posts regarding the shift change with LB50s at 10mph vs LB80s @ 15mph and that did come up in conversation with the shop as we thought it was acting up not knowing that LB50s are suppose to shift at 10mph.

I didn't change the sprockets, would need what to make that happen?

Stock exhaust, not modified.

Chappy can eventually get up to 30mph now with me driving at 185lbs weight.

20190601_105359.jpg
20190601_105408.jpg
20190601_105454.jpg

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

Dirty30 Dillon /

The shift point on my bike is more around 15-ish, with the polini kit and matched polini pipe.

The problem for me is more so on the first gear engagement. It engages so low from take off when I want REAL clutch stall. I am happily getting 35 mph on flat ground but my 0-5 acceleration is shit. from 5-35 I am good.

Once I knock out a few other project on the bench, I will bring the PW80 motor i to make an intake and get it mounted up.

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

Eric Migliorino /

Seems the zero to 5 not working properly is like you are starting in second gear and the bike just can’t handle the starting from a dead stop because you are in too high of a gear. The LB50 typically acts as if it’s a 3 speed but missing second gear. Maybe try removing the second gear clutch and see if you get the first gear does the same thing. You probably will need to stack washers or put a spacer in for mission second year clutch.

BTW, I’m excited for the LB80 conversion!

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

Eric Migliorino /

I’ve recently did similar upgrades and have my son’s LB50 doing 35mph on the flats with my fat butt. I did some videos that I’ll need to post of my upgrades. Set up as follows:

- Polini 70cc kit with stock reed valve.

- Head is currently stock, even though I have the high compression head and “hi hi” compression from Treats. Will post gains if any from both.

- Compression stayed roughly the same between stock cylinder and head. Chappy’s were designed with low compression making it easier for petite women in Japan to kick over this little bike. Compression was roughly in the 90’s, which on any other bike would be low.

- Stock NGK B6HS plug with stock gap.

- Stock Sprockets - believe 32 tooth in the rear and I think either 12 or 13 tooth up front.

- MLM People’s pipe.

- LB80 carburetor with stock air filter. Carburetor is older style Carburetor used 1976 LB80 or older.

- I had to change the main jet from a 65 to 95 main jet. Pilot jet and clip on jet need kept at stock settings. Air screw, I had to do about 1 to 1 1/4 turns out vs. stock 1 1/2 turns out. Note being in Jersey, I’m basically at sea level.

- Installed LB80 oil pump. Checked plunger movement with dial gauge to insure within spec.

- Regular pump gas.

With upgrades, still not as powerful as LB80, but note, piston size difference still somewhat substantial between Polini kit and LB80. Does take off pretty quick up to about 10mph, but pick up falls off once you shift to second gear. Bike pulls ahead strong once you hit 20/25 mph. Feels like bike is 3 speed but missing 2nd gear causing sluggish transition to 2nd. Hope upping compression with Treats heads will help this issue. (Note you need to change cylinder studs to accommodate Treats heads. I used stainless steel threaded rod and cut to size. Also hope this adds a few MPH. If it tops out close to 40mph, we’ll call it good. May play with gearing once I get set with Treats heads. Goal was to make Chappy somewhat fast, but keep stock reliability and looks. Also wanted to keep oil pump for convenience, plus the pump makes sense to me - little oil at low rpms and add more when it’s pegged.

Also note, I tried using the stock carb with the MLM pipe and Polini kit, but the bike struggled and got slower than stock.

Polini kit is solid and manufactured as well as stock Yamaha parts. I probably will try similar setup on another LB50 I own, but will try PW80 carb matched with PW80 oil pump, since LB80 carbs are hard to come by. Don’t know if I will order OEM Mikuni or get Chinese clone off rockymountainatvmc. PW80 carb comes with 120 main jet so will match with LB80 oil pump. I really like the MLM pipe but it is a bit pricey. Quality is as good as an OEM pipe but fitment is okay, but not perfect. Sits against swing arm and you lose the Chappy badging. Stock pipe is #1 restriction. I have a stock pipe that was modified by someone opening up the muffler, removing baffles, welding it shut and removing spark arrestor. Performance is similar to MLM, but is just flat out obnoxiously loud (louder than MLM by at least 30%) and doesn’t sound anywhere as nice and throaty. But again the MLM pipe is somewhat pricey unless you buy it during a Treats sale. Probably worth getting, and absolutely necessary if you don’t weld.

Sorry it’s long but wanted to be thorough. Hope this helps others and saves some time having to research a bike that has little information out there.

Eric

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

Eric Migliorino /

I also didn’t case match to the cylinder in case I need to switch back to 49cc cylinder. Regarding the PW80 carb, I want to match with PW80 oil pump, not LB80 oil pump, although either will most likely work. Need to look up output levels and see if close.

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

Eric,

No need to apologize on the length & details. I appreciate your informative post, that will save me a lot of headaches going forward with my LB50 converted and my 2nd LB50 that I'm looking to upgrade. It has been difficult to get maximum performance while keeping the original Chappy look.

Looking forward to those videos!

Thank you,

-Michael

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

Dirty30 Dillon /

> Eric Migliorino Wrote:

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

> Seems the zero to 5 not working properly is like you are starting in

> second gear and the bike just can’t handle the starting from a dead stop

> because you are in too high of a gear.

That's not the issue, I am getting a full, healthy shift to second and experiencing no bog between the two gears as described below. The reeds, transfers, and exhaust are all capable of REALLY great flow at RPM, but when you slam the throttle of the VM20 you increase volume way too fast and your mixture velocity plummets, causing port stall.

As stated, if there were a way to successfully raise the spring tension in the clutch, this would be a winner. But alas, I have tried numerous springs and after hours of struggling to try and install a 100cc chainsaw spring (which on that saw doesn;t grab until like 5k) I just haven't seen enough improvement, hence the PW80 conversion.

> The LB50 typically acts as if

> it’s a 3 speed but missing second gear. Maybe try removing the second

> gear clutch and see if you get the first gear does the same thing. You

> probably will need to stack washers or put a spacer in for mission

> second year clutch.

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

Eric Migliorino /

Yeah the chappy bottom end design probably can’t that influx of power, hence stumbling on itself. Your last option would be to swap internal gearing from an LB80, which obviously differs from an LB50. I’m not thinking the gears would be interchangeable, but maybe not. At this point, I’d stop farting around with the LB50 engine and just sink your time into the PW80 swap. 12 volt electrical system and soooooo much better part availability and upgrades, it’s a no brainer!

Take a look around the site, there are people who have successfully did the PW80 swap. Just search “chappy“ and a blue one comes up. I can see the carb and the manifold has the carb facing out front, just over the cylinder. Maybe he extended the manifold? The one thing I wanted to see was the exhaust, but picture is wrong side. Challenges I see are carb clearing frame, exhaust fabrication and mounting engine on frame with sprockets lines up. Wiring up 12v system may be a challenge too and all bulbs would likely need to be changed.

Good luck and keep us posted!

Eric

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

Jack Rutherford /

Does anyone have a wiring diagram for US model Chappy. Project moped manual has wiring schemes for France, Sweden, Denmark, Germany, etc., but no U.S.A.

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

Dirty30 Dillon /
Capture.JPG

Yep

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

Jack Rutherford /

thanks. Didn't know they made CDI Chappys. Learn something new. Mine is a points ignition. My buddy sent me the stator off an lb50 to put on this lb80. Problem is - it is missing the green wire coming out of the stator.

IMG_6245copy.jpg

So here is the wiring coming out of the bike. I don't have a green wire coming out of the stator to connect to this. I'm assuming green is ground but could be wrong. Is there any way for me to add a ground wire to the stator, if so, how. Or does the stator ground to the chassis somehow? I'm not getting spark either, of course.

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

Jack Rutherford /

So fuel cap dilemma may be solved. They had at least two different gas caps for these things.

Here's one that I need:

octagoncap.jpg

See how it has 8 sides.

Here's one that doesn't work for me although advertised for a 1976 Chappy:

othercap.jpg

This is also the same gas cap as the Towny.

I've also seen this one advertised for the Chappy which looks just like the qt50 gas

cap.

othergas2.jpg

(edited)

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

Eric Migliorino /

I believe the round plastic cap is for newer chappy’s. Probably ‘77 or ‘78 and later. The point cap is probably ‘76 and earlier. The metal cap is probably for the LB80 Champ, but who knows?

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

Eric Migliorino /

LB80 and LB50 wire diagrams.

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

Eric Migliorino /

LB80 stator will have either 591 or 1F7 printed on the back and will have 4 wires. I assume the extra wire is the ground. See electrical schematics I posted earlier. LB50 will have 2U7 stamped on the back and only has three wires leading into a plug. I believe the LB50 stator grounds to the case. Again refer to the electrical schematics I posted earlier. Have pictures of the stators too.

033E83E7-4DAC-4B75-86E5-E6F1E6AB820A.jpeg
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Re: The Official Yamaha Chappy (LB50) Thread!!!

Eric Migliorino /

LB50 stator and plug. Note only 3 wires.

CC0363BA-7F81-457D-95B3-7B88B379485F.jpeg

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

Jack Rutherford /

Thank you that was very helpful. The extra stator I have is from an lb50. Can I make that work on an lb80 by adding a ground wire or grounding it to the case? Any ideas on how to do that? Or how does the lb50 stator ground to the case.

I'm going to pull my lb80 stator off my Chappy and put it on my friend's lb80 and see if I can get it to start.

I've been browsing ebay and found what looks to be a 5 wire stator although I can't tell for sure:

5wire.jpg

and what appears to be a 6 wire stator:

6wire.jpg

now I'm gun-shy to buy any ebay stator (edited)

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

Jack Rutherford /

Ok, after looking at both those wiring diagrams - both the 50 and the 80 appear to use Black wire for grounding. The green wire looks like it runs to the main switch on the 80. I've been messing with Honda wiring too much where I believe green is ground.

Anyhow, I may just have to find the right stator. Not sure if the 50 stator can be made to work.

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

Jack Rutherford /

alright the I love Japan motors stator is 4 wires.

and the "6 wire" stator is off a champ 80 (edited)

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

Eric Migliorino /

Remember the LB80 has 3 position switch for your key whereas the LB50 has a two position switch. The LB80 you can choose to have the lights on whereas the LB50 they are on if the switch is turned on. Also remember one is the coils is just for powering lightning. That’s probably why you have the extra wire on the LB80, choose whether or not you want power to the lights.

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

Eric Migliorino /

Prices seem really high for a stator on fleabay. I know it’s a lot more, but they do sell a CDI conversion on Treats. No more points and you probably will have the ability to advance or retard timing. 12 volt solid state system!

Otherwise make the LB50 stator work. I’m sure it’s possible. Just compare the schematics.

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

Jack Rutherford /

Well, I'm working on a friend's Chappy. I don't think he's going to shell out for that HPI system. And to further confuse the issue. I wrote the seller of that 4 wire stator and asked him what the green wire was for.

s-l1600.jpg

His response: "hello .

the green wire is for neutral gear ( for chappy 3speed - 4speed only )

if yours chappy is automatic , you don't connected anywhere .

thanks"

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

Dirty30 Dillon /

> Jack Rutherford Wrote:

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

> His response: "hello .

>

> the green wire is for neutral gear ( for chappy 3speed - 4speed only )

>

> if yours chappy is automatic , you don't connected anywhere .

>

> thanks"

That makes sense. It's the ground for the Neutral Indicator Light. Just ignore it.

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