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

Eric Migliorino /

Maybe with the shaft sticking out that far, the regular kicker will clear your pedals from the pw80?

Also the kicker from the chappy looks very similar to a pw80 but obviously shorter. If the gears on the end of the kick start shaft are the same between the two, maybe you can use the chappy kick start shaft and LB50 kicker?

I’m glad you are doing this project and sharing what works/doesn’t work. Keep us posted!

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

Dirty30 Dillon /

The actual trans side cover and case are different between the two motors, meaning the kick shaft length is different to protrude equally, if that makes sense.

You MIGHT be able to make something work, but honestly I doubt that this motor will need more than a short kick to fire up. If it turns out otherwise, I am definitely not opposed to building some pegs for this as well.

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

Hey all - Just wanted to introduce myself. My inlaws have had an LB50 (was my wife’s grandpa’s) at their place for many years. They live on a lake and I would fire it up every time I was up there and take my kids for a spin around the lake. I was always so amazed at the thing - it sat for 10 years idle after my wife’s grandpa passed, and every time I get on it, the bloody thing starts right up after a few kicks. Anyway - I am the only one that ever rode it, so they gave it to me as a 40th birthday present last week. Just wanted to say hi and thanks for the good reads, I hope to do some restoration on it in the future.

And I concur- mine will do about 23-25 with me (190#) and a 4 year old on it.

5DFAD49C-1280-4A95-AEF6-08F33A1FD0F0.jpeg

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

Nice birthday present .

They must not like you very much , to off load such a pain on you . ;)

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

Jack Rutherford /

Wish my lb50 was as nice. Anybody holding a cylinder and head?

C0DEB22A-FDAD-43AB-88B0-64C2E758F7D4.jpeg

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

Jack Rutherford /

Chappy conversion

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

Eric Migliorino /

That chappy is mint! Good luck with it! Any questions, just ask.

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

Eric Migliorino /

Good luck with building your unicorn!

I’m trying to build my own unicorn too but mine is an auto clutch 3 speed from an LB80 Champ.

Where did you find your unicorn horn?

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

Jack Rutherford /

My buddy in Missouri. Exhaust and foot pegs to arrive Wednesday. Also building lb50 frame with lb80 engine.

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

Jack Rutherford /
E2C0F7B0-0A80-44C6-A132-47CA53BD08D3.jpeg

Just worked out the foot pegs, rear brake lever, exhaust on this side. Took it for a short ride tonight pretty cool. 1st thru 4th are all up with neutral on the bottom.

Had a lot of low end so I can probably change the sprockets and gain some top end.

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

I am eternally jealous of your 4-speed

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

Jack Rutherford /

My buddy in Missouri has stumbled onto two of them. I got the engine and other stuff from him. He traded his other one. I’ll tell him to keep an eye out for another. I’ve seen one for sale in Ohio but seller wanted $1400.

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

Eric Migliorino /

Does it everyone have the same issue I have? Every engine, either LB50 or LB80, they ALL leak oil!!

What I’m suspecting is the breather hole (note there is no actual breather cap or element) on top of the engine. It starts up there and usually makes its way down the back side of the case towards the kickstand.

I’m using Castrol Actevo 10-40, which I use in my four strokes. At first I was using the dipstick to measure how much oil to put in and figured maybe I’m overfilling? So I bought a measuring cup and put in exactly 650cc’s. Although less oil is leaking, it is still leaking!

At first I blamed the seal between the case halves and did a full tear down and put back together using Honda bond to seal the case halves. Still leaked from up top. Tossed in an LB80 engine without messing with it, but only changing the transmission oil, measuring 650cc’s and still it leaks! All the scrap engines I’ve bought, the backside top of the case halves usually have caked on dirt starting there and making its way to the bottom of the engine. I’m really thinking this is a design flaw in these little engines?

Does anyone else experience the same? What oil are you using in the transmission and how much?

My only other thought is I replaced my tires with the Michelin tires Treats sells and they are slightly smaller than stock. I still have the stock LB50 rear sprocket but went up one tooth on the front sprocket to 14T. Again this is an LB80 engine that I had from an LB80 that I didn’t mess with except I have the MLM people’s pipe and I upjetted the stock (older LB80 one float carb) from a 12.5 to 15 pilot jet and upped the 65 main jet to a 95 main jet to accommodate for the extra air flow from derestricting the exhaust. Obviously the chappy’s don’t have a CDI and therefore have no rev limiter. I can get the chappy up to about 40mph on the flats and I have plenty of power to get up hills. Okay, where am I going with this? I’m thinking with the slightly smaller tires and limited regearing that I’m spinning that little tranny way too much and it just throwing oil out that breather hole. I don’t hold at 40mph that long as it feels like that’s all the little engine can take.

Sorry for the long rant, but am I the only one that has oil leaks from the tranny? Does anyone else find oil from the top of the case halves going down the backside of the engine?

Thanks for any input!

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

Dirty30 Dillon /

It's definitely not something I ever ran into, and I was running my chappy @ 36~mph on stock gearing. It was turning at least 9k at overrev and didn't leak a drop.

The 4 speed Chappy motor are sweet and fairly common overseas, but people want a lot for them seeing as all the bikes they came on fit into the Honda Monkey Bike segment of collectors. I deal with imported bikes very frequently and I won't even bother with the hassle of trying to import one.

For the half the cost of the LB50 4speed, you could get an entire PW80 and not have to worry about sourcing foot brakes and shifter stuff.

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

Eric Migliorino /

Dillon, are you using 10W-30?

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

Dirty30 Dillon /

> Eric Migliorino Wrote:

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

> Dillon, are you using 10W-30?

Yep, standard conventional 10W30. Haven't seen a drop of any fluid leak out of the LB50 motor since the day I bought it.

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

Jack Rutherford /

My latest lb80 engine seems to have a small oil leak. I’ve got to track it down but I’m getting oil on the top of the header right near the drain bolt but drain bolt doesn’t seem to be leaking.

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

> Dirty30 Dillon Wrote:

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

> > Eric Migliorino Wrote:

>

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

>

> > Dillon, are you using 10W-30?

>

> Yep, standard conventional 10W30. Haven't seen a drop of any fluid leak

> out of the LB50 motor since the day I bought it.

I’m in the same boat

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

Jack Rutherford /

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

Hi y’all,

Just upgraded my LB80’s carb from Mikuni VM16 to a Dellorto PHBG 17mm. I’ll be using a shim to fit the carb on the intake and using a Malossi PHBG E12 filter. Any suggestions on what jets I should be running? From Treats it will arrive with 50 idle jet, 60 starter jet, and 78 main jet... Everything else on the bike is stock.

Cheers

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

Jack Rutherford /

this pw80 clone carb is killing me. It still dumps gas as if the float needle is blocked. I've cleaned it numerous times and am running a paper filter.

I assume one of these ports is oil injection. What's the other?

pw80carb.jpg
pw80carb2.jpg

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

The second one is most likely the oil barb since it is behind the Venturi and under "vacuum"

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

Jack Rutherford /

Thanks. Maybe I just need to adjust the float.

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

possibly bad needle or seat?

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

Jack ,

The first pic shows the barb for a vent hose , according to this manual :

https://library.ymcapps.net/library/om/contents/pdf/10/3RV-28199-8G_02.pdf

That hose should be route away and left open to the atmosphere .

Have you insured that the needle is seating properly in the float valve seat ?

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

Jack Rutherford /

I might have capped that. I'll check.

> P D Wrote:

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

> Jack ,

>

> The first pic shows the barb for a vent hose , according to this manual

> :

>

> https://library.ymcapps.net/library/om/contents/pdf/10/3RV-28199-8G_02.pdf

>

> That hose should be route away and left open to the atmosphere .

>

> Have you insured that the needle is seating properly in the float valve

> seat ?

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

Jack Rutherford /

I’ll check the needle and seat as well. Thanks

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

Jack Rutherford /

Ok, got tired of messing with the pw80 clone carb and already had a vm20 laying around collecting dust. So out the mother-honkin' door the clone carb went. Well not really just figuratively.

Now we gots vm20 with adjustable jet. Kind of neat to be able to adjust the jet on the fly at full throttle. Gives you some immediate feedback that you can't get otherwise.

vm20chappy.jpg

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

Please report back on your findings. The VM20s have always been a breeze to tune. Wouldn't mind cutting up a plastic cover if the performance was there.

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

Jack Rutherford /

will do. I'm waiting on a rear brake cable and have a bunch of wiring to do still and the exhaust still might be partially clogged. I burned it out but maybe not enough. I've got the stock throttle cable to work with it but it's not perfect. yea yea, the list goes on, right? The vm20 sits so high on that intake that it looks like it is just barely below the bottom of the gas tank. I was initially running too much fuel line and when it started to get low on gas, it started revving like crazy because it was sucking in air and little fuel (I had also got the throttle cable stuck with the slide open - bad combo). I had to pull the spark plug cap off while jamming on the front brake and keeping my feet planted on the ground. I don't have a working kill switch or ignition yet. Even after I pulled the plug it kept revving.

So yeah, I got some things to do before I take it for another ride and this is the engine with the HPI and it's over retarded right now so you get it.

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account