Re: Yamaha Champ LC50

Jack Rutherford /

your carb just needs a thorough cleaning

Re: Yamaha Champ LC50

Hey guys,

For anyone who has one of these in 2019 I wanted to add my 2 cents.

Many engine parts from a QT50 will fit the engine of the LC50 Champ, but both bikes are getting more rare and parts fewer and fewer. The engine is also largely the same as a PW50 dirtbike which has massive aftermarket support. I ordered from PWonly.com I got a 21MM carb, and an oil injection block off plug. the carb has the choke built on top of it so no need to get the QT50 hand controls and run a choke cable up. For my big bore I bought the Niche Industries 60CC kit, it came with new studs rings and everything for under $50 for a PW50. The carb kit came with a 21mm carb, performance reed valves pod intake filter etc.. but I did have to cut the intake and clock it to fit between the frame of the LC50. I used a hack saw and JB weld and its holding just fine... (its aluminum and I don't have equipment to weld it).

When you go big bore you lose the vacuum line out of the head. that means the auto choke on the carb will no longer work, but, that also means you can delete the bi-metal valve and all those hoses on top of the engine (Good if you BMV is broken) . The fuel petcock is also vacuum operated so you will have to swap that out as well when you go big bore. I ordered a PW50 petcock and built a frame mount for it. where the original vacuum operated one sat. I also had the engine ripped down so I deleted the oil injection to free up more power. While I had the engine open I port matchedcase ports to the head and flowed the case out lightly.

The final result is a way cleaner setup no vacuum lines everywhere etc... no cable splitter for the oil injection...(I used a throttle cable from a Ruckus I had laying around) no oil injection pump etc... the list goes on.

I also did a handlebar wire-tuck and blacked out a few components on mine. I will upload pictures when I get a chance.

Re: Yamaha Champ LC50

Great information! Anyone have a diagram of the auto choke petcock? I disassembled mine and dropped a copper washer (behind the leaver attachment ring) I tore my garage apart looking for it, but it fell into another dimension!! I am hoping it was a non stock attempt to tighten the attachment ring. I soaked the gasket in two stroke oil and used oil of wintergreen and alcohol on the rubber seal. So these items, dry for 25 years swelled back up a bit. I am hoping the copper "washer" may not be needed but any information would be greatly appreciated !

Re: Yamaha Champ LC50

I always sort of wondered about the nomenclature of the "LC50" designation. I mean the "50" I assume was the CC displacement (well 49 if your being technical) but the "LC"?...Then I had an epiphany...

Re: Yamaha Champ LC50

"Little Chief"...

IMG_20191025_132259.jpg

Re: Yamaha Champ LC50

Kind of a pretty little thing .

Does it play drummer tunes when you ride it ? ;)

Re: Yamaha Champ LC50

About the coked out kids at Yamaha, I doubt that in Japan if you get caught they kill your first born son in front of you then your mother then you. They just had too much sake

Re: Yamaha Champ LC50

The LC stands for Lots of Cocaine.

I had a question for you LC 50 Gurus. My bike sat out in the weather for 7 years. It has been fully rebuilt from the ground up. I have a very few things left to do on it.

My drum brake housing built into the rims rusted out and the diameter is too large for the brake shoes. Has anyone else had this issue ?

I am considering a disc brake conversion The front wouldn't be too bad but the rear wouldbe a huge struggle.

But I have been wondering if the 3 spoke PW50 dirt bike wheels could be used in place. Has anyone measured this or done this ? Thanks.(edited)

Re: Yamaha Champ LC50

is the drum still round, just hogged out?

you might be able to make a small shim for the fulcrum (ie non cam) side to increase the working diameter.

Re: Yamaha Champ LC50

Yeah it seems round and in decently good condition but quite hogged out. I like your idea though. It looks like the PW50 uses a different size brake shoe but I haven't been able to verify this for sure. I was thinking of welding a strip of metal into the drum to reduce the diameter.

I am doing a restomod on my Champ and have upgraded a number of components for more preformance. The brakes on these things are pretty weak to begin with so I am not opposed to upgrades.

The Riva Razz and Jog ch and jog cy models all have a 10 x 2.15 Rims that should fit. The front rim has the 10mm axle bolt. The rear rim has the 16 spline shaft as well. The same as the Champ. The brake shoe part numbers are the same for a number of the models as well. I am still trying to double check all this.

I am thinking the Jog R rims would be an awesome upgrade as they would provide a front disc mount. And all I would need to do is weld a caliper mount to the shock tube.

I need to find someone with a jog and test my theory. Sadly I am in a very isolated part and have almost no way to test this.

Re: Yamaha Champ LC50

Maybe mine is an outlier but the brakes on my champ are some of the best drums I've ever felt. They'll both lock up pretty easily at any speed.

Re: Yamaha Champ LC50

Drexler Cayabyab /

> Ree Zygn Wrote:

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

> Hey guys,

>

> For anyone who has one of these in 2019 I wanted to add my 2 cents.

>

> Many engine parts from a QT50 will fit the engine of the LC50 Champ, but

> both bikes are getting more rare and parts fewer and fewer. The engine

> is also largely the same as a PW50 dirtbike which has massive

> aftermarket support. I ordered from PWonly.com I got a 21MM carb, and an

> oil injection block off plug. the carb has the choke built on top of it

> so no need to get the QT50 hand controls and run a choke cable up. For

> my big bore I bought the Niche Industries 60CC kit, it came with new

> studs rings and everything for under $50 for a PW50. The carb kit came

> with a 21mm carb, performance reed valves pod intake filter etc.. but

> I did have to cut the intake and clock it to fit between the frame of

> the LC50. I used a hack saw and JB weld and its holding just fine...

> (its aluminum and I don't have equipment to weld it).

>

> When you go big bore you lose the vacuum line out of the head. that

> means the auto choke on the carb will no longer work, but, that also

> means you can delete the bi-metal valve and all those hoses on top of

> the engine (Good if you BMV is broken) . The fuel petcock is also vacuum

> operated so you will have to swap that out as well when you go big bore.

> I ordered a PW50 petcock and built a frame mount for it. where the

> original vacuum operated one sat. I also had the engine ripped down so I

> deleted the oil injection to free up more power. While I had the engine

> open I port matchedcase ports to the head and flowed the case out

> lightly.

>

> The final result is a way cleaner setup no vacuum lines everywhere

> etc... no cable splitter for the oil injection...(I used a throttle

> cable from a Ruckus I had laying around) no oil injection pump etc...

> the list goes on.

>

> I also did a handlebar wire-tuck and blacked out a few components on

> mine. I will upload pictures when I get a chance.

This is an interesting.

I've got a good deal I've managed to get 2 yamaha LC 50 champ and I'm planning on restoring/rebuilding them out or making a project bike and turning it as a mini cafe racer.

My problem is the engine itself since it has been left untouched for nearly 13years, was left to rot and exposed to different nature elements and definitely it will be needing some new parts for it and I've been searching for the net for ages to find a possible parts for it or any alternative top and lower engine parts that is entirely interchangeable to use, I've seen your post and it got my attention right away.

Can you drop all the pw50 engine parts that can be used for the champ? It would help me a lot of and save me from a year long headache if you can drop all the pw50 engine parts that can be interchangeable with the champ engines so that I can start ordering things out and start with my restoration project?

Cheeers!!!

Re: Yamaha Champ LC50

Hi, guys I just got myself a 1981 Yamaha Champ , has very weak spark . Any help where to start ? I check the grounds, wire harness , coil , new spark plug . Only one thing I found not rite is magneto and stator looks like the were rubbing each other.

4B428BB3-8210-45E0-A5BF-1271630FF247.jpeg
C6B54721-00C7-44D0-93E2-91AEB9274A72.jpeg

Re: Yamaha Champ LC50

> Alex G Wrote:

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

>Only one thing I found not rite is magneto and stator looks

> like the were rubbing each other.

That would do it .

Clean the magnets and sand any high spots down .

File the coil core ends flush .

Mount the flywheel and check coil core end to magnet clearance .

Closer the better , without touching .

Re: Yamaha Champ LC50

what are the best tires to get for this little guy.

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