Fixing up a 1981 Yamaha Champ

[Lap202]

Figured I'd post this here since the yamaha forums apparently are useless -.-

Skip to the questions if you're not interested in a read on the life of my champ.

The History
So 4 years ago, the summer between my junior and senior year of high school my mother took away the car due to me being epic. So one day after running 5 miles into town I found a scooter on the side of the road with a for sale sign on it. After talking to the owner, my dumbheaded 17 year old self purchased the LC50G Yamaha Champ for 300 dollars.

The Work I've Done So Far
Starting out the sealed beam headlight was out. At the time I thought it was a bulbed headlight and it be an easy replacement. After discovering it was a sealed beam and none existed on the Internet, I had to improvise.

I used a torch and cut the bulb out of the sealed beam and bent the metal around the glass of the headlight till it could be removed with a flathead screwdriver for easy access to the new bulb. I couldn't find a metal socket that supported the high beam low beam single bulb, so I decided single beam would suffice. I welded the new socket into the sealed beam and bought a new 6v bulb.

Pop. 30 seconds the bulb was fried. 3 burned out bulbs later and a multimeter later revealed the scooter is bushing 13.5 volts. What? Every thing said the bike was a 6v system. The back of the sealed beam also agreed.

After this I went ahead and checked the battery. 6v battery. Plugged it in... fried. So what was wrong? I checked all the electrical at this point. All indicator lights fried, headlight fried, and battery. I finally decided to put it back together and thas when I realised the coil was different from the OEM in the diagrams. A 12v coil.

So at this point I tossed in a 12v bulb. Boom. Working headlight. The rest I decided was fine at the point, the bike produced enough power to run all the electrics at idle. What could go wrong now?

I rode the scooter for 3 months almost issue free until the vacuum petcock went bad leaking gas everywhere. It wasnt repairable and I realized this bike and parts are almost non existent online.

It sat for 3 years and I finally decided this year to work on it. I did a Y off tank and combined res and main into 1 line with an in line shut off valve, which yes from there into the carb and the feed out of the carb.

The champ was back! Or not.

The Problem
Gas poured out the back of the carb. I turned off the gas a bit dissapointed and started kicking. The scooter eventually came to life running like a champ! But as soon as gas was turned on it refloods the carb and it dies.

I have taken apart the carb and cleaned it out. Float isn't stuck and needle seems to be in place but it's still allowing gas in. So problem started after I took vacuum petcock off.

My Questions
1. Would finding any random vacuum petcock work as a replacement?
-I feel like this is a bandaid on a bad carb, but if it works it's a cheap fix.

2. I read online about the PW80 carb fitting on the scooter and working plug and play. Is there anyone that has experience or knowledge of this process?
-Carb would cost 17 dollars and be an easy fix. Also could plug a choke cable into the carb as it has no choke as the bimetal valve (BMV) which chokes based on engine temp was removed.

3. Finally I'd like my high beam switch to actually turn the highbeam on, which means I need to cut out the current socket and solder in like an H4 which is pretty much just a plastic plug for the bulb. Is there a good way to attach it to the metal casing on the headlight?

The Plan
I eventually have big plans for the scooter. The lower is going to be replaced with a pw50 big bore kit to get the extra umph.

Once the scooter us running and no mechanical problems arise, I will start out with placing a 12v battery in place of the 6v battery for the steady electrics. The headlight will receive and h4 bulb which is brighter and has the highbeam on the bulb so I'll have more than just low beams.

Next is the big work. I will be completely disassembling the bike. The frame is getting sanded and filled to remove scratches and dents and painted either a burnt orange or a dark metallic blue. The engine and plastics will get a fresh coat of black paint.

After its back together, the tail lights are beat up and will be replaced. The rest is me being picky about how thing s look and doing small adjustments.

Sorry for the long write up, figured I give you guys some reading material.

[Alex]

[Lap202]

UPDATE
So my leaky carb has been alluding me for weeks and suddenly it hit me. The problem started after I removed the vacuum petcock.. vacuum.. to work it needs a vacuum line. I realized I ran fuel into the vacuum line when I removed the petcock.

I haven't tested yet, but I've melted the end of a hose and will be installing it and running a single line of fuel. If this works, the scooter will be 100% running.

I'm still curious about the PW80 carb, but wnot need it at this moment if I get this carb working.

[RacinNinja]

Float needle is bad or the float level is incorrect. This is not a petcock problem. Please don't think it's vacuum related. Also, down inside the hole the needle goes into may be some corrosion or nastiness built up. Clean it out with a little piece of scotch brite on the end of a screwdriver.

[Lap202]

Haha you are so so wrong and I am so so right :P I tore carb down so I knew it wasn't carburetor. Last night I sealed the vacuum line and ran the fuel to only the fuel intake and we're up and running! Gas was pouring through the vacuum line into chamber of carb and flooding it.

Taken it up and down the road a few times already, running like a champ bit still a lot of work to be done like changing the 5 year old oil o.o

[JohnnyBravo]

Originally Posted by Lap202

Haha you are so so wrong and I am so so right :P

@RacinNinja

[RacinNinja]

Originally Posted by JohnnyBravo

@RacinNinja

Cant be right all the time. Wasn't sure what he meany by this and failed.

Originally Posted by Lap202

The problem started after I removed the vacuum petcock.. vacuum.. to work it needs a vacuum line. I realized I ran fuel into the vacuum line when I removed the petcock.

.

[JohnnyBravo]

At least we all learned the vacuum peacock needs its vacuum

[Lap202]

Haha I will probably never be right about something again so had to troll a little :P still can't believe after 2 carb teardowns it was that simple

[JohnnyBravo]

Been there done that... Start simple an work up

[Lap202]

Till its time to put it away, I'm going to stick to simple stuff like replacing mirrors and changing fluids on the bike as only God knows the last time they were checked.

Once winter hits, I'm tearing every thing apart and doing a bunch of body work. Also planning on doing a pw50 lower bore'd to 60cc. Get myself up to the city speed limit :P 30 is just too slow lol

This is definitely a great learning tool.

[Alex]

Glad it's working!

[Lap202]

Originally Posted by Alex

Glad it's working!

Me too!
Carb had a screw fall out and is pouring gas out so need to take carb put and replace screw. Today I added a horn to make it street legal, 2 new mirrors, and finally got a battery for it.

Need to come up with a custom mount for the battery tho as the old 6v was tiny so upping everything to 12v also includes a battery that's twice the size.