rebuilding a lil Yamaha 50cc dirtbike (help?)

[lbrowne]

A buddy of mine gave me this bike because the motor is seized and his son has long since outgrown it.

Needless to say, my son at 8 years old is a little big for it, but it's something he can handle as far as size and weight goes for his first bike since he's a skinny little runt like I was.

This is the first motorbike to enter this household! I know nothing about bikes! lol

I'm pretty good with a wrench, but everything I work on has 4 wheels. We already got all the plastic off, muffler removed and clutch cover.

There were some lock washers that got thrown around from something on the clutch side, scour marks on the backside of the cover. Seem to be the right size for the shaft that sticks out the middle.

Looking for help to rebuild this with my son. He is beside himself excited about this. I've had him help with work on cars all the time but this is the first project focuses around him.

I think the cool thing about it is, we're both learning this new for the first time.

Any recommendations or anything would be greatly appreciated!

Here's a pic, she needed a good cleaning from sitting in a garage for years untouched.

I'm thinking a rebuild kit to start but not sure how much I need, or how to check on what I need...


Cheers

[lbrowne]

We got the cylinder head etc off and took a look at everything. Got some pics for you fellas. This piston looks pretty worn, the cylinder head is really blackened with carbon.

I also got a pic with the trans cover off so you can see the washers that were just in there and you can see the scrape marks on the inside of the cover. How can I tell if the trans is still good? Those lock washers seem to be a perfect fit on the center shaft of the trans.

We can turn it by hand the piston moves with connecting rod no problem. Cheers.

[lbrowne]

So in talking to the previous owner, he said the bike slowly got worse where it would sometimes catch when you started it and said it was "slipping" sometimes when it did.

Then his son was riding it when she locked up and died.

It actually might be the transmission then. Not sure how much there is to that. Better get a factory service manual I guess lol.

[Eric]

Thats awesome. I've got 2 PW50s. One for my 4 year old son, and one for my 3 year old grand daughter. Awesome starter bikes.

These things are the same through the years. Go to www.yamahaownershandbook.com.au
Put in motorcycle, skip model and put in 2004 as the year. That will get you the factory service manual.

Good luck and have fun.

[lbrowne]

I've gone to that link and tried to do what you said but I can't locate the manual. Cheers

[Eric]

From the main page at yamaha-motor.com/au type manuals in the search box and hit enter.
Click the link - I wish to obtain an owners/operators manual for my unit.
From there click Owners Handbook
That will get you to the handbook page. Select motorcycle, skip the model and put 2004 for the year.
Pick PW50(S) from the list and you'll get a PDF copy.

You can get a top end kit with new piston, cylinder and head fairly cheap.
Thats actually the generator with the lock washers. looks like the nuts missing.

You can do a google search and find a PDF copy of the parts catalog too. That will help you identify parts and put it all back together.

Good luck

[lbrowne]

How do you install this kick starter spring? I see the stud that the one end loops on, where does the other end go?

http://www.bikebandi...146334sch136131

I can't see the other end...

[lbrowne]

lol nevermind I got it.