Yamaha PW50

[ricky_191]

Hi all. I got a jug to measure fuel in today and used my old idea for the oil and used a 30ml shot pourer/spirit dispenser. I wasn't sure if it would work with oil so I measured it out in a shot glass, just to be sure it was correct.

So i'm running a little bit rich at about 35-1 to 40-1 . I took it out for a ride and it went great. I took my dogs for a run with it and they could just keep up and went about 1.5km in a few goes. It went great and the dogs love chasing me so it saves me walking them

I need to tighten up the handle bars a bit and other then that , it's going so good. I need to put the seat on with a few bolts too.

glad I got the fuel mix worked out now and it's pretty easy to do.

 

[my67xr]

think of it like this,
with premix in your bike running it t 40-1, you have less oil in the mix, so the engine is running drier with less oil to lubricate the bottom end, crank, bearings, piston and rings etc.

so what ratio are you running now ?

 

[ricky_191]

I'm running around 33-1. Does that sound like enough oil ?

 

[my67xr]

yeah, that's good.
it will keep your engine happy for a long time.

 

[ricky_191]

I had a look again and most run 32 - 1 and even up to 40-1. So I think that's pretty spot on. It runs really good and didn't have any problems. I stopped it after 10mins and started it back up after 1min and it went first go and went good.

I don't know if I posted this here before but I had problems with the bike struggling when it got hot or stopping and being hard to start. So after some research I found that the coil can get old and cause problems. So I replaced that and it went so much better. Oil / fuel mix can also do that but I had my mix just about right.

Also while filling it up yesterday. I found a bit of plastic that was in the fuel hole. So after 5-10 frustrating minuets, I got it out. The rest looks clean though.

I want to get new stickers made up for it but I kinda like the old school look to it :/

Thanks for your help

 

[ricky_191]

Hi all. I haven't posted on this thread in a while. My peewee has had a bit of trouble so I put it in the shed and left it alone till I was ready to work on it again. It got taken and then brought back and chucked off a ute -_- After that it never run right and after a while it just stoped going all together. I found out that the stator was broken and a screw had come loose in there and it was all messed up. So I ordered a new inner rotor kit instead of getting a stock set up.

Then I started to clean up the frame and fix up the marks on it and found a big crack. So I need to get that welded back together and might also get a plate welded in there. After that I will re paint it all and put it back together. This is how it looks at the moment

I will also clean up the engine and make that look a bit better and then it should be good. I will post more updates as I do more too it. Thanks for reading.

 

[ricky_191]

Hi guys. I found a problem with the peewee. I took the head off to see how the inside looked and it was all bad in there. The cylinder is scored up on the top and bottom and so is the piston. And it's not tiny little ones also, they are pretty deep.

So I was going to get it bored out but it would cost more then a rebuild kit so i'm thinking I should just get a kit and put that on. Any help or advice would be awesome

My mate also picked up the frame today so that's getting welded up and maybe have a few plates put in it as well. After it's back I will strip it down and repaint it.

Thanks for reading.

 

[my67xr]

yeah, it looks like it's been run with a dirty or no air filter.
and possibly with no oil too ?
Cj's engine had a few scars, but they weren't too bad, a 2nd oversize bore fixed them


just go for the china kit, it will last if you run it in properly.
if you prep the short motor and have it all ready, then you could have it assembled and running in an hour once the parts arrive

otherwise there is a lot of mucking around dropping cylinders off, ordering parts and waiting for parts if you get it all individually

if you get your head milled 1mm, off the gasket face, it takes the compression up from 5.5-1, up to almost 10-1
worthwhile for the extra pull...

 

[ricky_191]

Hey, thanks heaps for your help mate. I was going to get it milled but i'm scared that it's going to wreck it lol. Should be 2 weeks till the parts get here so I have time to work things out.

The frame is getting done today so i'm pretty keen to see how that turns out

 

[my67xr]

where was the crack?
i saw it has been welded around the main tube a few inches back from the headstem tube

i milled the head on Cj's, just used a big flat hardwood block with sandpaper wrapped around it.
started with 80 grit, then 180, then 320
i worked it in a circular motion and checked it was still cutting square every now and then

finished it with some 600 w&d on a thick piece of glass

 

[ricky_191]

It's cracked there and right under all the way though. Just a tad bit dangerous. It would have been a massive yet impressive stack it it snaped while riding it lol He might put some more bracing on it too.

With milling the head.. I have heard of people diying it before aha So it worked out all good ? How do you know how much you're taking off though. I was thinking maybe a pen line and then sand the line off or something.

 

[my67xr]

have a look at the head, on the gasket side you can see the raised lettering from when it was made.
that looks like it is sitting in further than the gasket face, try measuring it, and if it is about 1mm, then sand it back to there.

yeah it is pretty easy to do yourself
there are some pics in my PW50 thread too, of what mine looked like when it was all done
you can feel the difference first time you kick it over, worth the half an our sanding for sure!

 

[ricky_191]

Awesome Could I try and file it down a bit before sanding ? It's about a mm think so i'm thinking I should get it close to the bottom and then sand the rest down.

Also the inner rotor kit come today. It looks pretty well made. It also come with a few stickers lol and that's always a bonus still no news on the frame yet.. It is a free job and i'm in no rush. I'm pretty sure he will fix it up and make it a lot stronger, maybe.

 

[my67xr]

yeah just make sure you keep it flat
if you have a big vise handy, sit it up 1mm higher than the top of the jaws and start filing
that way you can't go too far without filing your vice

 

[ricky_191]

Hi all. Yesterday my little bro helped me pull the piston off and take the studs out so it's all ready for the new stuff to go on. I also got an update on the frame. Only one photo but I think this brace will strengthen that area that snaped. I don't know when I will get it back though.

When the frame comes I will sand it all back end rust treat it and then paint it black. I'm also going to re paint the forks and fit them up as well. I also want to clean up the bar mounts I made so it looks a bit better.

I'm not sure when the top end will be here yet. Maybe this friday Thanks for reading

 

[my67xr]

see the little dag of weld on the left of the l/h weld,
look just above it, i can see another crack in the r/h spar that goes down towards the r/h footpeg mount.

 

[ricky_191]

Yeah I saw that too but couldn't see it good enough on my tiny screen. Now i'm on the big computer I can see it clearly :/ I will have to get the fixed up too then

Good spotting

 

[my67xr]

Cjs' frame had been broken there before too, on both sides, but had been repaired before we got it
as well as where yours' is cracked

 

[ricky_191]

Hi. I'm going to try and get a bunch of plates welded in. I think the extra weight would be worth it. I'm just a bit scared that it will snap while i'm ridding it. I'm going to try and put some better foot pegs on it and also get the rear brake working really good.

I think the front one only needs a cable but i'm not sure. I'm so keen to ride it though and keen to see how much it will improve with the mods.

 

[my67xr]

i used DS80 pegs on Cj's but they needed a small dab of weld on the bottom where they touch the peg mount to sit straight
there are a few aftermarket one available on ebay, from $25 and up
some of your spare pitbike ones might work too ?
pw50 pegs | eBay

china front brake cable $17 delivered, genuine will last longer though
Yamaha PW50 Peewee Front Brake Cable Line Wire Y Zinger PY50 PW PY | eBay