Another pitbike project!

[swiftb]

So this is very much along the lines of Ojaxos thread in here. As its pretty much an identical bike!
Picked it up today cost me 65 notes. Also came with a complete spare rolling chassis, spare engine (in bits) spare carb, spare set of plastics, tank etc etc. (so basically 2 bikes - one good - ish and one pretty much fuked )
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2548.jpg
Its a py90 - 90cc semi-auto 3 speed. Has Jupiter written on casings?? Copy of a Yamaha pw80 with a Honda copy engine.
Anyways seems ok - I knew it had running problem so got to get to work on fixing that basically.
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2550.jpg

At first glance tonight its going to need the following doing:

Running problem to be fixed - fires up and runs on choke but when choke shut off it cuts out. Also when under full throttle it borks and then picks up again in a sort of rythmic fashion - bit bizzare.

Front brake doesnt work - cable has broke off at hub so probably just a swap from the donor bike.

Rear wheel has spindles missing and appears buckled - again should be a case of a swap from the donor which seems ok.

Stand broke of frame - can stay like that

Footpegs, there shit - better ones needed.

Plastics - not too shabby, clean up and maybe a cool sticker kit.

Chain - its rotten - good one on the donor tho

Small rip in seat - some kind of repair required

Left hand grip has seen better days

Various things are loose like the swingarm and rear shock - looks like they have been swapped from the donor but not tightened.

When the bike is shut off/cuts out - fuel proceeds to piss out of the overflow pipe on the carb.

Also needs a good clean!

So all in all theres gonna be plenty to keep me busy over the winter which was the idea. Both frames have vin numbers - may even collect some bits and make a good one out of the spares yet but concentrate on getting one looking sweet first!

Will update as and when

cheers

[oJaXo]

looks like you got a lot better deal than i did on that one mate
looking alot nicer and cleaner than mine
be looking forward to seeing your progress and possibly nicking a few of your ideas

cheers
____________________
A2 License - 26/03/09 PASSED!
Fs1e -> 03 dt125r -> 99 Hornet 250 -> 95 CB400 Super Four R - > Hornet 600 2013

[swiftb]

Just a small update. Been investigating the running issue for a few hours today. Not much further forward with regards the full throttle issue but some improvements after adjusting the valve clearance and air/fuel mixture.

Further investigation tommorow if get chance.

Some more pics for now ;

whats left of the donor
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2560.jpg

after a quick clean
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2562.jpg

Back end sits reallllly low so rather than replace the shock like Ojaxo has, and since I have two good shocks anyway I plan to make a small extension piece to push the swingarm away from the frame about another 30mm which should raise it up a decent amount. (also i am a tight bastard so the less spent the better )

[oJaXo]

looks good
just thought id let you know when you do put the rear end up just keep an eye on where the chain runs out from the front sprocket, mine was catching quite abit against the bottom of the engine casing

cheers
____________________
A2 License - 26/03/09 PASSED!
Fs1e -> 03 dt125r -> 99 Hornet 250 -> 95 CB400 Super Four R - > Hornet 600 2013

[swiftb]

[swiftb]

Update - After some time spent on the bike I managed to fix the Bogging down issue. After changing various pits and pieces and much fookin about I decided to check the valve timing. Hey presto it was a tooth out! Timed up on the F mark at the crank rather than the T mark. So the bike runs pretty much sweet as a nut - apart from the previously mentioned oil burning.

Had an hour or spare tonight so got to work:
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/workbench.jpg
Weight bench makes an awesome pit bike work station

Head and barrel off
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2572.jpg

https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2569.jpg

Barrel and piston are in great condition tbh, but looks like a bit of blow by above the gudgeon pin area - so hoping this is where the problem lies.
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2579.jpg
Barrel is like new so im going with a piston and ring kit and see how that turns out. Parts ordered tonight need so source a gasket kit now.
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2581.jpg

Hmmmmmm, further inspection seems to look like could be headgasket/oil way o-ring which was letting oil into the barrell. The lot will be changed anyway as never can be 100% with these things
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2584.jpg

Pictures are bit out of focus thanks to my shat camera

[swiftb]

Progress is at a halt at the minute - still waiting for a batch of parts to turn up

Today I decided to investigate the spare engine - it was mostly there in various bits. Was actually seized up solid so stripped head and barrel to see why. It looked like its hydrauliced. Had water in the barrel and the top of the barrel had a nice rusty layer round it, piston seized in solid. Got it all apart and give eveything a good clean and lube up.
Reassembled it and she spins over! So I decided to see if it ran. Rebuilt with all old gaskets for now, good compression so borrowed various items from the good engine- carb, cdi, kickstart etc.
Quick oil change and kicked it over. She fires up and runs! Goes through all the gears sweet as well.
So now have a good spare engine (will need new gasket set fitting at some point)

[img]https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2591.jpg
Spare engine mocked up in the spare frame


Im now trying to decide what to do - i reckon to build the spare bike to a half decent standard with the spare engine in its going to cost around £160. But at that its going to a basic , average condition py90.
Not sure if its worth it really. May fit it into a modern pitbike frame but not sure how much a rolling chassis for something modern would be or how easy it would be to get hold of

[oJaXo]

had any luck with the burning oil issue with the other engine mate?
____________________
A2 License - 26/03/09 PASSED!
Fs1e -> 03 dt125r -> 99 Hornet 250 -> 95 CB400 Super Four R - > Hornet 600 2013

[swiftb]

[oJaXo]

ideal:up:

tempted to do something with the plastics
was thinking about ether modding a different set of plastics to fit or cutting and changing the originals on there to look abit more modern-ish

what you think?

cheers
____________________
A2 License - 26/03/09 PASSED!
Fs1e -> 03 dt125r -> 99 Hornet 250 -> 95 CB400 Super Four R - > Hornet 600 2013

[swiftb]

[oJaXo]

fair enough

that looks like awesome fun mate.
wish there was a track like that down near me
____________________
A2 License - 26/03/09 PASSED!
Fs1e -> 03 dt125r -> 99 Hornet 250 -> 95 CB400 Super Four R - > Hornet 600 2013

[swiftb]

Received the new piston kit and gasket set so engine is now rebuilt. Any other work is pretty much cosmetic now so time to give it a good run out at the nearby enduro track - once the weather clears up a bit

barrel cleaned up
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2598.jpg

head cleaned up
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2601.jpg

new gasket and seals and piston kit fitted
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2602.jpg

Rebuilt
https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2603.jpg

Had a little blat round the garden today and engine seems to run sweet enough now - still seems to be burning a bit of oil though. Nothing on the scale of what it was before the rebuild but bit pissed off that it still smokes a bit.
Maybe the stem seals are leaking a bit but to be honest it can stay like that as its only slight and not really a major issue. Could even be the oil is a little too thin.

One thing that has seriously pissed me off however is after re spoking the rear wheel and swapping the tyre over (which was probably on par with wrestling an alligator ) I was waiting for a tube to turn up. Well the tube came and after another fight with the rear tyre/wheel I managed to get the tube in and tyre on - sorted. So I thought, seems ive punctured the tube getting the tyre on so its gonna have to come back off again. Swine

Next plans - drill frame to mount the shock approx 30mm further back to raise ride height

Clean up plastics and fit sticker kit

Tidy up cosmetically (bit of paint here and there) and retrim/replace the seat

Ride the son of a bitch

[oJaXo]

looking good

eyed up a sticker kit for it yet?
____________________
A2 License - 26/03/09 PASSED!
Fs1e -> 03 dt125r -> 99 Hornet 250 -> 95 CB400 Super Four R - > Hornet 600 2013

[swiftb]

Yeh got some stickers just need to get the plastics prepped before I fit them. Ive had enough at the min tho, too sodding cold! Think I got mild frostbite today
Got to try and keep the costs down now as its starting to mount up. Theres all sorts I could buy and im tempted to go wild on it but I keep reminding myself its a py90 at the end of the day!

[Gazdaman]

Changing the inner tube without removing the tyre is nicely easy.

It's WELL worth getting someone to show you how to do it for the first time. Someone experienced showed me how to do it first time and it made it lots easier from then on.

Looks like you've done a decent job. And the smoking oil could be cack in the exhaust. And you might find it stops once you've ridden it for a while.

Gaz

[swiftb]

Cheers Gaz,

ye I wont be fully removing the tyre to change the tube, but the carcus on these little 12" blighters it tight as hell, need to pop one half of the tyre off the rim to get the tube out.
Ordered a spare tube incase this one wont repair anyways.

Got a sticker kit sorted here is the progress with it so far. Still got number board to do and front fender but this is how its looking.

https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/rockstar.jpg


Not far off now, just need to get the ride height and puncture sorted then the cosmetic stuff can wait until it warms up a bit as spraying paint on too freezing cold metal isnt going to give a great finish

ps. I do realise a mixture of red bull and rockstar may not taste too clever

[swiftb]

Another shot from the rear

https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2615.jpg

Note the stunning tailpipe addition

Ok so got the numberboard sorted and I raised the ride height. Looks a lot better for it I think.

https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2616.jpg


Havent taken any photos of adjusting the height as its not particularly interesting. But basically I drilled the frame where the shock mounts approx an inch further back to force the swingarm further away from the frame, effectively raising the height.

I like this shot - looks like its raining fireballs Unfortunately its not, its snow - more of the bastard stuff

https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2620.jpg

https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2617.jpg

https://i441.photobucket.com/albums/qq135/photobucca/mini%20bikes/CIMG2618.jpg

Dont want to spend much more now so this is pretty much as far as it will go apart from tidying up whats already there, few stickers for the front guard etc - although im tempted with the odd addition like some decent pegs etc

[oJaXo]

looking good

have you raised to the max height now then?
____________________
A2 License - 26/03/09 PASSED!
Fs1e -> 03 dt125r -> 99 Hornet 250 -> 95 CB400 Super Four R - > Hornet 600 2013

[swiftb]

Not quite max height, theres still a few mm play, just didnt want the swingarm fully topped out (not that it really matters once you sit on it i suppose)
See what you mean about the chain rubbing on the lower casing. Maybe a little chain runner bonded to the inside of the casing, what you reckon?

[oJaXo]

yeah thats what i was thinking with the chain rubber on the bottom of the casing.

ether that or grind a part off the bottom of the casing

dont think it rubs when your sitting on the bike does it?
havent actually had the chance to ride mine for so long i forgot

cheers
____________________
A2 License - 26/03/09 PASSED!
Fs1e -> 03 dt125r -> 99 Hornet 250 -> 95 CB400 Super Four R - > Hornet 600 2013

[baldy]

You need to give me that spare rear shock and carb.

You REALLY need to.

Please.
____________________
One day i will rule the world, just not today.

[swiftb]

[PEEWEE109]

hi bud your py90 looks cool yeah , where did you your stickers from as been trying to find some for my py90 , cheers