Well, the YZ80 is as good as done!

Last night I put the stickers on which went suprisingly well.  I used a product called Rapid Tac application fluid.  It really helped a lot - you can have a few goes at getting the decal aligned correctly before it sticks permanently.

The rear brake caliper is also done - no probs there.  Just waiting on the new front master cylinder from the states to make it complete.

I'll let some pictures do the talking!

Massive thankyou to my beautiful fiance who allows me, a grown man (supposedly) to completely turn one room of our house into a second garage to build a childrens motorcycle!

Also big thanks to my Dad who's machining skills went into rebuilding the kickstarter and also machining the original rear disc.

Can't forget Doug, our black pug dog who 'helped' at every stage of the rebuild!

Getting close now!!

First time it's been back on it's wheels since my first post when it looked like this:

To do:

Rear caliper
Front brake master cylinder (found a new old stock one in the states - on it's way)
Decals

:)

Just a quick update today.  Front end is all done and I've moved onto the rear wheel.  When I pulled down the original wheel I found that the rim was heavily buckled:

No saving that, so I bought an aftermarket rim that is 99% the same.  After rebuilding the hub, I laced it into the new rim.

Here's a vid I took of that process - a good excuse to test out the time lapse app on my new phone!

Should have it back on it's wheels in the coming days.  Then its just a matter of the rear caliper, front master cylinder and the decals.  Then, I can finally get stuck into my Mini race car project again!

Rebuilt the front caliper today.  Nothing special, just the usual disassemble, clean, paint, reassemble with new bits.

I tried rigging up the old rear master cylinder to push the pistons out but I think the seals are gone - didn't build up any pressure.

So, I cut the old brake line and hooked it up to the compressor.

100psi later and they popped out!

The rest was easy, a bit of paint, some zinc plating and some new parts and some reassembly.

QA approved by Doug:

Again, I've left it too long between updates.  However, I've made some real progress on the YZ80.

The next part of the restoration was the front suspension.  This was something that I wasn't looking forward to for some reason but in the end it turned out really well and was quite enjoyable to do.

The forks were leaky, the front wheel had been painted in thick, black paint and the spokes were mismatched and rusty.  That's probably why I wasn't looking forward to getting stuck into it!

The last time (a looong time ago) I've been involved in stripping down a set of motorbike forks I ended up getting stitches in my head (thanks Dad!) - maybe another reason I was apprehensive!  This time it all went well, no trips to emergency.

The forks had no oil in them, just some old gunk.  Plenty of cleaning of all the parts  and then re-assembly with a rebuild kit and they came up really well.

The triple clamps were cleaned, blasted and painted in the closest silver I could find to the original finish.  All I have is a before shot of them:

The handlebars were next.  Unfortunately they had a bend in the crossbar so some heat and some persuasion and they straightened up like new.

And then the part I dreaded most.  The front wheel.  No better way to do it than just get stuck in.  First, the easy bit.  Strip it down - with bolt cutters of course!

I then stripped the flogged out bearings out of the hub and blasted and painted that.  With new bearings pressed in and new seals, it came up like new.

The rim required heaps more elbow grease.  The black paint was very thick and hard to get off.  My little sand blaster struggled with it so I had no choice but to paint strip it.  I hate paint stripper!

Underneath the rim was in decent condition but still had some light scratches and corrosion so I need to fix that up.  The original finish would have been silver anodised I think.  Rather than have that done and potentially not be right, I thought Id have a go at painting it.  Glad I did because it came up great - the finish looks just like the original.

The paint is actually a chrome plate look-alike.  It costs about $20 per can but it's good quality and well worth it.

I managed to find some NOS (New Old Stock) spokes.  So, next job was to re-lace the wheel and hub.  This turned out to be much easier than expected and was good fun.  On these rims the spokes are all the same length and bend.  So, they can only really go in one way.  If you are methodical and patient about it, they all go in easily.  Best tip is to have a photo of the rim with he old spokes handy.

I then trued it up on the bench, tensioned the spokes and temporarily installed it on the bike.  I've managed to find the original style Dunlop tyre for the front which hasn't been made for a while (you can see it in the pics below).  I'm still looking for a rear.

I had a NOS brake disc so I put that on the hub with new bolts.

So, it's getting really close to complete now.  Brakes, rear wheel, tyres and then the decals.

Wow!  It's been a long time since the last update.  Things have progressed slowly on the YZ80 project due to me being distracted with the Mini.  I've been busy planning and collecting parts for it - to be detailed here soon.

Untill then though, I really have to finish the YZ!  The last thing I want to do is have it sitting here 75% done for the next few years (I'm really good at that!).

Ok - an update on the YZ:

So, one thing that I've been looking for is a new airbox.  The one on the bike was a bit tired and had one of the cast-in nuts that fastens the box to the frame was chewed out and missing.  Problem is, the airbox was unique to the 1993 and 1994 YZ80's.  In 1995 they changed slightly for some reason.  As a result, the original box is hard to find. So, I fixed this one.

First problem was the chewed out mounting nut:

It looks as though someone has got a bit excited with the spanner and twisted it out.  So, I went to the hardware shop in search of some sort of castable epoxy resin.  I found this stuff instead:

It's an two part epoxy putty.  I'd never used it before but figured it would be worth a go.  It worked perfectly!

Once set, this stuff is very hard and feels as strong as the other cast - in nuts.  A bit of sanding and that job was done.

The rest of the work on the airbox was just some elbow grease - cleaning, blasting and sanding in an attempt to smooth out the years of battle scars.  After that, I primed it and painted it in a black paint that looks almost identical to black plastic.  All in all it came up ok considering how it looked to begin with. 

Installed on the bike it looks even better.

With that done, I was able to fit up the plastics properly for the first time.  It's looking more complete now!

Next - front end.

A few more things completed on the YZ project.  The first was the fuel tap.  A pretty simple job really.  First job was to strip it down.  Doesn't look very happy to be apart!

Once it was stripped down I compared the parts found to those on the Yamaha parts diagram.  It must have been leaking at some stage because someone has added two extra seals that shouldn't be there.

The main body and lever are aluminium and have the same finish as the carby body.  The front plate thingy is steel and looks like it was zinc plated. 

As with the carb, the main body and lever were lightly sand blasted and then soaked in kero to get the desired finish.  The front plate was cleaned and sanded with 2000 grit paper before zinc plating.

From there it was just a matter of reassembling with new seals and screws and then installed on the fuel tank.  Job done.

One part that has been bugging me for a while was the chain slider / guide that protects the swingarm.  The one that was on the bike was well worn so I sourced a new old stock one.  Problem is, instead of being a nice black plastic, it was an ugly army green!

Looking through my collection of photos of 1993 YZ80's showed that when they were brand new, like in the magazine tests etc, the chain guide was black.  All of the second hand bikes show them in different shades of green.  Strange.  I can only assume that they loose (or gain!?) colour over time with UV exposure.  Even though my new old stock replacement was still in the original packaging, it had turned 90% green.

Anyway, I wanted it to look new - black.  I could have painted it but thought that was a bit dodgy.  So, I thought I'd have a go at dying it.

I used some Rit fabric dye that I found on eBay.  It comes in a little packet in powder form.

First step was to get a pot big enough to fit the part in, fill it with water and get it hot on the stove.  I had it just below boiling and then added the dye powder.  I wasn't sure how much to add so I just put the whole packet in and mixed it up.

Once it was mixed I backed off the temp so it was hot, but not bubbling at all.

Next, I used a zip tie to suspend the part in the dye so it wouldnt be resting on the bottom.  I figured that if it was resting on the bottom it could potentially melt and it wouldn't get an even coverage of dye.

With the part hanging on a piece of timber and in the pot, I left it to cook for about an hour.

After about an hour, I took the part out, gave it a rinse in cold water and dried it off.  Luckily, it worked!  It looks like brand new black plastic again!