91 KX 125 H2 Rebuild - Bike finished 08.01.09 2nd page

[2 smoke juan]

Hi guys

I finally got my rebuild underway a couple of weeks ago - not rushing it too much as it's getting built to race next season in the support class of the Scottish Twinshock championship.

I've had my little Kwacker since it was brand new, got it as a 14 year old in Sept '91 from Mickey Oates Motorcycles in Glasgow. I had to wait a full year to race it as the S.A.C.U didn't let kids ride 125's until they were 15 back in the day! I raced with the BYMX club and with Irvine motocross club through the 90's, firstly on this then a 95 KX 250 which unfortunately had to be sold later that year to pay rent whilst i was a student in Edinburgh.

I'm about to embark on a full resto of the bike below - it's a 1991 KX 125 H2 - this is how it looked when it was retired back in March 1994.

[2 smoke juan]

So far i've put new steering / head bearings in along with fully rebuilt linkage.

The stock Kayaba rear shock has been substituted with an Ohlins and the fork springs have been replaced with NOS genuine heavier springs along with a full overhaul of the forks.

Upon disassembly i found the piston had a hairline crack, the barrell was slightly scored and the KIPS valves were broken. Among other things the barrel was recoated by Langcourt, a NOS stock piston was put in, every seal and bearing was replaced and a new clutch assembly was installed too. It had a Boyesen rad valve installed from new and i have a brand new Pro Circuit platinum pipe (although i would much prefer a bare works pipe no one has stock and PC won't make me one) and 304 factory sound silencer to put on.

I'm happy with the build so far and really looing forward to racing it against bikes of a similar age next year.

There is a ton of parts all over the garage and the house waiting to get bolted on - only parts i'm needing is a NOS generator cover as mine is pretty scratched but it's purely for cosmetics and a NOS fuel tank - again purely for appearance.

Here's a couple of pics of the Ohlins - came with a nice new top mount piece which was handy as the original was indicating signs of fatigue......

[The Flyin Hawaiian]

Looking good!

[2 smoke juan]

Progress has been really slow due to work comitments but thought i'd show some progress pics.....

Got it rolling now on its new wheels, installed new motomaster discs and renthal sprockets.  Got a NOS RHS radiator of ebay for 40 quid delivered and sent the LHS rad down to GMX in Essex to be straightened out and pressure tested - really pleased with the results. They're installed with new coolant hoses and got the electrics cleaned and installed too.

I'd been looking for a NOS standard size fuel tank but after a light restoration the original one has come up pretty nice, a few scratches still remain but the faded green has been replaced with a nice glossy finish as a result of plenty of elbow grease! 5 hours polishing - yes i really do lead such a boring life! Mounted the shrouds too just to see and pretty pleased with the colour match! Best stock graphics ever on a KX IMO 

Have rebuilt the carb, which is a Keihin 36mm PJ carb rather than the stock 35mm PWK, am waiting for a replacement rubber boot for my Boyesen rad valve and replacement carbon reeds before i reinstall it.

Last pic is of my new PC exhaust system. Hopefully get a bit more done tomorrow so will post more then.

[Friar-Tuck]

                     That looks great! 
 I was trying to find a thread on restoring plastic and keep coming up empty. 
 If you don't mind me asking how did you get that tank looking so good? 
  What did you use to "Polish" with? 
 
 Your doing a fine job, keep it up!
  Tuck \o/

[2 smoke juan]

Cheers for the positive comments Tuck.

I wish i'd taken photographs of the process to show you the condiditon of the tank to begin with.

Although it wasn't too bad, there were a couple of deep scratches and nicks along with tons of minor scuffs. The bike also had a a graphics kit installed previously so there were some tonal diferences in the green where the bare plastic had been exposed to the sun, not that we get much of that here in Scotland right enough!

I had looked at a few different ways of restoring the tank.

If your tank is just faded and not scratched then i'd suggest your first option is to try and heat the plastic gently with a heat gun. This can bring the depth of colour your tank originally had back out. You have to be careful not to over heat the plastic in case you melt it or burn it as this will leave a white mark you'll never get out.

That process wouldn't work too well for me, due to the ammount of scratches in the plastic. So i went ahead and razored the nicks out, then carefully proceeded to sand the tank working through various course, medium and fine papers by hand. I used Plastic Renew from PC Racing in the states to restore the colour. After 4 applications i then buffed the whole tank with wire wool for a further 30 mins then re-applied 2 further coats of Plastic Renew.

I've heard both good and bad reviews of this product, however i reckon those who have bad results generally haven't put the prep time in - definitely a process that thorough preparation and adhering to the instructions pays off. Some have said that the finish doesn't last well on tanks citing that fuel vapours attack the chemical in plastic renew - i'll wait and see what the durability is like but if it fades i'll just treat it again  Overall, although there is one deepish scratch remaining on the left hand side i'm happy with the results as this bike is being built to race.

You could also try polishing with a gel as in the link below - although it doesn't appear to give such a glossy finish....

http://home.hvc.rr.com/projectyz/tips_tricks.html

Or i found this guy who can paint plastic tanks while i was looking at tank resto options - guess he must seal the internal side of the tank with a coating much like you would treat a rusty steel tank so vapours don't pass through the plastic???

http://www.joeabbatescycletherapy.com/images/gasTanks/tibuteWhiteTank1.jpg

Hope this helps

Ewan

[Friar-Tuck]

 Thank you for taking the time reply,
I had a friend that used the plastic re-new and it looked good until he took the bike out, and the finish
 got scratched off by brush etc.      I'm not sure he followed the directions though....
Man your bike looks great. 
I don't think I could bring myself to ride it after all the time and money in the restoration.
    I was afraid to start sanding and totally mess up the tank. 
However now that You gave me some insight I think I'll sand it down and heat gun it.
  Thank you again.
Tuck\o/


Rob
 

[moron]

what did you use to polish your engine?

[Danger4u2]

Very nice restoration, looks better than new.

[2 smoke juan]

what did you use to polish your engine?

Nothing more than Autosol metal polish applied by hand

[2 smoke juan]

Very nice restoration, looks better than new.

Cheers man, taking longer than i'd like but pleased with how it's coming along!

[DAGGITS]

WOW!  I am a 1991 KX 125 owner. I would be afraid to take that bike out of the garage,,,no, I would move it to the Living room and use it a a sculpture. 

[moron]

what did you use to polish your engine?

Nothing more than Autosol metal polish applied by hand

just bought some autosol today, where did you get your graphics from?

[mysnykkx500]

very very nice resto

[2 smoke juan]

just bought some autosol today, where did you get your graphics from?

Got genuine N.O.S plastics, they already have graphics installed. I got one shroud through Bob Tracey's World of Cycles in Pensylvania, the other i had to get from CMSNL in Holland.

If you're stuck i could trace my graphics and send you more detailed photos so you could get some custom made?