KX Riders
Maintenance & Technical => KX250 / KX125 => Topic started by: 2 smoke juan on September 02, 2008, 11:17:07 AM
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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.
(http://i191.photobucket.com/albums/z270/magicjuan77/C15/91KX125circa1994.jpg)
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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......
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Looking good! :-D
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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 :mrgreen:
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.
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That looks great! 8-)
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/
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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 :-D 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
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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. 8-)
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. :oops:
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
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what did you use to polish your engine?
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Very nice restoration, looks better than new.
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what did you use to polish your engine?
Nothing more than Autosol metal polish applied by hand
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Very nice restoration, looks better than new.
Cheers man, taking longer than i'd like but pleased with how it's coming along!
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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.
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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?
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very very nice resto
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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?
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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?
Ok cheers dude, thanks for the info I will get some N.O.S plastics myself.
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Got a bit more done to the bike today :-D
Replaced the reeds in the rad valve and installed it along with a new boot and clamps.
Also installed the carb along with new breather hoses, N.O.S throttle assembly and cable. Ditched the stock grip for my preferred renthal medium compound grips - took forever to cut the stocker of the new throttle tube!
Got round to tidying up the wiring, weatherproofing it for some fun in the Scottish mud!
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The rear brake assembly also got some attention today.
Piston was seized in the caliper with the bike having sat for so long - for a right pain in the hiney to get out, but a little persuasion with the airline and it was out. In my haste i didn't really take to many photographs of the calliper and master cylinder rebuild - will take more when doing the fronts - with a how to if anyone is interested.
Anyway the calliper was thoroughly cleaned and got a new fluid and dust seals, new piston, new bleed niple, all new rubbers for the carrier sliders, new pad holder pins, anti rattler clip spring and new Vesrah sintered pads.
The master cylinder was stripped and i found the push rod to be severly corroded and was beyond saving. New parts included a new return spring, push rod, seals etc along with a new reservoir :mrgreen: This lot was all connected up with a Goodridge braided carboline hose with stainless fittings - looks the part........
NOS parts for the back brake rebuild alone cost a fortune - nearly ?250!!!
Hopefully get started on the front tomorrow night after work!
Anyway here's the pics
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Lat pics for this evening
New Pro Circuit expansion chamber installed! 8-)
and how it stands as of tonight - not much to do now, CANNOT wait to get it out and run in the motor then get it on the dyno and set up for the winter races here in Scotland.
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verry nice build up!!!
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You work is stellar :-o Its hard to tell which parts are new and which ones have been restored. Also 2 thumbs up for taking it racing when your done!
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wow, really nice job.....
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That looks awesome, I love restored bikes, especially with NOS parts.
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WOW! Amazing job! :wink:
Where did you buy the pro-circuit pipe?
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WOW! Amazing job! :wink:
Where did you buy the pro-circuit pipe?
Cheers bud.
I bought the pipe from CGH Imports, they're the PC importer to the UK.
Wanted a works pipe rather than the platinum finish but not one of PC's dealers or importers worldwide had stock and PC wouldn't make me one haha
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Update on rebuild - didn't have much time to post these. Date back to December :-D
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All finished - well pleased with the results!
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Last pics
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Great work Juan! . 8-)
I don't think I could bring myself to ride it!
Tuck\o/
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Absolutely beautiful restoration you've done there! Nice touches with the tecnosel seat cover and period-correct style numbers. Older bikes with newer font numbers always seemed odd to me. Great job!!
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:-o :-o :-o Man that is very nice. I bet you'll have the best since of pride riding that bike.
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i have a 1990 kx 125 they look olmost the same but yours is way better condition alot actually butit looks like it will fly :-D
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Hey!
Did the 304 silencer make it any louder compared to the stock silencer?
-J
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Very, Very, Very, Very, Very, Very, Very, Very, Very, Very, Very, Very, Very, Very, Nice!!!
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Thanks very much for the kind comments guys.
I really must get out on it but a 6 week old baby girl is taking up all my free time just now 8-)
Jopiz, i can't tell you if the 304 is any louder on this application....this bike hasn't even been started since the rebuild.
It's just sitting as a very expensive ornament in my garage as reminder of my schoolboy career!
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Congrats on a very impressive restoration. Looks amazing and brings back lots of memories of my '91 kx125. Boy was that a fun time.
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better than new good job