Posts
40
Joined
2/22/2009
Location
New Baltimore, MI
US
Edited Date/Time
9/30/2022 2:20pm
Guess she was a Ice Racer out on Lake St Clair in the winter months.
The tear down when fairly quick.
She was sitting inside a old leanto next to a barn.. the lean-to roof collapsed, and she sat exposed to the elements for a few years.
Found a old Pro Circuit Pipe under that paint and welded on heat shield.
The air box was shredded from the ice tire.. I thought this would be a difficult find, but it was the easiest of the build.
Frame is ready for blasting, welding and powder
The motor was rusted stuck (CHECK THAT FLYWHEEL WEIGHT)
The cylinder had two spark plug holes, this would work out to my advantage...
The crank was pretty stuck and took some work to break loose.
The crank eventually came out with a little work and brass hammer.. the cases needed some attention also.
new bearings needed throughout the engine
The crank was blasted, rebuild with O.E. parts and balanced.
Once the cases had all the bearings removed, we had them blasted a ceramic coated a nice matte black.
Time to start re assembling - Ended up needed a first gear and two shift forks. The shift forks were easy to find (found some NOS ones on ebay), but the first gear took a little longer.. I bought a couple used ones on ebay that looked good, but they were junk.. ended up finding a NOS gear overseas.
Remember that 2nd spark plug hole? Im going to use it for the push button decompression release
New bearings, new bore, new piston, crank, shift forks and a gear.. also reassembled the motor with 8mm bolts and threw the OE allen head ones to the curb.. rebuild a motor with new nuts and bolts is a great way to make it look new again.
The tear down when fairly quick.
She was sitting inside a old leanto next to a barn.. the lean-to roof collapsed, and she sat exposed to the elements for a few years.
Found a old Pro Circuit Pipe under that paint and welded on heat shield.
The air box was shredded from the ice tire.. I thought this would be a difficult find, but it was the easiest of the build.
Frame is ready for blasting, welding and powder
The motor was rusted stuck (CHECK THAT FLYWHEEL WEIGHT)
The cylinder had two spark plug holes, this would work out to my advantage...
The crank was pretty stuck and took some work to break loose.
The crank eventually came out with a little work and brass hammer.. the cases needed some attention also.
new bearings needed throughout the engine
The crank was blasted, rebuild with O.E. parts and balanced.
Once the cases had all the bearings removed, we had them blasted a ceramic coated a nice matte black.
Time to start re assembling - Ended up needed a first gear and two shift forks. The shift forks were easy to find (found some NOS ones on ebay), but the first gear took a little longer.. I bought a couple used ones on ebay that looked good, but they were junk.. ended up finding a NOS gear overseas.
Remember that 2nd spark plug hole? Im going to use it for the push button decompression release
New bearings, new bore, new piston, crank, shift forks and a gear.. also reassembled the motor with 8mm bolts and threw the OE allen head ones to the curb.. rebuild a motor with new nuts and bolts is a great way to make it look new again.
next was cleaning all the small parts. I quick bath in Apple Vinegar and wire wheel had them looking good again. I would rather vapor blasted them, but I didnt have access to a machine at this time.
Cleaned and ready..
Ebay Day!!!!
The air box I was worried about finding was delivered in a few days and in better shape than advertised.
Fresh seals between the boots/box and new nuts and bolts ( Bolt Hardware / Magnum Distributing )
UPS dropped off new fork and shock springs for my weight along with race tech Gold Valve Cartridge Fork Emulator kits and a shock kit.
fresh out the oven and ready for re assembly
one thing people forget is to clean the threads after coating. I seen many people snap off little 8mm bolts
SCORE - Found a 1984 NOS YZ490 Answer Silencer
New hardware is a must !!
IMS Footpegs replaced the tiny stockers.
All Balls pretty much has every bearing and seal kit for these old MX Bikes. New Wheel bearings, stem bearings, swingarm bearings and linkage bearings.
Another SCORE - Old Yamaha YZ490/WR500 Top clamp.
It fits (with new hardware of course)
New rims and spoke arrived and ready to lace.
Shocks rebuilt and installed with new bushing (shock bearings)
NOS yamaha throttle assembly witch I didnt use... I replaced the Mikuni Carb with a 38mm (or 39mm??) Air Striker. When I did this I changed to a Honda twist throttle assembly. This also allows me to run the new style lock on grips
Looking like a bike (sort of)
New DC plastic except tank. * People seem to give DC greif for not looking like "stock" - fact is nothing looks like stock, except stock and most this stuff was discontinued before the first gulf war :/ But the DC stuff looks really nice and first perfect! I never needed to drill out one hole!
My dog seems to approve, or he was thinking about pee'ing on it.
Titanium bolts for the engine mounts and triple clamp, just because...
Engine slide back into the frame with little effort.. so much easier working on air cooled 2-strokes than the new CRF450R's
The Old Rusted Pro Circuit pipe was blasted, welded, small dents filled, and ceramic coated a Yamaha Matte black and fit perfectly to the Answer Silencer.
Its starting to look like a bike again
All these little specialty bolts and spacer disappeared from the bike over the past 40 years.. Luckily Yamaha still offers most of them.
I wanted the OE look, so I just went with a quality Regina "natural" chain.
The Shop
Free shipping: VITALMX
Luxon 4-Post Bar Mounts
$189.95 - $239.95
Just need to head over the machine shop and install the De-Comp and its ready
Can you give more info on your wheel build? What did you use for rims and spokes?
Pit Row
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