82 kdx80 relife build

[kyillest]

well i'll start with saying hello,

i didnt really want to join the forum more of a lurker but i figured be a good way to ask a few questions. names kyle i'll start with the origin of journey over 2 years ago sept. 12th 2010, woke up , missed ridding, sold my rm80 few years back and few of my friends were getting back together and going religiously ridding .

jumped on craigslist and found a ad for a 89 kx80. very poor picture in the ad from about 20ft. called the man up . drove to his house. noticed right away, hey no radiator.... so its aircooled? asked the guy what year is this? he swears its a 89... he kicked it over and it ran. what ever, i handed him 300$ and brought it home. gave it a wash . and a nice clean assembled all the plastics and went out with some buddies .
pics of day 1




i'll note that i was 20 year old 6ft at the time. i always liked the smaller bikes because thats all i ever rode. bike was doing great friends laughed how we bought a 300$ barnfind and were ridding the same day. about 3 hours of ridding in and bike didnt have enough steam, got stuck in a sandpit and just let the bike fall over.

bike fell over and shut off. and thats the last time she ever ran.

i pushed it home. took off the plug and found a replacement. installed it . nothing. took a quick peek at the carb , getting fuel. found after removing plastics that it didnt have a air filter. slightly worried me. wondering if sand got into places it shouldnt.

so removed the carb and the head cover and right away can see marks at the top of the cylinder. worried took off the cylinder head. had 2 small scores but intact. piston was ok, sanded down the cylinder walls with some proper sand paper . re aligned the piston rings and put the cylinder head and carb on. of course still nothing didnt really fix anything.

ran the vin comes up 82 . ha! later discover this a a kdx 80 not the bit disappointed though. atleast i knew what i actually had now. but found out quick parts werent easy to source for such a old vintage bike.

had a pal check peek at my carb . noticed right away had to needle and seat. nothing was in the bowl either? did i really just ride a bike with no needle and seat in the carb? didnt know it was possible. well researched some part numbers found i had a mikuni 28mm carb iirc . went on bikebandit.com because my local parts guy couldnt locate any parts for that carb and found a needle and seat for the carb. also picked up a universal airfilter foam from uni

put the needle and seat in and the airfilter cut to size and put in the air filter cage . and try to kick her over... nothing shocking.

bike sat in the corner of the shop for about a year . i'll update more tomorrow !

[Julien D]

Glad you decided to join! Great barn find. Parts for that will indeed be difficult to source. There aren't a lot of old aircooled KDX 80's still kicking around.

[kyillest]

thanks. yes there is a struggle finding parts. even brochures or anything. i wanted to find specs and what not. very limited market on this bike.

sitting like this


ok so after a year of sitting. i decided that it cant sit any longer. alot of the plastics were broken such as front fender, side panels and rear fender. it wasnt a looker nor did it start so i decided just to start giving it a thorough cleaning one day and get the motivational blood pumping again. i searched high and low every where for a oem front fender. at the time with no luck, also looking for the correct circular front number plate other then the aftermarket square one that the bike came with but again no luck.

i gave a small repair to the rear fender to salvage it (the damage is hidden)
unfortunately i had to settle for a aftermarket front fender at the time because there was nothing available
i did manage to find a side panel that i needed on ebay for a good price! i was happy about that .
also saw some of these kdx80 vinyls and managed to find a unitrac vinyls for the swing arm.

(can see the old broken plastics on the floor)

before i mounted the front fender.


took a few hours of cleaning to get it back to this stage. but hey it was starting to look like a bike

once that was done i got the volt meter and was trying to figure out what was up.
discovered nothing coming out of the coil. that lead me to fix a signal wire, and a ground but still nothing. back tracking a little further now i removed the flywheel to see what is up.

and found the magnet had broke? did it crack and break when the bike fell? did it break from removing it without the proper tools?

looking around further i discovered new keyway on the crank? now i'm like how in the world did this bike run?

the condensor and coil windings didnt seem too damaged


so this brings me to today. im guessing by a cracked flywheel/magnet and no key way the timing would be way off. so im starting there to order a few parts . anything else should i replace while i'm there. like it doesnt really solve my lack of voltage problem. condensor,points? windings?

i may just replace the whole assembly . as there is a few known good parts on ebay at the moment

[Julien D]

Yeah, the busted flywheel magnet could be the root of your problem. These older KDX's are notorious for that sort of damage. You could probably epoxy that piece of magnet back and install a new woodruff key to see if it'll run.

I have to say, at 6' tall, I imagine that bike is nowhere near enough to haul you around. Have you considered something with a little more juice? I hear ya on liking the small bikes. I still pull my first bike out once in a while and ride around the yard. It's a 1981 XR80 that I have had since it was new.

[kyillest]

haha no the bike is small. i do want a bigger bike. but i couldnt let this ol girl just go to waste. if i sold it the next owner would probably never finish it and junk it. so i plan to make a good running bike and perhaps trade out of it or sell it later.

edit* does any one know where i could find the correct woodruff key?

[Julien D]

I'm fairly certain you could find something to work at your local hardware store. I am not sure whether the same key from another model would work. Perhaps you could make a little clay mold of it to take with you for size comparison. It just needs to fit inside the slot, and protrude a little bit.

[KDXGarage]

Are you sure the stator is stock?

[kyillest]

Are you sure the stator is stock?

good question . the connections on the condensor seemed to be soldered in form the coil windings so im guessing its a oem unit. never really crossed my mind. why do you ask?

[KDXGarage]

It is a grainy picture, but I am wondering about the quality of the wiring...makes me think it is not stock or at least altered.

[kyillest]

altered perhaps.

i just bought a flywheel, woodruff and new stator assembly off ebay. for a good price so i'll just change it all. any pointers when putting the this all together? loctite the woodruff? or something like that? torque spec for the crank shaft nut?

[KDXGarage]

Get back on ebay and get a manual. Look on y website to check the VIN, then look for the proper part number for the owner/service manual.

[kyillest]

slapped the new parts in. no dice.

manual has been ordered, thanks for the website jay

now i'm waiting.