Posts
99
Joined
6/12/2014
Location
Norman, OK
US
Edited Date/Time
4/23/2021 10:11pm
My little guy got a Chinese electric bike for his birthday last April and has loved it. He has been bugging me for a gas powered bike, but I’m fresh out of college at pretty strapped for cash so I’ve been putting it off. But I had been keeping my eye out for either a KX 65 or a PW 80. A 65 was my first bike 18 years ago, and the 80 would let him get a decent bike speed wise without having to deal with the clutch. I’ve messaged in over 100 different Facebook ads over the past 8 months, but no luck. Finally last week I found a PW 80 with a blown up motor for $100. I jumped on it and went and picked it up. I’m still not wealthy, but money has been better as of late. I looked up parts for the bike and found I could replace the plastics, graphics, seat, air box, brakes, throttle, bars, carb, head, cylinder, piston, rod, crank, and gaskets for under $400
Basically for a $500 investment I could turn this old bike into something almost brand new. So I ordered all the parts between Amazon and eBay and they should be in within the next week or so. A lot of knock off stuff, but for his current level of riding I’m not worried. Less of a performance build and more to test his true interest.
But I also want to do a few things that can make it a fun pit bike for me too, especially once he grows out of it. The previous owner had switched wheels to one with a disk brake, but never added the caliper. I’m going to mockup a mount for a Chinese caliper.
May powder coat frame, and might swap front forks and triple clamps so I can have disk front brakes too. For an extra $350 I can have new wheels, forks, and shocks with disk brakes on both ends. But that’s yet to be determined.
I always hated working on my bikes when I raced, but now I’m totallyI
excited to work on this for my little guy!
Going with white plastics, black tank, red seat, and maybe black wheels.
Basically for a $500 investment I could turn this old bike into something almost brand new. So I ordered all the parts between Amazon and eBay and they should be in within the next week or so. A lot of knock off stuff, but for his current level of riding I’m not worried. Less of a performance build and more to test his true interest.
But I also want to do a few things that can make it a fun pit bike for me too, especially once he grows out of it. The previous owner had switched wheels to one with a disk brake, but never added the caliper. I’m going to mockup a mount for a Chinese caliper.
May powder coat frame, and might swap front forks and triple clamps so I can have disk front brakes too. For an extra $350 I can have new wheels, forks, and shocks with disk brakes on both ends. But that’s yet to be determined.
I always hated working on my bikes when I raced, but now I’m totallyI
excited to work on this for my little guy! Going with white plastics, black tank, red seat, and maybe black wheels.
So current new parts list is;
Crank
Rod
Main bearings
Cylinder
Piston
Rings
Head
Spark plug
Cdi/spark cap
Throttle assembly
Carb
Oil injection delete plate
Handle bars
Grips
Triple clamps
35mm forks
Black Wheels front and back
Disk brake set up front and back
Chain and sprocket
Shifter
White Plastic kit including tank and seat
Air box
Bolt kit
Graphics
Had to modify swing arm to create a brake stay, but came up with something pretty easy.
Took it down to frame and swing arm and them gave it a good soak in a bath tub of degreaser, scotch brute and a tooth brush, sanded down edges on chipping paint, then etching primer, wet sand, and gloss black. Was going to strip it, blue up the welds, and then clear it, but with the new paint stripper after they handed the good stuff I was worried it would end up being a mess.
I pray I don’t find any other cool toys for this thing because my wallet can’t afford it! Doing a split and seal this week on motor and then it will start going back together.
The Shop
Also ended up having to order front and rear axle bolts, twice. First set were way too long. Somehow the front and rear got separated despite ordering at the same time, so I’m waiting on the rear currently. Also had to open up the hole in the swing arm for the bigger bolts.
Stickers got here today. Both the stickers and plastics were eBay cheapies, so I’m not sure who was off, but they fit a little weird and they only cover like half of the side plates and seam small on the front and rear fender. If the front number plate wasn’t perfect I would have said they were for the 50 not the 80. Still looks decent thought.
Most of the roller is done. My little guy has been out bouncing on it. Cool seeing it come together. Wait on my dad to finish the engine. Did some cool coatings on that. Still debating exhaust. I can’t find any good aftermarket stuff online so I make just paint it back to black(previous owner rattle canned everything silver.)
Have had a lot of head scratching moment and had to stretch my brain muscles retrofitting a lot of this non pw parts onto this, but I’m really happy with how it’s turned out so far!
Little guys birthday was last week and he’s been itching to ride so we went to the track today with just front brake. He’s just getting started, only had an electric bike before. Rode mostly in the pits and a little in the track. We haven’t had done anything motor wise to make it faster, so it’s pretty slow, but I think that’s good for him right now as it’s not as intimidating.
Also had my head scratching. Runs for like 10 minutes without issue. Then randomly shuts off. Kicks right back over. Runs for 20-30 seconds and shuts off. Usually we would do that 3-4 times and then push it back. Let it sit for 20 minutes and then it will run for 10 minutes again. I have no clue what’s up. I was thinking maybe clutch overheating, but then it shouldn’t start right back up and run fine. Anyone have any ideas?
I had one of those that always ran terrible. Did you stop the oil injection and just use premix? I heard they helps it run better.
We deleted the oil pump and running pre mix. It sounds good and runs good(just slow), but it just shuts off after it gets hot.
How did you trimm the seat
Hi,
this thread was really interesting and hugely inspiring. I’m planning doing something very similar to my old PW80 which I’ve had for about 30years (it was my 1st bike that I got when I was 7). I thought about using pit bike parts for upgrades, so it’s great to see that it’s already been done and works. Can I ask I few specific questions?…..
what wheel size did you go for? Standard 14” front and 12” rear?
can you go into a bit more detail about getting the forks to fit the PW head tube? What additional parts were required?
you mentioned that the forks were a bit too long. What size are they and what do you think would be better?
sorry for all the questions. I love what you’ve achieved and just want to do my old bike justice. Your sons a lucky kid.
zander
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