monkeyinfantry
New Member
Hey everyone, and welcome to my 1980 SR250 build. I picked the bike up on a whim on the good ol’ Craigslist one day. I saw the post for it near me, $250 and it was going to be scrapped for metal if no one was going to come pick up in a week. I saw the pictures of the bike and they said “Save me!” so I grabbed my trailer and straps. I figured it was a good price for a frame with a clear title, has the engine, and fully rolling. The seller has the sister bike of mine; he was given my bike for free as a parts bike when he bought his. I’m no stranger to projects or fabrication so it seemed like a fun little build to take on.
Here she is the day I brought her back:
Tear down and assessment: she looked pretty rough, but not the worst thing I’ve ever seen
Stripped the swingarm with some aircraft stripper and primed, it was the rustiest/largest part
Disassembled the rear wheel, polished up the spokes which surprisingly took a lot of effort to get nice and shiny again
Took the engine out of the frame, disassembled the top end. Piston is in good condition, had some soot on it that was cleaned off, she was running very rich. The rings were stuck on so I busted out the heat gun to pop them off. The cylinder had the tiniest amount of rust where the piston rings were in contact with the cylinder, but after cleaning it up It looks like I may be able to get away with just a hone job, Ill assess this more when I get new rings and such. Regardless, I think I’ll reuse the piston as it still looks mint even in the ring slots, just need some new rings, pivot pin, and circlips.
I bought a café seat from China off Amazon, I didn’t like how it was going to sit on the frame, so I chopped it to make the subframe straight. I don't plan on going full cafe style, I'll probably end up with some sort of drag bar or ultra low road bar.
My bike didn’t come with any keys, there wasn’t even an ignition switch on the bike. So I decided to bust out my lock picking skills to open the tank. After about 2 collective hours of tinkering with it, the entire tumbler popped out of the hole! I put a large screwdriver into the hole and twisted, and she popped open. It’s rusty, but not the worst I’ve ever seen. I bought a new gas cap from China off Amazon and it looks like it should work perfectly.
I was sitting on the frame and realized how flexible the frame was so I decided to add some reinforcement gussets, they may be a bit overkill but they look cool I’m also going to touch up some of the stock welds, they look pretty lackluster.
Next was tackling how the gas tank mounts in the rear. I was going to just make use of the rear mount that was already on the tank, but it interfered with the seat so much that it did not look good at all. So my plan is to chop off part of the old tab and use it to make a tab that goes straight down to the frame instead of the odd arch, so I could get the seat as close to the tank as possible. I cut the tab in half and that’s when I realized that welding on a gas tank may not be the best idea!
So this is where I’m sitting currently, I’m doing research on how to properly clean a gas tank to prep it for welding, but honestly I’m getting mixed answers all around. Some people are saying just buy a new tank and making it sound like we are dealing with an atom bomb, and other people are saying just use water and dish soap multiple times and you’re good, like it is no big deal. I do have a few gas tanks I’ve been looking at, but I think I’d prefer to use the one I have. I won’t be welding on the tank itself, but it's on the part of the old tab which is damn near close to a seam of the tank. Anyone have tips for doing this and not blowing up my garage and face?
In the meantime, I’ll be working on reinforcing the frame more and I’m going to start disassembling valves. Do any of you SR250 peeps out there have a good method of removing the valve rocker pivot pins? They say thread an M8 (I think) into them and they should slide right out. First off I can’t find a bolt that threads into these, are they fine threaded?? And of course, they don’t just slide right out, the bike has never been opened before by the looks of everything. Any helpful tips?
Sorry about the varying quality of the pictures, I got a new phone mid build and they improved significantly. There could be many more pictures, but I think this is enough for now. I hope you enjoy my build!
Here she is the day I brought her back:
Tear down and assessment: she looked pretty rough, but not the worst thing I’ve ever seen
Stripped the swingarm with some aircraft stripper and primed, it was the rustiest/largest part
Disassembled the rear wheel, polished up the spokes which surprisingly took a lot of effort to get nice and shiny again
Took the engine out of the frame, disassembled the top end. Piston is in good condition, had some soot on it that was cleaned off, she was running very rich. The rings were stuck on so I busted out the heat gun to pop them off. The cylinder had the tiniest amount of rust where the piston rings were in contact with the cylinder, but after cleaning it up It looks like I may be able to get away with just a hone job, Ill assess this more when I get new rings and such. Regardless, I think I’ll reuse the piston as it still looks mint even in the ring slots, just need some new rings, pivot pin, and circlips.
I bought a café seat from China off Amazon, I didn’t like how it was going to sit on the frame, so I chopped it to make the subframe straight. I don't plan on going full cafe style, I'll probably end up with some sort of drag bar or ultra low road bar.
My bike didn’t come with any keys, there wasn’t even an ignition switch on the bike. So I decided to bust out my lock picking skills to open the tank. After about 2 collective hours of tinkering with it, the entire tumbler popped out of the hole! I put a large screwdriver into the hole and twisted, and she popped open. It’s rusty, but not the worst I’ve ever seen. I bought a new gas cap from China off Amazon and it looks like it should work perfectly.
I was sitting on the frame and realized how flexible the frame was so I decided to add some reinforcement gussets, they may be a bit overkill but they look cool I’m also going to touch up some of the stock welds, they look pretty lackluster.
Next was tackling how the gas tank mounts in the rear. I was going to just make use of the rear mount that was already on the tank, but it interfered with the seat so much that it did not look good at all. So my plan is to chop off part of the old tab and use it to make a tab that goes straight down to the frame instead of the odd arch, so I could get the seat as close to the tank as possible. I cut the tab in half and that’s when I realized that welding on a gas tank may not be the best idea!
So this is where I’m sitting currently, I’m doing research on how to properly clean a gas tank to prep it for welding, but honestly I’m getting mixed answers all around. Some people are saying just buy a new tank and making it sound like we are dealing with an atom bomb, and other people are saying just use water and dish soap multiple times and you’re good, like it is no big deal. I do have a few gas tanks I’ve been looking at, but I think I’d prefer to use the one I have. I won’t be welding on the tank itself, but it's on the part of the old tab which is damn near close to a seam of the tank. Anyone have tips for doing this and not blowing up my garage and face?
In the meantime, I’ll be working on reinforcing the frame more and I’m going to start disassembling valves. Do any of you SR250 peeps out there have a good method of removing the valve rocker pivot pins? They say thread an M8 (I think) into them and they should slide right out. First off I can’t find a bolt that threads into these, are they fine threaded?? And of course, they don’t just slide right out, the bike has never been opened before by the looks of everything. Any helpful tips?
Sorry about the varying quality of the pictures, I got a new phone mid build and they improved significantly. There could be many more pictures, but I think this is enough for now. I hope you enjoy my build!