Moa
Been Around the Block
Time to update the front page with the progress so far:
What we have here is a 1987 Honda NSR250 MC16, the MC16 was the first of the popular, but somewhat rare (depending on where you live) NSR series. The design of the bike borrowed heavily from the World Championship winning 250cc machines of previous years, and is full of GP inspired tech.
This particular bike has a later 1989 MC18 series motor, which has a much greater tuning potential over the MC16. These motors make around 55-60hp in stock unrestricted form, and the whole machine tips the scales at a featherweight 125kg dry.
The build will be done in two phases. Phase one will be restoring the bike to as new mechanical condition. There will be a few changes to stock parts too, but at this stage it's mainly just a rebuild. Then I can get it back on the road and enjoy all of its smokey goodness while I plan phase two.
[UPDATE] The bike is now running.
Phase two is where the fun begins. I've got plenty of ideas to make this bike something special, but that's for another time. I have decided on a paint scheme however. Here's the latest mock up:
[ORIGINAL POST]
So I picked up an NSR250 mc16 (1987 I think) for 100 bucks! I wasn't sure what to expect from it, but at $100, it was a steal.
Here it is the next day stripped down:
The engine wouldn't turn over when I got it so had a peek down the spark plug holes and through the reed valves. There was a layer of sludgy water in the lower cylinder, and a bit of rust inside the crank case. Anyway I pulled the engine out and took the heads off. It looked like the sludge just spilled into the cylinder from the exhausts when I tipped the bike on its side, as the chambers were full of water.
The carbs, cylinders, heads, pistons, and reed valves were all taken off and given a good cleaning. It turns out the pistons weren't seized.
The heads look good, some slight detonation marks on the upper cyl head.
Lower cylinder looks OK too.
As for the upper cylinder and piston, there's quite a bit of scoring on the sides. I've never rebuilt a two-stroke before but I'm pretty sure these look like they can't be re-used. They're Nikasil plated cylinders too, which wont be cheap to re-bore/plate.
Here's the bottom end.
Doesn't look too good inside. Hopefully, the crank can be salvaged. I'll pull it out when I get a flywheel puller. The crank only turns a few degrees, then locks up, I can't figure out what could be causing that as it doesn't feel stiff when it turns.
Apart from moisture getting inside the engine, the bike looks reasonably good mechanically. I would love to get this bike running again, but if it turns out to need too much work I'll have to just part it out, make some money, and get another two stroke project!
What we have here is a 1987 Honda NSR250 MC16, the MC16 was the first of the popular, but somewhat rare (depending on where you live) NSR series. The design of the bike borrowed heavily from the World Championship winning 250cc machines of previous years, and is full of GP inspired tech.
This particular bike has a later 1989 MC18 series motor, which has a much greater tuning potential over the MC16. These motors make around 55-60hp in stock unrestricted form, and the whole machine tips the scales at a featherweight 125kg dry.
The build will be done in two phases. Phase one will be restoring the bike to as new mechanical condition. There will be a few changes to stock parts too, but at this stage it's mainly just a rebuild. Then I can get it back on the road and enjoy all of its smokey goodness while I plan phase two.
[UPDATE] The bike is now running.
Phase two is where the fun begins. I've got plenty of ideas to make this bike something special, but that's for another time. I have decided on a paint scheme however. Here's the latest mock up:
[ORIGINAL POST]
So I picked up an NSR250 mc16 (1987 I think) for 100 bucks! I wasn't sure what to expect from it, but at $100, it was a steal.
Here it is the next day stripped down:
The engine wouldn't turn over when I got it so had a peek down the spark plug holes and through the reed valves. There was a layer of sludgy water in the lower cylinder, and a bit of rust inside the crank case. Anyway I pulled the engine out and took the heads off. It looked like the sludge just spilled into the cylinder from the exhausts when I tipped the bike on its side, as the chambers were full of water.
The carbs, cylinders, heads, pistons, and reed valves were all taken off and given a good cleaning. It turns out the pistons weren't seized.
The heads look good, some slight detonation marks on the upper cyl head.
Lower cylinder looks OK too.
As for the upper cylinder and piston, there's quite a bit of scoring on the sides. I've never rebuilt a two-stroke before but I'm pretty sure these look like they can't be re-used. They're Nikasil plated cylinders too, which wont be cheap to re-bore/plate.
Here's the bottom end.
Doesn't look too good inside. Hopefully, the crank can be salvaged. I'll pull it out when I get a flywheel puller. The crank only turns a few degrees, then locks up, I can't figure out what could be causing that as it doesn't feel stiff when it turns.
Apart from moisture getting inside the engine, the bike looks reasonably good mechanically. I would love to get this bike running again, but if it turns out to need too much work I'll have to just part it out, make some money, and get another two stroke project!