Well, I finally put the bike together and did the first start. I bought this bike in barely running condition, so it was pretty cool to see it up and running. I tuned the carb and is starts very easy and idles nicely. It has great power now and quick throttle response.
The bike specs are:
1982 Honda NU50 Urban Express
PHBG 21mm Race Carb
I few problems I noticed are:
1) an air leak, which I initially thought was the exhaust, but now think it is the gasket between the cylinder and the head. The exhaust is very tight and feel air coming between the head. I reused the stock metal gasket. I would to like to put a gasket similar to the cardboard one from the block to cylinder. I'm guessing the head might be a little warped and need to be milled or a thicker gasket installed. Anyone know where can I get a new gasket?
2) The throttle cable is now too short and since I deleted the oil pump, it has an extra cable which is not used anymore. The weak-ends intake stretches the carb a few inches out. I had the line hooked up to the bike, but whenever I tuned all the way to the left, the throttle would go fully open. Where is the best place to get a single throttle cable the right length?
3) I took it for a ride and it has some awesome low end power now up to about 20 mph. I wasn't nailing it (still on break in), but couldn't get any more speed. It was like it scooted to 20 mph then hit a wall. I haven't changed the belt (Ax31), clutch, or the variator weights yet. I'm guessing the problem is with either of those. The belt looked fine upon inspection, but I haven't looked at the weights yet. Any ideas?
I can't wait to drive this thing when it is all working properly, but it needs some further tweaking. I don't know what people were thinking when they say the weak-ends exhaust is quiet. It's about twice as loud as the stock exhaust on throttle. I still think the power is going to be worth it! I am so used to driving a stock NU50 and getting honked at and driven off the road constantly. Now it should be a little easier! Thanks for any help.