I have always had stock bikes and although I knew my first moped (a 50 cc) in and out, I never got down to fixing the bikes myself (unless it was a real small thing like fixing spark plug

) I alawys wanted to build a custom. Cafe Racers have recently taken my attention
Reading through some projects which people have done Honda from 1970's and 1980's are very popular these days as base biked because of reliability, good inline fours and they are cheaper than traditiona cafe racers like Triumph and stuff.
Since it would be my first project,I plan to start with a small bike. I think I will go for something like CB 175. Its a twin. I was also looking at Honda Rebel but it has higher handle bars and the forks are longer too. I believe I will be able to install new forks with lower height and give the bike a more cafe look but then in the beginning I want to avoid costs of forks etc. I will install new tank, re do the engine, and install cafe like seats and handle bars.
What would be a good place to learn how to enhance the performance of a twin 4 stroke. Also would like to have help of you guys.
If we change the carbs, how is the timing set for new ignition cycle and stuff. I know it will be done using timing chain but how to you test it and everything.
I will have more questions. I hope to get some replies to them.