Does getting a 2-stroke drastically ported have any side effects, such as harder cold starting, and less reliability?

 

By drastically I assume you mean an aggressive port job. Usually this a top end setup best used for dragging and duning. The start up usually isnt a problem, at least not from porting. Higher compression will make the bike harder to start though.

Anytime you dip into the engine and increase performance it typically decreases reliability. A proper quality build with good components should last a pretty long time with proper jetting and warm up. But when you go hi-po you will decrease the engine life and rebuilds will be more often.

 

Thus you get the old addage of "pay to play". More fun means more money if not right now then down the road a bit. If you get the cylinder done by someone who actually knows what their doing then you wont have issues. Many people run ported cylinders and get good life out of them.

 

I had a 250r 330r Duncan motor ported and it ran great. It was a little bit touchy with jetting but once you have that down you are good to go. Makes a big difference in power also.I would not go radical if you are going to trail ride it. Some port jobs are designed for wide open throttle and do not fair well in slower conditions.