2 stroke people!!!

[Johnpewpew]

So i have this winter project that I'm getting into. Its a 1975 yamaha dt250. The plan is to turn it into a cafe racer. One of the things that will be done is an engine overhaul. While the engine is apart I was thinking of going bigger. Right now its 246cc. Wiseco make a 2mm over piston so I can punch it up to 253cc. As of right now the motor runs. One or 2 kicks and it starts. So the question i have is. Will it be worth it? Will there be a noticeable HP gain?

[Kurlon]

It won't be a massive gain, but will flatten the power curve slightly, more low/mid while loosing some overrev. If you want to perk it up get the head reshaped and the cylinder ported, and find a good pipe for it.

[breakdirt916]

old 2 stroke?

have you guys not learned from my adventures?

I guess it's okay if it's just around a backyard

trucked 2-1/2 hours to a riding area and it was fine in the parking lot, but wouldn't run the rest of the day and we couldn't figure out why

[Johnpewpew]

old 2 stroke?

have you guys not learned from my adventures?

I guess it's okay if it's just around a backyard

trucked 2-1/2 hours to a riding area and it was fine in the parking lot, but wouldn't run the rest of the day and we couldn't figure out why

But isn't that part of the fun of owning an old 2 stroke.

[Johnpewpew]

It won't be a massive gain, but will flatten the power curve slightly, more low/mid while loosing some overrev. If you want to perk it up get the head reshaped and the cylinder ported, and find a good pipe for it.

Do you know of a good shop to do this work?

[Kurlon]

I've gotten work done by Eric Goor and Kustom Kraft, there are LOTS of two stroke tuners out there though so I'd say google around and see if any specifically mention working on the DT250?

[Road_Clam]

So i have this winter project that I'm getting into. Its a 1975 yamaha dt250. The plan is to turn it into a cafe racer. One of the things that will be done is an engine overhaul. While the engine is apart I was thinking of going bigger. Right now its 246cc. Wiseco make a 2mm over piston so I can punch it up to 253cc. As of right now the motor runs. One or 2 kicks and it starts. So the question i have is. Will it be worth it? Will there be a noticeable HP gain?

I've restored a '73 Kawi H1 triple, and as for a 2mm overbore, I advise you not to do it thinking you will see performance gains. You won't notice any hp increase. What I would advise is to "save" the bore to allow a future overbore "if" you ever experience a top end failure. (strictly just my opinion) .

[Chippertheripper]

My dad had a 70’s dt250 that I rode the piss out of when I was 13. It was the first time I went 80mph on a motorcycle.
Anyways, BE CAREFUL when you kick it, it WILL kick back, and it might hurt you.