T250 vs T350

[Mat]

I have a 1969 T250 that I have got running pretty well and have some fun on. I would like to get a T350 of the same year or close. I was kind of disappointed to find out the T350 isn't a true 350 but closer to a 300 at 315 or so. Is there any out there that has both a T250 and T350 or that knows both? How do they compare? Thanks for any input.

[oldjapanesebikes]

I have the Suzuki shop manual on line at this link - both models are covered in the same manual and they appear (to me at least) to be pretty much the same machine really. And yes, the 350 is just 315 cc. Basically, just larger bore, bigger carbs, larger tires and the trail is more on the 350 than the 250 so perhaps the frame is slightly different, or that's due to the difference in tires ?

[Vintageman]

If you get the Suz service manual it has performance curves for both. Yes the T350 is only a 315 but if you look at a 54 mm piston versus 61mm it is significant.

I have owned GT250s (still do) and have converted them to T305 and T350s.

There is a signifcant difference in stock power. bewteen the early GT250 (even with R250 intake and carbs) and T305/T350

At the moment my 74 has a T305 top bored 1mm over so a 315cc

My 76 GT250 is in the process of getting a 72 T350 engine.

The later GT250 has signifcant top end power (very fun), but just has no low end pull like a T305/T350.

This year I found new pistons and shaved 2mm off T305 skirt. It still has good bottem end, but the HP pivot point is now at +6000, at which point the bike has o much more power and has at least 1500 rpm more top end.

I compared porting specs bewteen a T250 and T305 and think there was at least 4 mm difference on intake where the T150 had more timing. They have same stroke. So really that T250 is tuned fairly hot I think

The T350 I plan to remove up to 2mm from skirt again and raise jug 1/2 mm and remove just a tadd more than 1/2 mm off head

Way more than you asked.

They all run good stock too