Tires, how big can I go?
 

I'll soon be shopping for some tires for the Trailmaster 300. I've noticed a few owners here going up to 23in rears. In shopping, I've seen 10incers (rim size) up to 25 or 26. Would these taller tires fit the buggy, fender clearance isn't an issue. What about the effect of such a tall tire on drivability. What kind of issues will I run into (sprocket, clutch, variator)?
Any input would be appreciated!

I think you're somewhat in guinea pig territory with the TM 300. 23s are about the max a 150 gy6 can handle, and it should have some mods to help it handle them. Your 300 would likely be ok at that size in stock form, bigger and the same as the 150 applies ...

Just remember the taller the tire, the more low end power you need to turn them and it'll be slower to get going but have a faster top speed. Clutch & belt life would be the concerns and you'll want to mod the variator to stay in the lower range longer. Easiest way to handle the increased size would be to go with a larger axle sprocket or smaller drive sprocket.

Yeah. Other than a Uni and a rejet it's still stock. I haven't gotten into the variator and clutch mods yet. I figure a bigger sprocket at least would be needed. I'll probably just have to see how it goes. Most of my riding is more flatland than climbing.

I would keep them at 23". 25" will work but keep in mind these engines stock do not have much power to spare when going with bigger tires. You can retune the CVT to compensate but you are only putting a band aid on what needs stiches. Tuning the CVT or sprockets without increasing engine power is like borrowing from Peter to pay Paul.

Yeah, that's what I was wondering about. I'm concerned about setting up a chain of "weak links". 23s are a lot cheaper than 25s as well.