Tested | Beta 350 RX Two-Stroke

Sounds like a great bike. Curious if you guys could adjust the pv, jetting, try a vhm head, really spend a little time tweaking on it.

They are I’m sure sensitive and respond to some tweaks. My tm 300 was that was, had to lean out the jetting quite a lot. Each time it just ran better and pulled harder.

Great test tho, sounds really great. Is it really 10-20 lbs lighter than many 450s?!

I rode my buddies a month ago. Feels very light. Good torque. Turns sharp(er) than I'm used to but no headshake. Little sticky on shifting though.

@Tokarski710 If you were to compare lap times to a 450 4t, how do you think they would compare? Level of effort to ride for a moto?

I have a 350 SXF and have considered a 300 2t for my next bike. 

Where did you have the powervalve set when testing?  Seems like that could have a major impact on engine charateristic and it's easy to adjust (large external hex head bolt near exhaust port).

Why did not Beta choose to have a counter balancer shaft ? 
Any inside of the development team at Beta ?

It was a very good test. Very thorough. The kid had a little trouble explaining the balance and suspension, but he did a good job. 

The bike has been out since June of ‘25, kind of odd to do a first test of it now. 

What we’re really looking for is a modified test - pipe, porting/ head mods, VForce/Boyesin reed block, Vortex ignition/black box, big bore w/ stroker crank, bored carb, flywheel weight…

Mine was a little sticky too when new, but broke in quite nicely.. shifts great now. Also, the stock shifter is too short and close to the engine cover. A longer shifter does wonders. Beta even sells the improved shift lever.

I have been tossing around the idea of purchasing/ordering the Beta 350RX. I love my KTM 350, but I'm digging this big bore two-stroke. I'm just a +40B MX weekend warrior, so I don't need anything too crazy. 

Sounds like a pipe and flywheel weight will do good things for this one.

lol, my thought was head mod and T2

I was gonna make a thread about the lack of mods done to this bike. There simply aren’t any. Nowhere on the internet has anyone reportedly done anything to it.

They didn’t even try a different needle position here, not to bash the test as it is cool to have the beta tested but that’s a shame because who knows how good it could be with a couple steps up or down on the jetting.

Big two strokes respond massively to small changes.

I guess I need to talk to Whiskey Throttle Media, MXA, Dirt Bike and ask them to do a modded build of this bike. 

vhm makes an ignition and head for the 350. Huge gains on the 250.

Ignition, head, mrx02, dialed jetting, play with the power valve…..

Vital and keefer have the best info by far. The others are just advertising.

How cool would it be if someone did all this to an RX350?

Maybe you should get one a do your own build. Then it can have the mods you want. 

Update - I emailed Pingree at WTM and he is gung ho about getting a modded test done on one of these. He said it may take close to a year to get it done, but was gonna start on it. 👍

I was surprised he even responded but we had good back and forth. Awesome guy.