Bad vibes

[Colemanian]

When I first rode my bike 11 ec300 I noticed the engine vibes. My hands were the worst but the pegs are bad too. I kinda got used to it. Then I rode a friends ec250. Wow! It's like 4t smooth. I'm seriously considering sending my engine out to be "balanced", I know you can't really balance a single cylinder but I've read a lot on KTM talk and several guys said they loved there 300 after sending it to be balanced. What do you guys think? Anyone you know and trust to do the work?

 

[GMP]

That's what is nice about 250s, a lot less vibes.
Someone here had a crank balanced and liked it too.


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[twowheels]

When I first rode my bike 11 ec300 I noticed the engine vibes. My hands were the worst but the pegs are bad too. I kinda got used to it. Then I rode a friends ec250. Wow! It's like 4t smooth. I'm seriously considering sending my engine out to be "balanced", I know you can't really balance a single cylinder but I've read a lot on KTM talk and several guys said they loved there 300 after sending it to be balanced. What do you guys think? Anyone you know and trust to do the work?

That's what is nice about 250s, a lot less vibes.
Someone here had a crank balanced and liked it too.


Sent from my iPad using Tapatalk HD

The issue is likely this - with a single part number for the crank and the rod, either the 250 or the 300 is going to be "out of balance". In the case of GasGas it looks like the crank is sized for the 250 piston, and the larger/heavier 300 slug makes it shake more.

Without a proper counter-balancer arrangement though the best you can do is balance the forces at the top and bottom of the stroke. The engine will be unbalanced fore-aft but we as riders tend to be less sensitive to vibration in that direction.

 

[Jakobi]

My 300 used to buzz quite badly. I then went to the 250 top end which reduced the vibes noticably. Then I rebuilt the 250 and had the crank trued and its the best its ever been. You still get a few vibes but nothing like the 300. I remember on transport sections I'd feel the vibes through the pegs, bars and even seat. I used to think it was the bike every woman would want.

Another time I had one of the engine mounts loosen off and that made it vibe more too.

 

[(F5)]

my friend's 300 vibes more than my 300. Mine is similar to my 200.

Tighten all mounts etc but otherwise I'd consider a rebuild to see how straight it is. Or at least compare to another 300