A friend has an 02 375 which is why I bought a new 03 400 because it is the same motor. I thought my power was a little low but attributed it to not being broken in yet. I have 120 miles now and just rode his 375 again. Wow, he has much better throttle response and low end acceleration. He gets a couple miles per hour better top speed,too, and it gets there quicker than mine. Is there any explanation for this?

I've read a couple of posts about different dealers adjusting the carb different. Is there some adjustment I can makemyself? I think these machines use the same 376cc motor but have different carburetors thouhg.

 

I don't know if this would contribute anything, but they have different rear ends, too. The '02 375 has an ACT suspension in the rear while your '03 400 has IRS. This may contribue some additional squat to your machine which could affect your accelleration.

But then, that's only a guess.

Otherwise, I believe the motors are identical. Is your 400 an auto or a manual?

 

Yah the different suspension system will affect your acceleration, the IRS will sit down some and the IRS is not as efficient as a solid rear axle to get the power to the ground, but the difference is minimal because the HP is minimal, if you were talking 1000 hp dragsters, big difference.

Also does he have a manual? or Auto? Same goes for you? The manual will feel more peppy.

 

Sorry, I left that out. Both machines are autos.

 

With 120 miles on your bike yours is still breaking in, Have you had the first service yet, if not that will make a difference. Once they set your valves and you get a few more miles on it should improve.

 

yeah, its not broken in yet, my 01 250 4x4 Cat seems like every year it gains a little more power................