Fly wheel weights on a MC250

[MikeB]

I wasnt sure if I should put this question in this section or the drivetrain section. But I figure more people look at this section.

First off for the background information. I have a 99 MC250. I use it for trail riding and hill climbs. As many of you know it only has a 4speed. My gears are 13/50. I find the gear ratio to be to low for a 4 speed.

If I install a heaver fly weight will this help the lowend enough to run a higher gear ratio? I have wanted a 6 speed but I dont have the money.

Can you really tell a difference with a heaver fly weight? The MC250 reves to the sky in half a second. I contribute this to the light fly wheel. Is this correct thought?

MIKEB

 

[GMP]

You can do two things. First you can add a weight to the flywheel, very easy. I like the 14 oz. Also on the MC, there is no primary weight behind the crank pinion like on the EC/DE/XC, just a small spacer. You can add this as well. '99 and '00 used a 10 oz,. round weight, later bikes use an 8 oz eccentric weight that acts like a balancer. The newer 8 oz. weight can be added to the older bikes (250s and 300s).

If you only go with a flywheel weight definately go with the 14 oz.

 

[MikeB]

Thanks for the information.

I just wonder if I put on the 14oz weight if it would help with the gearing?

MIKEB

 

[GMP]

I imagine what your trying to do is avoid stalling when you gear the bike taller. The weight(s) will definately help, as will good jetting off the bottom, and a good, light trans oil like Rotella 5W-40W to minimize clutch drag.

 

[MikeB]

Thanks for the infomation. Thats exactly what I need to know. I do use Rotella 5W-40W. It works great. I also have a LTR jetting kit. So I should be set.

Thanks again.

I think I will try it out once I get done changing my fork seals.

MIKEB

 

[mattmax]

I don't know if this helps you at all, but my experience with weights was on a 16oz on a CR500. At low speed, it made no difference, but 3rd gear or above, it kept the front wheel on the ground more and better traction at speed on slick surfaces. I've been tempted to take it off since the only thing I put it on for was to have more woods traction, but the low end torque overcame the weight. I just ordered an 05 MC250, so I'm interested in what you'e weight does for you.

 

[MikeB]

Thanks for the information. Thats what I was afrade of. I need it for the low end. I have ridded a cr500 and have never needed to go above 1/4 throttle in the woods. Its a crazy fast bike. Good luck with the new MC250 they are great bikes. They feel very solid compared to the other bikes I have riden.

 

[mattmax]

weight on MC250

Thanks for the information. Thats what I was afrade of. I need it for the low end. I have ridded a cr500 and have never needed to go above 1/4 throttle in the woods. Its a crazy fast bike. Good luck with the new MC250 they are great bikes. They feel very solid compared to the other bikes I have riden.

I tried to post something last night, but maybe I forgot to hit "submit reply"
Just because I had no luck with my CR500, doesn't mean it won't work for you. The stock CR500 has a very hard to control low end power delivery, especially on slick surfaces. I just had an Eric Gorr port job, which is supposed to smooth out low end power and also boost HP and increase Rpm overrev. He also recommended a PWK carb, as opposed to the inferior PJ that was on it because the PJ has poor power transition from idle, to 1/8 to 1/4 throttle. That was the first thing I noticed when I bought the bike(plus the incredible midrange hit). I still haven't finished the jetting, so I don't know if there is any improvement.

Everyone I've heard of running a 250 motocross bike in the woods seems to benefit from the flywheel weight, but you'll probably lose some of the quick revability that bike has if I noticed it on my CR.

MY MC250 deal fell through. The guy never shipped the bike and I don't think he ever had one. I've been haveing lots of people recommend I go with the EC250, and if I don't find it powerful enough, the motor can be converted to the MC motor without a lot of trouble. I've always been a power freak, never finding a bike quite as fast as someone else says it is. I've heard the MC has a lighting coil, but it's not hooked up. If this is true, it would actually be easier and cheaper to put lights on the MC, then make a DE an MC. Do you know if it does and do you have an opinion on this. I've been trying to buy a new bike since February, 3 deals fell through, and I'm ready to buy a bike yesterday.

Matt