Crosscountry Question

[snacob14]

whatsup guys, here's my question. I went riding this weekend with two guys on very well equiped trx450rs. It seemed like I was shot way before them. I don't remember getting this tired riding before. I am new to the 250r. I have a 400ex and a 04 450r. It just seemed like this thing was dragging me around everywhere I went. Is there anything you guys are doing to smooth out the power on these bikes. Is there anything even possible to do to help with the big hit. I'm running a fatty pipe. I haven't checked my gearing, but it does seem high at times. I hit 4th and its useless unless I'm tapped out in 3rd.

Any help would be appreciated, I really want to run this R in my series here, I just worried its going to work me over.

[rustyATV]

An FMF Fatty pipe is more of an MX pipe, if I recall. I used to have that when I first got into XC racing and it was miserable.

I use a Paul Tuner Type 6, which is a very smooth and torquey pipe.

There's also an epoxy trick you can do on the ports to help the low end, but that gets into porting and you might be better off letting someone else do that.

My gearing is stock; 13:38

[atvmxr]

do they make exhaust stuffers anymore? LRD used to have some that was supposed to help low-end, but that was 15 years ago...

[rustyATV]

Exhaust Stuffer? This sounds like a "crutch".

[LONG-ROD]

I am not 100 % sure cause I have not tryed it but on motocross bikes pre 4 strokes they ran fyywheel weights to give a more 4 stroke feel to the power band.

[brymillen]

rustyatv, what about this epoxy trick, iv never heard of it, what does it entail?

[MossboysRacing]

I run a fmf fatty exhaust on my R and i like it. But i also run a ricky stator lightened flywheel and aftermarket reeds. I know the heavier flywheel gives more low end "feel" but i personally like the faster revving with the lighter flywheel. Also a good set of aftermarket reeds help a lot. When i first started racing XC the pipe alone what give too much of a Hit. With changing reeds and flwheel, i now have more overall power without the Dramatc Hit, and it pulls very strong and predictiable. Im gonna assume you are going to run the OXC series because i see your screen name on their forum. I usually am the only 250r their, so u cant miss me.

[rustyATV]

Originally posted by brymillen
rustyatv, what about this epoxy trick, iv never heard of it, what does it entail?

I don't have any good pictures to show you what I'm talking about and Eric Gorr long since took his reference off his site, but there's a place on the secondary ports where the intake "hooks". You can see it on the tops of used pistons as sharp, exceptionally clean areas on the intake side.

The "epoxy trick" removes these hooks by filling the the back wall of the ports so that the secondaries are aimed right at each other, instead of towards the center of the cylinder. This, combined with a 1/2 degree increase in the height of the secondaries, greatly improves low end power.

I used to race an 88 cylinder that had a little flow work, 185psi of compression, but no other port changes and it was an awesome woods motor. It was down on overall power but I could get off the line quickly and give it steady throttle on the course and focus on dodging trees and changing gears. Friends used to think I ran the whole track in one gear.