Best "mini" pipe ?

[RanMan]

Ready to put pipe on my son's '02 YZ85. The only ones I can find that offer it in his size is FMF Fatty and Pro Circuit Factory. Which gives the best low end? Doesn't even have to be one of these brands. I just couldn't find anymore. Gonna use factory silencer for now.

 

[ktmdad]

The Doma pipes work well. Good overall performance.

 

[kstarr87]

I have a 02 rm85 and i have a fmf fatty and a power core2 silencer on it and i gives a lot of low end.

 

[RanMan]

Where did you find the FMF fatty? I looked on the FMF web page and I thought the "fatty" pipe was for higher rpm's. At his point, I'm not sure what I looked at because I've searched through so many sites. Thanks forthe reply. I will look again. Thinking about keeping stock exhaust though. Would this be bad? Supporting two bikes and two riders and both racing has the pocket book a little thin.

 

[yzer67]

No its not bad to use stock pipe.

 

[lwsmithjr]

You didn't say if your son new to racing. If so I would send the cylinder off to Eric Gorr for a "low to mid" port job. It's less expensive than a pipe, and more effective. I did not do this with my son and it took him most of a year to learn to keep the thing on the pipe. (He rides a CR which has no bottom and an expolsive hit.) Eric will even enhance the port job within a year for free. If he's not a rookie, go with the mid and up port job. If you are intent on the pipe, go with the Fatty and a V-Force reed valve. It will rip. We have kid's riding 80's in the Youth Class (80 -125cc, 12 - 15 yrs.) hanging with the 125's using this combo.

 

[MikeS]

agree with lwsmithjr

Porting is the best answer, the YZ and CR are dead down low and not easy to ride. A pipe is just a bandaide IMO.

For our RM the Delta II was a big plus with a doma pipe silencer combo. Sweeeet midrange.

 

[BENT]

Everyone just answered questions i had on mods for my CR 80 that i have been wondering about for years.

 

[RanMan]

My son races harescramble type stuff. He does well on it. Has done good about staying in the pipe. Just trying to find a way to make it a little easier on him because some of the stuff gets knarly and nasty. Sometimes he even rides the same course I do. He was in one is S.C. at the Little Brwon Jug enduro and the juniors race was one single track 18 miles long. It was a challenging course even for some of the adults. Anyway, thanks for all the info. Just have to weigh it all and see what the pocket will allow.

Oh yea, do you think gearing it down wil help any? Stock is 14/47. I just ordered 13/48 combo. What can I expect from this?

 

[lwsmithjr]

It will definetly help with hills, mud, tree crossings, ect. He will get into the power much quicker (the change you are making is roughly 10%). What we discovered in gearing the bike down that much with a close ratio transmission, it seems to run out of gear in a hurry. In other words, the power band seems narrower, even though it's not. It also causes the throttle to be more sensitive to rider input. Sometimes thats good, others it isn't!

I was assuming you guys did MX. Knowing that it's harescrambles, I would more strongly recommend the port job. He will lose some top-end, but my experience has been there are very few kids riding 80's that can use all the power they make anyway. I don't think anyone will be able to run off and leave him in the environment he's racing in. Besides, if you don't like it, Eric will redo it. Since the YZ and CR don't have power valves, there aren't many choices to increase low end power. I recently saw a dyno chart that compared all of the minis and was amazed at the difference in the shape of the curves. The KX and RM make about 12 HP @ 8000 rpm. The YZ makes around 10 and the CR only 6. They all peak in the 17.5 to 18.5 range.

I just noticed you (y'all) are from Alabama. We are in the Birmingham area.

 

[RanMan]

We are from Anniston. We need to hook up and ride. Met another guy from B'ham Sunday at Maplesville. We are gonna try to ride Kentuck sometime. You should join us. Not sure when though. You know any good places?

 

[lwsmithjr]

There used to be a lot of good places, but just like everywhere else, it's becoming less and less. We've been to Kentuck several times and really enjoyed it. But, that brings up another pipe issue. That's part of a National Forest and our racing bikes don't have spark arrestors. Like you, our pockets are only so deep and it's difficult to cover all the bases. I hate to admit it, but I didn't even realize we were illegal until some guys we know got run off for not having spark arrestors. Once we found that out, we haven't been back.

There is a motocross track in Pell City (Mill Creek) that hopes to open a harescramble track in the next couple of years. But for the time being, power lines and gas lines have been our only alternative to the track.

Lets try to hook up. Our racing season is over in a couple of weeks. My email is [email protected].

 

[Kerry Shane]

I have used the pro C pipe first and found better results from bottom to top with FMF Gold series SST.