I have a stock 250R with a FMF fatty pipe and Powercore II silencer, but I want more bottom end, once I get in the power band it rips but I was wondering if a reed spacer and a set for tourque reeds would help this?

 

I got the exact same problem.

I dont think that a 2stroke will have a bottom like a 4stroke, all the articles I read say you gotta feather the clutch and what not to keep the power on. I just try and get the power band on before shifting, like rev it high before shifting so I am still in the power once I hit hte next gear.

 

The think is I just rode my friends stock 250R and it has more power than mine on the boittom I never really revved it out to see the top end though. Could it be because the top end hasnt been done for awhile?

 

up your compression, it is one of the cheapest bangs for the buck. but keep it under 180psi for 92octane.I have heard reed spacers work but will probably help top end only since you are lowering the crankcase compression,and when you do that, it will give you a weaker signal back to the reeds.v-force reeds have a adjustable reed tension that can be set for low end, the RAD valve is still a excellent choice too. I own both and have not seen a major difference, but will be dynoing both to see which has a slight advantage. You can also go with a larger rear sprocket try 1 tooth (or 2 teeth if you have paddle tires in the sand),this will take top speed away though.The only other thing would be carburation, If you are running fat it will lose a lot of power.you will want your plug a light tan, the best way to check plug color is to find a long straight away and do a full throttle speed shift pass and while still at full throttle hit the kill switch and hold the throttle wide open until you roll to a stop.Then pull the plug and check coloring. This also works for checking the needle, do everything the same except hold the throttle half way. The reason you do this is so your are isolating different fuel circuits in the carb, if you were to have your idle circuit to rich but the needle to lean and let the bike idle for a lenght of time the plug would be dark and you might lean down even more causing a melt down. One other thing always mix your fuel at the same ratio because adding extra oil to your premix will lean down the air-fuel mixture or adding less will richen your air-fuel mixture this can cause extra headaches in trying to jet in your motor.

 

would a CR 250 head gasket up the compression any?

 

Yes, an 89 CR250 head gasket is much thinner than a stock TRX gasket. You can also take apart your stock 3-part gasket and use one of the thinner pieces. Get some Permatex(sp?) spray on copper and coat both sides before installing. You can use the head gasket over and over this way. I have used mine 3 or 4 times and have not had a problem yet.
ERIC

 

Hey Kybol;
I just went redid my stock 250R motor last week. I put a CR head gasket on ($19.95) along with a wiseco +.25 piston and the compression went to 193 psi. After this, it was suggested that I run race gas. I broke it in with 93 octane and Klotz R50 32:1 and then switched to 100LL Aviaton gas (2.09 p/gal) and R50.

I also put on a FMF Fatty and PCII silencer and an outerwear cover instead of the plastic cover. The Fatty pipe inlet doesn't fit perfect with the exhaust flange, it is leaking a little bit of air, but not much. Also, the pipe rubs the a-arm bracket which I will have to modify as well as the AC propeg nerfs (rub point there as well).
Just letting you know if you plan on any of these parts.

It improved bottom end (I am still jetting the low end) but the mid range is a handful! Since I race woods, I would rather have a little different pipe, but this is definately explosive.

 

My pipe rubs too, how did you fix it?

 

adams 44, you may need a new exhaust ring and gasket if your pipe is leaking. Did you also fit the ring to the pipe like the instruction suggested. of all the pipes I have owned the FMF pipe has the nicest exhaust flange, theirs is machined perfectly round compared to a stamped sheetmetal end on everybody else. On my 88 250r chassis I have had no problems so far with any rubbing.

 

Hey Rsss396...no I didn't file off .010" of the exhaust ring, but I do have a new flange gasket. It is definately leaking out of the exhaust ring. It seams to not mount on quite straight, which is just enough to bring it close to the upper right rear arm mount. I have a piece of wood inbetween it right now. Also, it is rubbing on the right front nerf mount.

Did you use the rear stock silencer mount on the right front motor mount for the Fatty mount?
This is what one of the info sheets said to do.

(I received two, one says to do this, the other says to keep the stock mounts in their original positions, but that would work).

Any help, I would appreciate it.

Thanks, Nick