Actually i think is around 263, because when i had a machinist check the cylinder, he measured it and it came out to be around 262.8something.

 

Then it isn't bored .050" over. Each .25mm is .010".

stock 66mm=246.32cc
+.25mm=248.19cc
+.50mm=250.07cc
+.75mm=251.96cc
+1mm=253.85cc
+1.25mm=255.74cc

Take the stroke and multiply it by the radius of the bore squared, then multiply it by 3.14159.

Do it in metric and you are converting to cc's so(for a stock bore)...
6.6cm X 6.6cm then devide by 2 to get radius. Then X 7.2cm X 3.14159 and get 246.32578

Maybe he was talking about the diameter of your cylinder being 2.648"

RIGHT! Not that it really matters.

ERIC

 

ESR TRX-5 vs TRX-6: what's the difference? I really like what everybody says about the TRX-5 but isn't that the one that exits the rear of the bike in the center? I can't live without an airbox - is the TRX-6 nearly as good or is it a totally different beast?

 

the TRX5 is the all around pipe and comes in both standard mount and center mount (no airbox) flavors.

the TRX6 is the mx/xc low end style pipe

 

TRX5 is all around while TRX6 is low end.
You are thinking of the center mount pipe. It depends on what kind of power you want and how you bike is set up.
ERIC

 

Yeah i think your right, maybe he said the diameter was that, and he figured that cc's you would just move the decimal. Thanks for clearing it up. But about the ESR TRX 5, can i run it with my air box there? and it still go inside the frame?

 

I have the esr trx5 pipe on my 250r and yes you can run it with the airbox IF you get the standard mount pipe and not the center mount pipe. Its a great pipe and produces more power everywhere.

1986 honda trx250r-esr trx5 chrome pipe and silencer, ac front bumper, ac skid plate, renthal bars, rear douglas rims w/ 400ex tires. On the way-Maxxis razr rear tires

1995 yamaha blaster - many mods - sold

 

Hondaman85:
There are 2 different models of the TRX5: the "regular" TRX5, and the "center-mount" TRX5. The regular TRX5 is routed as all other pipes are. The centermount TRX5 pipe goes inside the frame near the kickstarter, like all other pipes do, but it stays inside the frame (all other pipes come right back outside after they go around the frame at the kickstarter. The silencer on the TRX5 centermount is located INSIDE the frame rail,under the seat. That's the reason way the airbox needs to be removed. The advantages of the centermount (other than it looks cool as 'ell!), are mostly realized by big bore/stroker engines. The shorter pipe stinger aids in scavageing exhaust gasses, allowing the engine to run cooler, and thus build more power. Smaller engines benefit from the TRX5 centermount, too, it's just not quite as noticable.

Hope that clears things up.

-doug

 

Thanks lumpdog, i understand perfectly now.