2012 CRF500F---whoa, what?!

[txkawboy]

478cc CRF/CRE with a fabulous 18" rear...

Curious, anyone know if this is merely a punched-out CRF450, or what?

What about the 2012 CRe125 2T ?

Heck, I did not even know that Honda-Montesa was "building" anything but the usual trials/dual-p stuff...maybe this is a 'testing ground" for American Honda, anyone know?

http://www.hmmoto.it/ita/scheda.asp?idFam=1&idProd=235

[Shawn_Mc]

For whatever reason its got a bigger bore. The standard CRF450R engine has a 96mm piston, that one is a 99m.

Its that Italian?

[JJRace]

www.servicehonda.com

2012 CR125 CR250 CR500 2 strokes

[Shawn_Mc]

www.servicehonda.com

2012 CR125 CR250 CR500 2 strokes

The bike up there that TXkawboy is talking about is a thumper.

[Desert450]

too bad we cant get a bike like that over here. ?

[Qqqqqqqqqqqq]

here , build your own .

i prefer the standard bore

http://www.ebay.com/itm/05-09-CRF450X-CRF450-Cylinder-Works-Big-Bore-Kit-3mm-/190512257564?hash=item2c5b6a5a1c&item=190512257564&pt=Motorcycles_Parts_Accessories&vxp=mtr

[Ron Hamp]

im building a crf 517 from a 2009 crf fuel injected bike the crank is being done with a longer rod to keep the rod ratio .

[fastforward55]

517 CRF How much HP and torque would that make? Would it still be dependable? Most big bores are lower compression why is that? I am new to four strokes and a lot to learn.

[Shawn_Mc]

im building a crf 517 from a 2009 crf fuel injected bike the crank is being done with a longer rod to keep the rod ratio .

The longer rod would suit flat track and road race apps too with the stock bore and strokes.

Who is doing the rod?

[Ron Hamp]

the rod is a carrilo from a i beleive a klx 450 the crank pin is also 1 mm larger im using a front chain guide from an 08 crf and building a spacer for the cylinder were using a clylinder works kit on top of it.the crank cases are going to need a little clearancing in the centers for the rod the connecting rod is also being machined crank works is doing the crank mods .with the new cams i have and good fuel i expect to see around 70 hp i had 490 carbed engines @ 68 hp pretty eazly a few years back the older trx motor was eazy to make big i had one to 570 ccs.

[fastforward55]

Will the 517 cc be High Compression? Or like most big bore kits around 12.5-1.

[bushman45]

maybe a ktm rod about .090 longer?

[Ron Hamp]

the rod is a carrilo for a kawaski and is 5 mm longer.

[Jon-D]

Increasing the rod length is good for hp but it does seem to affect the handling. I have had a few BB kits installed and rode several BB kit bikes (some experimental) and the common trait between them is they felt "heavy". This can be a good thing if you are riding off road and do a lot of high-speed stuff, but turning can be a little more work. This characteristic is obviously a disadvantage on the motocross track.

I recently had one of my bikes punched out to a 490, which was almost the biggest I could go without increasing rod length. i could have increased it to 500cc but would have use an iron cylinder. I kept it at 490 rather than bumping it up to 500 because i wanted similar metals between the piston and cylinder so when I ride it in demanding conditions the expansion rate between them would be about the same and minimize the chance of seizing it. The bike still handles like a motocrosser, but with extra hp, which was my goal.

What I like about the four stroke motors is you can really personalize them to how you ride and the conditions you ride in. There are so many variables and things you can do to them its just like ordering off of a menu. Along those lines the heavy feeling I mentioned before on some of the BB kits I rode can be mitigated with extensive work. But it almost becomes cost prohibitive for the recreational user at that point.

[Ron Hamp]

the customer wasnt concerned with cost and its going in a quad i sugested a smaller engine package and he wanted the bigest baddest engine he could get.

[crf-500]

i never regreted kikcing out my 450 motor in favor of a 2 stroke 500 and its really not that mutch work it depends a lot whitch bike you start with

[ah665]

That original site has a 2012 crf300r. I would love to have that.

[Jon-D]

That original site has a 2012 crf300r. I would love to have that.

why not take your current bike that is allready set up to your liking and add in a BB kit?

[fastforward55]

How would a 2 stroke 500 compare to 4 stroke 500cc? In a aluminum framed bike.

[Ron Hamp]

the 500 cc 4 stroke would be eazyer to ride and will make more hp over a longer curve provided the 500 cc 2 stroke is left stock .years ago i built a 10000 rpm cr 500 with 90 hp it required an ignition with no rev limiter i machined the cases and welded them and then built a billet cover so that it would except a moto plat ignition we had a krober tack on it i weldedup the reed area and installed a kx roo reed asembly it had a bored 44 mm mickuni and a custom built pipe it was in a quad chassis you could barley get it out of secound and 3rd gear before the tach hit 10000 rpm.