[rookie Roy]

I recently switched from a completely built 2whl Honda CR250 to an 02-660 Raptor. I added a Race series super trap pipe, Pro taper Bars and clamp, and some other crap, but no motor work. What Id like to do is add a stage 1 cam but am not sure what else I will need to do. Id like to keep the stock boor. Cash is not a big problem, Im more concerned about somthing that is going to run well, and have a little more midrange. Do I need new valves? Springs? etc. Id appriciate any suggestions.

 

[660RaptorR]

With a stage 1 cam you dont need to change the valve springs. Maybe do a port and polish while your @ i
My bike is also in for a engine rebuild: Stage 1 cam, port and polish, 1mm oversize and some other goodies. Will post the results later this week as i should have it back before friday.

 

[Mad Dog]

If the 02 doesn't have too many hours your OEM valves will probably be fine, just make sure the seals are in good shape.

A stage 1 hotcam is pretty much drop in, just make sure you remove the decompression mechanism from the stock cam and put it in the new one.

You don't have to upgrade the piston but IMO it's a great upgrade even at stock bore. I'd suggest an 11:1 wiseco but make sure your cylinder can take another hone at stock bore before ordering it.

 

[rookie Roy]

Why a new piston? You say 11-1 compresion. If the piston diameter is the sam, what is the difference? Is the top of the piston crowned to make greater compresion?

 

[SpDdEmOn]

Yes, exactly.

 

[Mad Dog]

Why a new piston? You say 11-1 compresion. If the piston diameter is the sam, what is the difference? Is the top of the piston crowned to make greater compresion?

More compression makes more power even with the same size. But sometimes the cylinders are too worn out to take a hone and seat a new set of rings or meet the clearance specs of an aftermarket piston.

 

[rookie Roy]

Great info. So right now I have found a local dealer that will do the port and polish for 200 + tax. I can do the cam my self. I found one on a moto site on line for $149.50. I think Ill start with the cam and the port an polish, and depending on the time it takes to get the head done, possibly put in a new piston. I am an authorized wiseco dealer so the parts are pretty cheap for me. What kind of wiseco piston do you guys recomend? With the 2-strokes they usually have several types, like a prolite, stock, etc. ??

 

[Mad Dog]

Wiseco only makes one type for the 660 raptors, and only in one compression from the stock 100mm size to the 102mm which is the largest one can safely bore to using the stock sleeve.

Honestly I think that with a stage 1 cam your 200 bucks is better spent on the piston upgrade than porting.

 

[SpDdEmOn]

Yeah, he is right. I also wouldn't do the porting myself or have the local dealer do it. That it work that needs to be tested with a flowbench and matched to your setup.

 

[pewterpecker]

Check ebay. I would suggest the stage one cam and an 11:1 piston. Those two are going to be your best bang-for-the-buck mods and make a big difference.

I would also suggest hitting up one of the forum sponsors for your head porting if you decide to go that route. The sponsors we have are some of the most knowledgeable in the country with the 660 engine.

 

[668rap]

On ebay you can get a brand new hotcams Stage I or II for the same price right around $135 shipped. I would also recommend the 11:1 piston. I have one in my raptor but it's also bored .020 over and I wouldn't be able to tell you if the compression alone will help. If you do get a stage II cam then you will need new springs. And that's when I would get it ported and polished. I mean you can do it with a stage I you just wont see as much performance as you will when you do it with a stage II.

 

[RFguest163451]

it's also bored .020 over and I wouldn't be able to tell you if the compression alone will help

there might be a .5 hp gain from a .020 over bore, the extra power you feel is from the increase in compression