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what now?
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Posted by: '2400ex

I have a question? I have done the exaust, K and N jet kit w/air filter. Done clutch upgrade and holeshot tires. What should be next in performance upgrades. I dont get to top end. I was thinking a 440 big bore kit with a stage 1 hotcam.But what else. Need pro and cons.

Posted by: TRXNIGHTRIDER

u should also think about getting an aftermarket rev box, itll make a big difference.

Posted by: '2400ex

What is a good one and where can i pick one up at a good price?

Posted by: johnsls

Ebay or check the 4sale section and do a search..

Question - With the mods he has or even what I have and we rejetted.. Would you need to reject bigger or smaller with the new air box??? again?

Posted by: CHEVYZ

Get you a good cam and a decent rev box. For a cam, I would recommend getting a HRC cam, but there are plenty that work well. Most rev boxes will work decently. Make sure the one you choose does not ONLY increase the rev limit. Look for boxes that advance the timing and do more than just raise the RPM limit. Since you say you don't see the top-end, go a tooth smaller on the front sprocket. You will lose a small amount of top speed, but there should be a noticable increase in acceleration. Aside from that, the rev box and other mods should nearly make up the top speed that was lost. Take the choke out of the stock carb or get a new carb... for the price, I highly recommend a 450r carb.

To hold up with a 440 you will want to change more than you should if you don't really need it. If you are gonna change the bore size, go with a 416 or a slight overbore. I wouldn't recommed changing the bore... big bores can be a PIA. If you do feel the need, don't go much. Like I said, though, it isn't necessary.

Posted by: '2400ex

i dont get how a rev box helps in power. does it just incrase the rpm before you hit the limmiter.

Posted by: CHEVYZ

Most rev boxes do more than give you more RPM. More RPM alone is usually pretty much useless since the power up top will just go to waste on a moderately stock engine. What you are looking for is boxes that do more- advance the ignition curve, give hotter spark, etc. Now, once you do more to open it up... changin the cam and other componets of the type, I could see where a rev box would make a noticable difference. I noticed the difference on my 05 450r when I put a rev box on after installing a cam. It seemed like it livened it up a little more. Guess that is my view on it....

Posted by: '2400ex

well that explains a lot, thanks. What can i do to get a higger compresion. That is what makes to power to. And can you run a 11 to 1 on pump gas?

Posted by: CHEVYZ

The best way to raise your compression would be to just change out the stock piston for an aftermarket one. Personally, I would go with JE, but Wiseco is fine as well. JE is a little more accurate with their numbers. Most aftermarket pistons are usually lighter than stock as well, so that is a plus as well. 11:1 is usually safe to run on pump, but it depends on where you ride and all engine take it a little differently. Running a 50/50 mix is usually the best idea just to be safe.... air cooled engines. However, I don't think that changing he piston for higher compression really gives as much of an increase as other mods. I would try to see that if nothing else you get the other componets first.

Posted by: '2400ex

i just wish i could afford to get a 405r
make that a 450r

Posted by: '2400ex

but i ride in cooler temp up here in ny