250 Big Red Cam

[3wheelsoffury]

im wondering if a cam out of a 300 fourtrax would work in my 85 250 big red. Has anyone done this and if so, how good did it work?

[Pearl_Diesel]

the 250 B/R and TRX250 fourtrax utility both completely interchange, as well as some of the top end of the 300 fourtrax utilities. I infact swapped a big red engine into my fourtrax. The cams are the same, but supposedly the B/R has a better cam out of all of them, a more performance oriented. I haven't seen this to prove it, but on other forums the 300 guys swap ATC cams into their rides. I think, not sure, but the ATC 250SX is supposed to have a more performance oriented grind. The 250 and 300 utility fourtraxes are less so. Otherwise, if performance is what you want, Google Web Cams and they have a few cams for the 250's. A little pricey, but sometimes you get what you pay for.

[torque]

just checked on webcamshafts they still make a performance cam.

http://www.webcamshafts.com/index_bl...le_search.html

[3wheelsoffury]

thankz guys, much appreciated. im waiting to get more power to turn 27" Laws so im probaly gonna do a cam

[3wheelsoffury]

i ment wanting

[Pearl_Diesel]

What i've always wanted to do, since apparently nobody makes a big bore kit, is to get a big bore kit for a 300 utility (jugs are the same, again, supposedly), get a custom high comp piston (apparently 250 and 300 have different sized wrist pins so they don't interchange) get a web cam, valve springs, clutch kit, serious carb jetting, and run a harley chrome muffler. ) cuz it looks cool. lol Besides that though, I've got a recon and it'll turn 25's pretty easy, and it's got half the balls of my fourtrax. Otherwise, i've been thinking of having the cylinder head or jug milled so many thousandths to boost compression and just getting the right jetting and exhaust setup. Removed the factory airbox and just relocated the filter and battery inside the toolbox, and used a Spectre filter from autozone for some serious flow.

[3wheelsoffury]

sounds sweet. it turns them laws i got but not like i want it to. so cam is prob gonna be my best bet

[Pearl_Diesel]

Throw that in with the proper jetting and good exhaust and intake and it would probably work good. Next step would be a good clutch kit and some springs. Relatively cheap on ebay.

[3wheelsoffury]

was just looking at the clutch kit, thanks

[Pearl_Diesel]

I don't know if you've found this out or not, but I've been constantly looking for upgrades to my old 250 that seems to be so hard to find speed parts for, and have found that 4 stroke tech makes big bore kits and cams as well. It's run by a member of this forum. He has a website, but those particular kits aren't listed, you have to call. He said on the phone that the prices are the same price, and essentially the same kit as those for the 300 fourtraxes. He sells two, a 78 mm piston, and an 84 mm one. (stock is 74!) and says to send in your cam for grinding along with it. Prices aren't terrible either.
Just trying to help you what I can, it's taken hours of websurfing to find this all out, and I'm just trying to pass it onto someone else that could use it.

[3wheelsoffury]

thanks man, not really looking for speed, more low end to turn 27in outlaws. It turns em but not like i want

[torque]

I don't know if you've found this out or not, but I've been constantly looking for upgrades to my old 250 that seems to be so hard to find speed parts for, and have found that 4 stroke tech makes big bore kits and cams as well. It's run by a member of this forum. He has a website, but those particular kits aren't listed, you have to call. He said on the phone that the prices are the same price, and essentially the same kit as those for the 300 fourtraxes. He sells two, a 78 mm piston, and an 84 mm one. (stock is 74!) and says to send in your cam for grinding along with it. Prices aren't terrible either.
Just trying to help you what I can, it's taken hours of websurfing to find this all out, and I'm just trying to pass it onto someone else that could use it.

replace speed with low end power for turning 27's . i think thats what pear diesel was talking about, at least that is how i took it

[3wheelsoffury]

o ok. misunderstood

[TheRealFatShady]

You can also look into a gear reduction, but that requires some custom machining.

[3wheelsoffury]

how diffacult would that be?