300ex build

[Green77]

I have just aquired a 300ex project and was looking for some advice on a motor build. Not a race motor just a good build for woods riding, playing and would like it to still be reliable. anyone have a good setup that they would be willing to share? not wanting to wrap up a ton of $$ because it's not my pimary bike. it is still stock bore with a cobra exhaust and uni filter. Any suggestions would be appreciated.

[hardkoratvmxr]

get rid of the cobra exhaust and get something like HMF. will be a better improvement. uni air filter is a good choice so keep that. since its not something that is goin to be raced i would go something like .060" over and something mild like 11:1 compression. you will just have to run 93 octane but other than that it should be a pretty mild and nice running motor. you can get a cam if you want but then you have to keep in mind the condition of the valves and will more than likely have to get heavy duty valve springs to compensate. so imo i would just do the piston and different exhaust and it will be a good little trail rig. and with doing just .060" you have one more bore to go with out going to a "big bore" kit. and if it is just mild trail riding the .060 should last you quite a long time if regular maintenance is kept up with

[MTDman11]

for a pipe get a hmf silencer and a white bros e-series head pipe. ausome combo

[hardkoratvmxr]

hmf now makes a full system for the 300 so there is no need for the wb header

[MTDman11]

i know. i always just heard it was a good set up based on how they matched.

[hardkoratvmxr]

it was an awesome setup but the reason people did it was because HMF at the time did not offer a full system and white brothers (now owned by vance and hines) offered a header pipe that did not require a full system purchase to get

[Green77]

I haven't built anything for a while........would you guys suggest going with a wiseco piston or is there something different out there now? also what's a good mild cam to run? I had already checked out the hmf setup and really liked it, i figured the cobra was doing nothing other than making noise. so .060 over, mild cam, head work, jetting, and hmf setup will be a good reliable ride? or should i leave the cam and head work for later if i want more? thanks for all the info

hey hardkoratvmxr.......i saw your located in evansville, thats funny, i'm 15 miles north of you. any suggestions on where to get the machine work done in the area?
thanks

[hardkoratvmxr]

yea just get a weisco piston. if it is just a trail machine i would not get any headwork done and you shouldnt get a cam. a cam will add about 300 bones to your bill or more since you have to get heavy duty valve springs and stuff like that as well. i would definately get rid of the cobra for the HMF system. i have no clue where to get the stuff done at but any machine shop should be able to bore the cylinder out for you. they will just need your new piston. i havent been home in a year but will be moving back to evansville this friday. where exactly are you from?

[Green77]

sounds good. fort branch

[hardkoratvmxr]

no way lol. before the subway was there right on the highway i used to mow that empty lot lol. but yea if you need anything ill be starting a shop up and can do just about anything so just let me know

[Green77]

small world... Send me a pm when you get a shop rolling, I'm sure I'll be needing goods