I have kind of a project quad that I'm doing. My question is...What would make more usable hp...a 250X bored/stroked to a 352, or a 350x..Can anyone give me a HP estimate on these 2??

250x has 5 gears and the 350x has 6 it will cost around $800 to put a 6th gear into the 250x motor go with the 350x motor you can still run regular gas. the 352 motor will probably need VP race fuel that is $7-8 a gallon

Would a 350x head fit on a 300ex?? Would that bump up the displacement to 350? I would still like to have reverse and topend isn't that big of a concern. I want more power(displacement).

the 350x has a different cam so it will not fit on a 300ex only other option is the 365 kit or the kit i have from TC racing the 405ex
but do you really want to buy VP fuel all the time

hey exotic1 where in the heck do you buy your racing gas? come on over and i`ll sell you turbo blue 116 octane all day long for 5.00 a gallon.of course i will be buying for 4.00 a gallon. check around if there are any race ,<car>tracks near you guys.we have several around the tri-state area P.A M.D & W.V.....thats where youll get the best prices also check out any gas stations near race tracks

i buy VP fuel which is VP114 this is what the motor was designed to burn its around 34-39 dollars a 5 gallon drum its a race bike i really dont use it as a daily trail rider

Ok, I would like to know how you get a 300EX to 405 and a 250X to 352? My local dealership said that as big as you can go on a 300EX is a 305big-bore kit, cause it can only be bored 60over. So how are you getting the extra 100CC's? Also, can the 405 still be raced in the same class as a 400EX like the 250 2-stroke class? Thanks
Oh yeah, and which makes more HP, the 400EX or 405 bored 300EX?

Does anyone know who sells a 300-305 kit for the 300EX. I would like it to be at least a real 300 if I can't put a 350 topend on it. How much more horsepower does it put out? Does it run on pump gas? And most importantly how much would it cost?

do you have to run race gas in a 300ex with a 330 kit??

Tc racing did my motor the cost was around $2600 for the motor work carb and supertrap pipe with 4"head pipe. They take out the stock cylinder and cut the head to accept a bigger cylinder. Then it is pressed in to place. I bought this bike off of a racer that raced was a class B rider who rode in the 4 stroke 400cc races with the yz400s and races against Sue Parker.