Big Bore sx/es

[bigredmatt]

Did anyone ever get to install one of these kits on their 250es/sx? What did it include in the kit and was it hard? Can anyone hook me up with one?

Thanks a Million,

Matt

[250sx]

I'm still looking for the kit myself. Now I'm wondering if it wouldn't be easier to try and swap in a whole trx300 motor. :shrug:

[whiteman350x]

J&M atv supply sells this kit. It is a brand new cyl., head and base gasket, piston and rings, and the dowel pins. It will take you to 300cc's.

[250sx]

got a website or phone number?

[bigredmatt]

www.jmatv.com

I went there but it says they only will sell to dealer....thats pretty stupid. Have you got any idea what they reatail for?

Thanks,

Matt

[whiteman350x]

Don't remember what they sell for. The ph# is 1-800-367-9603. The sell to dealers only. My local parts house was a dealer and the O'Rilley's that I work for is supposed to start being a dealer also. Call J&M and they can prolly tell you where the nearest dealer for their products is. The kit part # is:MB300

[Black Sheep]

hmmm, is it time for a 250SX big bore thread ???

[bigredmatt]

Hey mr atc do you know much abotu these bigbores? How much power do they give you, if any at all?


Thanks,

Matt

[Black Sheep]

Personally, I'm not a fan of hopping up SX's. I personally would just buy a 200X or 350X instead of hopping one (250sx) up.

Profesionally just like a 350X (just not as many options) it all really depends what your trying to acomplish. you can go up to 300cc and still have almost the same reliability.

The big mistake I see people make with Big Bore 4 strokes is to just put a bigger piston in it and leave it at that. What they fail to relize is the cam, carb, porting, & pipe are designed for a stock bore. by not changing these parts to match the piston not as much is really gained with just the piston

To do a Big Bore 4 stroke the right way and get the most out of it is to do everything together as a set. and to do that you need to figure out your budget and what your intended type of riding is. different cam profiles, pipes, and carbs work for different types of riding.


If you really want me to give you accurate advice that would work the best I would need the total amount of money you can spend on parts and labor, (unless you do it yourself you have to pay someone and most shop rates are around 45.-50. and hour) the type of riding you do the most I.E. woods, tracks, dunes, and if you can and want to buy race gas.

[bigredmatt]

Im not sure what i want to do MR ATC. I really want to get my 250es up and running first before i do touch the engine. I am much more focused on the restoring part for now. I knwo the 250es isnt a performance machine but it woudl be nice just to have that little bit more grunt when haulign a load or dragging a log etc etc. I might wait a few months and wait till shes running then ask the same question again......Im really undecided.

Thanks Alot,

Matt

[BIG BAD RED]

right now im looking into trying out the xr head...pre 84....or the trx250x topend might be a easyer swap...the reason for this would be...more cam options....4 valve set up oposed to 2...a better flowing stock port setup...a 2 into one exuast...and the posibility of a 11:1 or a 12:1 ratio....but reliability is still my main concern...

[bigredmatt]

Yeh id like the old girl to still be reasonably reliable too. One of the main factors. Do you think the old xr250 head will bolt upto it though Cody? How would i be able to run 2 pipes into one. Wouldent the frame interfere?

Matt

[BIG BAD RED]

thats why i need the bike up here....i can make up a exuast for it...make a few for it at that rate but i still need to find out the best path to take...i think using the xr head will work but i still need to mesure everythign and work out some formula's with it all...i cant wait

[250sx]

I'm not looking to race Tecates. I just want a little more power without having to run race gas. Premium is fine though.

[BIG BAD RED]

for that dan i think your best bet would be to make a better flowing engine...from airfilter to muffler...and everythign in between....a carb would be a must if your increasing your airflow...

[BRR]

"I knwo the 250es isnt a performance machine but it woudl be nice just to have that little bit more grunt when haulign a load or dragging a log"

many people don't realise it but a 250es is not limited to doing work, they have plenty of power for playing and i would look forward into buying one of those kits for mine. i take mine trail riding and mud boging all the time. work is best left to new 4x4's.

[conig]

I am interested in a big bore kit.

the big red may not be a performance machine but I am determined to make mine "sporty". as in something I can trail ride.

[BIG BAD RED]

it is perfect for trail riding...but we jsut want to crunch out big oputput numbers and to have a atc of today wiht the large capacity engine and power