Pipe Or Big Bore Kit??

i got a 07 yz250f and about 1500 bucks to put towards my bike. its stock now. Should i go with a big bore kit or pipe first? or any other mods yall might recommend??

If you have 1500 you could get a pipe, cams, and a high compression piston. I think that would be better cuz the big bore motor would probably not run really good with the stock stuff.

is there anything extra i have to get if i get a high comp piston? like valve springs or anything like that? and if i go with the big bore kit, anything special i need to do to my bike or is it just buy it and bolt it right on a stock bike and everything will be ok and not break?? and the hot cams, anything needed for those?

Heres what im wanting so far:

290 big bore kit or just a high comp piston

intake and exhaust hot cams

rear spring (correct rate)

fork springs

pro circuit ti 4 slip on (unless someone can recommend a better one)

JD jet kit

If i where to get all this is there anything i need to do to anything else on my bike? Need help quick cash is burning a hole in my pocket THANKS

Get your suspension revalved, get a big bore kit because it'll give you more performance then any pipe or high comp piston. I use to run a high comp piston and my big bore kit gave me more power then it would.

so changing the springs on my suspension wont be enough for the suspension aspect?

Here is what I would do..... 262 kit with a 3mm stroked crank (can you do the work yourself or know someone that can?) hot cams and HC piston. if you can do the labor yourself you can do all this for approx $900(look for deals). Make sure you have the right springs for your weight and spend some time on the bike and properly adjust your suspension (these bikes have some of the best suspension ever). Now dump a quite pipe on it so everyone can hear you giggling from all the fun you are having with your new found power and killer motor...

If you don't care about maintaining your stock displacement, get the 298 Vertex big bore kit, and a suspension revalve from someone good like Factory Connection, MCR, or a good local place other people recommend. I pipe will help the motor breath, but a pipe alone won't give you the power of a big bore kit.

I suppose it also depends on what kind of riding you do. If you like to scream the RPM's and hold it WFO all the time, you would be better off with a stage 2 cam, pipe, and port work. If you want torque and mid-range power, get the big bore. A stage 2 cam will also help balance the power band so you can still wind it up in the RPM range to some degree.

like the last guy said if your a rever go with hot cams stage 2. but if you like low end grunt go with a 290 kit. they are torque monsters after a big bore kit is on. have your suspension revalved and re sprung for your weight.

290 Kit from Luke's Racing $500

FMF 4.1 Slip on $350

GYTR flywheel weight to smooth out the power delivery GYT-5XC97-50-50 $105

Thats $950 for motor parts

Enzo suspension

$250 + for front revalve/rebuild

$205 + for rear revalve/rebuild

Bam, every penny spent.

How much of an increase do you want and where do you want it? A little, a lot, low, mid, top end, everywhere?

Re valve suspension and get a big bore.

best value you can get for improving the handling of your bike period.

and if you want a better flowing exhaust id say keep an eye out on ebay for either a cheap or used slip on. and just spend 35 bucks repacking it.

if you get the 290 kit the bore will be to big for the stroke. i read all about these big bore kits and if you plan on not geeting the motor stroked as well as big bore, the go with a 262, it is the best for the money....

annd remember suspension is everything!

i wouldnt say that.. theres hundreds of people who would say otherwise.

the athena makes LOTS of powerful and is very reliable if your engine head isnt beat to a pulp. it doesnt lose some of its 250f characteristics though.. (the bike will make more power lower in the rpm range)

Heres what ive got up for order

Athena 290 BB kit

new front and rea springs

hot cams intake and exhaust

hot cams shim kits

jd jet kit

yaoshi rs2 comp slip on

Any body got any thoughts or ideas on how to improve this combo???

Get in shape so you can hang on!

haha i hear ya but pipe n everything sound like a good combo?

wow yeah second on that your bikes gonna have so much power you wont know what to do with it with that combo.. id say hit the gym!

now did you get stage one or two hotcams?

that things gonna be a tractor if you got stage ones :smirk:

Great combo tho, that new exhaust should scream with the 290 kit.

id get new valve springs and seals ext. to make sure the head is up to par to handle that power. Your crank and everything else should be able to handle the power but Hod-rods makes a heavy duty crank you could look into.

oh and one more thing.. is that JD jet kit for the 290 kit of for a regular 250 bored bike? because you will need to go down a few numbers in the main with the bigger bore. ( the bigger bore creates a stronger vacuum pulling more fuel in requiring a smaller jet )

well i havent ordered anything yet just trying to see what everyone says about the best combo to get, but its the stage 1 cams.

Is it hard installing the bb kit?? and cams?

and my price range went from 1500 to 2000 so any other suggestions of what to get would be great.

How much does valve springs and all that usually run?

and the jd kit is for the 250f i think, didnt know they had a 290 kit. and whats the difference? and will the stock jd kit have what i need to jet for the bb kit?

okay one thing about the cams, i would get stage two if you ride motocross and if you ride woods ext. id say stick with the stage ones.

The 290 displacement will make your bike lose a little top end and the stage twos will bring that back.

The athena 290 kit is very easy to install if you have decent skills working with tools and know how to read instructions, its just like installing a regular top end.

Don't get a JD jet kit because it wont be right for the bigger bore you will have to buy the JD needle only and then get the jet's separately from your local shop.

as for all the valve springs ext. its probably not necessary but if you have a decent amount of hours on your bike it wouldnt be a bad deal you can get all these parts from your dealer ( there OEM yamaha parts ) or buy these off ebay->>> i was looking for some for my own bike the other day and came across this deal. ( keep in mind working with the valves can get a little more complicated. )


i would say get these things from your list

Athena 290 BB kit

hot cams shim kits

jd jet kit

yaoshi rs2 comp slip on

save the money from the cames and send your suspension to factory connection, it should run you around 5-600 depending on the work needed.

There amazing down there.. you wont believe the difference it will make if you send your suspension out to these guys.

by far the best money you can spend is on suspension so i would save the cams for later, you can easily install these after you put the BB kit with no problems.

those guys at factory connection would replace the springs and everything including revalving and all that for my weight?? I appreciate all the advise

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