I know very little about atv's in general, but I can and have the knowledge to turn a wrench, just never worked on bikes or atvs.
I came across an early 250 Mojave that was too cheap to pass up. I have replaced the rear bearings, oil and filter and the stock carb with the 400ex carb.
The original carb was shot and I could get the 400 carb cheap.
It runs faster than I need to go, and other than the carb, it is stock.
Please tell me in simple terminology what I can do to improve performance. I am not an idiot, just never owned or worked on fourwheelers before. I am not sure how to approach it.
It is not something I want to spend a fortune on, but I am curious as to what is feasible. I hate that i didn't get into this when I was younger, because it is the most fun I have had while sober.

 

with that carb bigger carb you'll need to let it breath better since it's gulping more. get a decent exaust/then tune the carb

you could get some holeshot rears to start off with which will help your grip and give you quicker excelleration depending how small of a size you go (i would recomend 19 or 20x10x10 or something close to that)

then there's the sprockets you can mess with, but that gets you into either faster accelleration/top speed.

then there's suspension, handle bars, protection for the under carriage, tons and tons little things out there.



I would honestly just ask yourself two things.

a) what type of riding you will mostly be doing with the jave' so you can update it to those needs
b) how much can you spend? (or how much do you want to spend on a 250 if you don't have a budget)

those are the building blocks of any build up. It's up to you my friend

if you want to give me a response to those questions, I'd be happy to give you my thoughts, and I'm sure everyone else would as well. I posted a topic on "interchangeable mojave/lakota parts" on the main page that has some good info, so you might want to take a look at that to save some money as well.

 

Mostly I'm just speed freakin up and down the street. The back of the yard is terraced, so I have plenty of small jumps to make. The tires are in very good condition, and I probably will run them bald. The sprockets are in need of replacement. I never realized how high exhaust upgrades could be. I can't tell if the 400ex carb has any other adjustment on it other than the idle speed adjustment???? If I decide to bore it out, how much over and what other parts do I need to upgrade. With the parts I have replaced and the cost of the Mo itself, I have less than $200 in it. Most exhausts I have seen are that much or more.

I really don't know what I want, and I don't fully understand what I need to do or where to get parts or information. I am hoping ya'll can point me in the right direction. I want it to be an enjoyable ride, but reliable as well. The engine runs strong, bot I know there is room for improvement. I know the carb is too big and I am open to suggestions on how to improve it.

I need advice and patience. i can work on the car or truck all day long with no trouble, but I know nothing on where to start with this thing. I look forward to tinkering with it, and that is why I have come here asking for help.

Sorry if I ramble on. i raelly look forward to you responses!

 

first off i wouldnt worry bout tires if your riding on the road cuz there just gonna get worn fast...next off if your running the 400ex carb theres a few guys that i know do upgrades like that but id suggest cleaning it out if it came off a bike that was not running or hasnt been run in along time...id also say check your air filter located on the left side of your quad...where that black box is...idk if u relocated it while doin the EX carb swap...but make sure that is nice and clean...id suggest washing it out wit soap and water let it dry good and then get some oil and rub it on it so the dirt and dust sticks to it instead of goin in your motor...your def goin to have to adjust the carb but well get to that afterwards...u said that the sprokets need replacing thats no problem ill give you places u can order them from...but wut alot of people with lakota's and mojaves do is up a tooth on the sprokets...right now your running a 12 tooth front sprocket get a 13 tooth youll notice alot more top end speed also the motor run better because its more of the way they should have been geared from the factory...u may lose some bottom end but when i did mine i notice nothing gone...for the rear just get a stock size til u mod the motor more...there a wicked sproket combo u could do but well wait to talk about that til the motor has some more goodies on it...exhaust system can get pricey like u said...but the only ones i would suggest for mojaves would be Big Gun, supertrapp to if you can find one...but like i said id first start off with a new chain, sprockets, air filter...clean that carb with some carb cleaner as well...maybe runs some like STP carb cleaner too cuz like i said if it hasnt been used in a while just want to clean it out...the 400ex carb has a fuel/air mixture adjustment to which u could play around with it may be running rich or too lean...better i always say to have it running richer...this way u dont hurt the motor...with boring there are a few options 300, 330, 345 or if you want to go all out a 370 stroker but the price ranges adjust alot...ill give you some website to check out for parts and stuff...

Rockymountainatv.com (chain and sprockets id go here for cheaper maybe look into a K&N airfilter or twin air those 2 are the best...
Denniskirk.com ( good for gettin parts to your house fast more $$$ though)
Cycleworksracing.net (great guy to talk to knows everything and anything about lakota's and mojave's...if you want motor work done he's your man...

but check out these site and let me know wut your think for mods and parts your looking at...here to help so dont be shy...
Victor

 

Thank you! This is the info I'm looking for! I will look them over.