250sx Upgrade options

[Larry T Moore]

I wanna do the tire swap but use aluminum wheels..

[dougspcs]

I wanna do the tire swap but use aluminum wheels..

They look cool, but they have their downside..for track and trail they are decent. But for the really rough rocky terrain I like to ride sometimes they take a beating..

[neverdone]

Heck yeah I would try the swinger stretch if I could find the swinger! I don't have a problem with fabbing stuff, I do it all the time! Don't really care for his mondo huge tires on the back though!

[dougspcs]

Heck yeah I would try the swinger stretch if I could find the swinger! I don't have a problem with fabbing stuff, I do it all the time! Don't really care for his mondo huge tires on the back though!

Try the tires 1st and see if you think the extension is still needed..I think you'll be surprised how much improvement you'll get from just that.

[my1423]

Usually the biggest bang for the buck is more displacement.
Never done it myself.
I have read of people putting the trx300 and trx350 quad motors in the sx ex.
Wide rang of years for those motors. late 80s through middle 90s were all the same.
Remember something about swapping the left case and drive shaft assembly off the 250 but other than that a drop in mod.
The 4x4 had another issue with a bigger output shaft or something.
Some were modding things to put in the 400 motors, but that required frame mods due to height differences.

[Larry T Moore]

They look cool, but they have their downside..for track and trail they are decent. But for the really rough rocky terrain I like to ride sometimes they take a beating..

Ive had aluminum wheels before and theyve held up fine everywhere Ive rode...Im not a fan of steel wheels to begin with but I ride in abandoned stone quarries..limestone pits and they suite me fine...the ones on my 86 200x took a pounding and still looked as good as they did when I first got the bike

[dougspcs]

Ive had aluminum wheels before and theyve held up fine everywhere Ive rode...Im not a fan of steel wheels to begin with but I ride in abandoned stone quarries..limestone pits and they suite me fine...the ones on my 86 200x took a pounding and still looked as good as they did when I first got the bike

I often ride in the Canadian Shield..trails with big granite rocks often bigger than footballs..

Don't get me wrong I have a place for alloy rims too..my 350x still has its stock rims.

But for the most severe riding when I'm 20 miles in bush on a rocky trail I want steel on!!

[neverdone]

I will for sure get the new tires first, but if I stumble on a swing arm I am sure I will snag it just to give it a whirl..... I doubt I will ever try and go bigger on the motor though it could be fun but just way to much work. I like to do small changes just to get the most enjoyment out of them...

[dougspcs]

I will for sure get the new tires first, but if I stumble on a swing arm I am sure I will snag it just to give it a whirl..... I doubt I will ever try and go bigger on the motor though it could be fun but just way to much work. I like to do small changes just to get the most enjoyment out of them...

My philosophy also, the engine and trailing arm change ups talked about in other threads just seem to me too much work for too little again.

But then my life is so busy with kids and work I'd rather spend the little bit of time I get on the trails not in the shop.

[6speedthumper]

FST still offers a 310 big bore kit for it. They also offer cams, as does web, and megacycle. I have a web in my 8 trx300fw. It is their bolt in stock spring profile, and coupled with the high comp std bore wiseco it works great. I also have a Supertrapp IDS2 exhaust, hotshots cdi, and EBC DRC kit. It is a very dependable, stout, and fun quad. If I were you, that is the route I would go. Higher comp, maybe bored out .040 or even .080, cam (porting if you intend to use a bigger cam then a "stage one" type), exhuast, cdi, better carb... Very fun, very dependable, simple, and dependable. Carb jetting isn't too bad. You just need to know what each circuit does, how to read a plug, and know what changes need to be made. Not hard.

[neverdone]

I can handle the porting, changing cams, jetting a carb and yes I know how to read a plug, just don't want to do all that work for just a little gain nor do I want to spend a fortune on this old machine. I just like to do some things to make mine stand out from the rest, and I like to try and get some good handling and performance from my efforts

[SawyerCustom]

general rule of thumb when rejetting.. new exhaust, & opened up air box = up 1 main jet size, since half steps are hard to find, if you open up either the 1 jet size up will work, when you change out the carb is when the jetting gets tricky.. Depending on how many MM you go bigger will dictate how many sizes up you need to go.. keep in mind, the primary jet will need to be changed also if you mod the motor too much.. There is not a lot that can be done purchase wise, but also thinnk about milling the head .010, .020 (Up 1 jet) and also porting the head (free HP) polishing is not required because it will just get covered in a few hours of running.. Cleaning out the casting marks and making the ports bigger will help with flow and give a noticable amount of power diff. I do like th front tire swap idea, I have a gnarley front tire on my 250sx so I'm not going skinnier plus it's for sale so I"m not going stupid with it, but I do like the idea and may try that if I get one I actually want to keep.. 22's on the back seem to be the perfect size for speed, mud, and all around performance.

[neverdone]

New shock boots showed up yesterday, decal set on the way. Once the quad is all back together I will start in on getting the trike up to snuff. The wife and I are trying to make a wheeling trip before she goes back to school this fall (teacher) so we will see how it goes.

[Outlaw #24]

I saw this thread and decided to Chime in! I was going to Purchase a SX from FlyingW (Jim) in the spring! It was Called Storm Trooper it was cool and had a 350X front and was just really Cool. I didn't get to purchase as I waited to long and somebody else got it. Well I wanted it for the Wife. Since I missed out on that one I looked for a nice one that I could modify myself , I picked one up from EBay at a pawnshop in Omaha Nebraska and paid what Jim wanted for his ,(Shoot), Told a friend and he said he had a 350X but no Brakes, so I bought that. I found a Brake system on EBay. Get this now! We bought the SX April 19th, completely stock but has a nice Cobra header. Got the Front less brakes the 22nd, Installed the front on the 28th, spoke to the dude with the brakes on 29th and he sent it then from California, (I paid Extra to Expedite), got it May day and installed it. Loaded the Trailer for Trike Rampage, to take off the next morning . The SX looked awesome (like my Wife) worked Way good. FlyingW gave me some pointers and gave me a stirring stop for the new front Because it will SLAM the tank without it, (Thanks Jim) one of the guys from Missouri that was at Rampage, (Thanks Steve)gave us a wheel as ours looked like it had had a taken to it! I recommend listening to these guys! Just Sayin Connie loves The SX She Named it Sexy

[neverdone]

OK, so I got my new tires in and new front wheel!!!

One question for dougspcs......... Since I don't have the front tore apart yet, what direction does the new wheel go (which side is the valve stem on)? That way I don't put my tire on backwards and have to redo it....

I will post some before and after pictures when it is all done and I have it all back together. I think it's transformation start to now has gone pretty well.