what modifications would you do?

[85 250sx]

ok i have a stock 86 250r atc and ive always been the fastest of my buddies since they only have 400ex's a z400 and a 350 raptor well ive always like that fealing of haha im faster (anyone els or is it just me lol) but one of my friends traded in his 400ex for a trx450 and im getting blown away.

my trike is stock exept for a k&n air filter. what modifications do you think would get me up to par with a 450r i didnt realy want to spend more than a thousand but maybe willing to if i have to what would you guys install or do if you were in my situation thanks

[Dammit!]

An agressive port job, a nice high rev pipe (Paul Turner or something similar), either a rad valve or v-force reed and a 38 or 39mm carb. Get it jetted up right, maybe go up a tooth on the front sprocket and down a couple on the rear. Don't overlook the tires. More power won't help if you're not hooking up. Beefing up the clutch isn't a bad idea either.

[Wickedfinger]

You should be able to take him with just a good pipe and proper jetting - I would start there. In theory you both have about the same horsepower at 39 and you are about 50lbs +/- lighter in rolling mass, so I would have to say maybe you might wan't to consider a top end job too.

[Dammit!]

You should be able to take him with just a good pipe and proper jetting - I would start there. In theory you both have about the same horsepower at 39 and you are about 50lbs +/- lighter, so I would have to say maybe you might wan't to consider a top end job too.

That might work if he just wants to beat him. I was thinking humiliation. :TrikesOwn

[85 250sx]

yeah humiliation sounds gooood

[deathman53]

If you want humiliation, I have a esr330 kit up for grabs $500, you need to have a long rod 87-89 rod to use it, but with that you should do a carb, reeds, pipe. In the more pracitcal sence you should get yor shock rebuilt for your weight and riding, +4 axle, 20" racing tires(holeshot xcr's,kenda knarlys, etc), get a pipe(esr or paul turner) and rejet the carb. Also might be a good idea to rebuild the forks. I always go for handling over power, then work on power.

[Wickedfinger]

That might work if he just wants to beat him. I was thinking humiliation.
lof'nl .......... I would say so then.

[85 250sx]

what conditon is the esr330 kit in? and do you have any pictures? thanks

[hrc85250r]

dude, you can totally beat him if yur top-end is in good shape, just bore it w/ a new piston and rings and a 38mm carb w/o the airbox cover so it can breathe rather than choke and he is toast easily.....gauranteed...i have "smoked" the 450r's, banshees and raptors stock...the only one that keeps up w/ me is the yfz450(pretty hard to tell which is faster), and i am talking wide open top speed down a straight back road.....just my exp.

[1984kxtTECATE]

Im suprised your not beating him stock vs stock, I would go down a couple teeth in the rear sprocket and mabye 22" tall tires. Power wise, airbox eliminator kit, V-force reeds, and porting. You will spank it then.

[Dammit!]

Boring it out when it doesn't need it is a waste of sleeve and won't net any appreciable performance gain.

I have also yet to find an airbox eliminator kit that was worth a **** for a 250R. Tried Trinity's and ESR's and neither fit well without cutting off one of the airbox mounts on the frame and even then the fit would be less than ideal. Best solution I've found so far is to simply get a Uni and bolt it directly to the carb. Or just run with no airbox lid. There's no difference in performance between running a filter right off the carb and simply not using the lid.

Increasing the flow into the engine without increasing the capacity for flow out of the engine (pipe) is kind of a waste of time as well (in my opinion at least). You'll get a more noticable improvement from a simple pipe upgrade (assuming it's one of the good ones) than from a bigger carb with a stock pipe. It's all about flow after all. K&N or Uni filter = more air flow potential into the engine, bigger carb = more air and fuel potential into the engine, reed valve upgrade = same deal, porting = more total flow potential in and out and finally the pipe has to be able to handle the total increase of the previously mentioned mods (and don't forget there are different pipes for different applications with 2-strokes). They all go hand in hand but if you're the one at a time type, pipe and filter is the place to start. I'd follow that with the bigger carb and reeds. Then porting to really bring it all together.

DO NOT FORGET TO RE-JET!!!

Just my 2 cents and some pocket lint. ;)

[deathman53]

its in good shape, about 20 hours on the bore, new gaskets, rings, o-rings, and spacer plate included, I'm including the used piston, you might want to buy a new one, you will need long cylinder studs and a long rod motor(87-89 rod), its been bored once.

[deathman53]

heres a pic of the cylinder when it was on my bike

http://pictureposter.allbrand.nu/pictures/deathman53/330r+8-15.JPG.html

[max]

i always thought longrod was 88 -89. am i wrong. anybody know. i have an 87 motor which the guy says its a long rod but from what i here long rod was 88-89. cool
max

[85 250sx]

Hey deathman is this the rod you were talking about?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=43977&item=4535231718&rd=1

and how much of a hurry are you in to sell it? because if your not in to much of a hurry i might go ahead and buy the rod now and buy the kit from you a little later send me an email at marquez@superpa.net on what you think Thanks

[deathman53]

mine has a hot rod 88/89 crank, thats the long rod(5mm longer). I'm in no rush to sell it, I've had it for 6 months sitting on the shelf.

[85 250sx]

where could i get the long cylinder studs and a long rod motor(87-89 rod),? or where do they sell these kits brand new? thanks

[deathman53]

Nacs racing, Esr

[85 250sx]

do they have a web sight?

[HaggLE]

Hey deathman is this the rod you were talking about?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=43977&item=4535231718&rd=1

and how much of a hurry are you in to sell it? because if your not in to much of a hurry i might go ahead and buy the rod now and buy the kit from you a little later send me an email at marquez@superpa.net on what you think Thanks

That guy selling the rod on ebay doesnt know what he is talking about. He reckons running that rod will increase your stroke. For those that are of the same belief, ITS WRONG! The rod length has no affect on the stroke length.

Sorry guys, these guys really annoy me but now ive vented and im ready to go back to talking about how this 250r is going to kick ass!!!!

[Rex Karz]

The longer rod causes the piston to dwell longer at TDC, and slows down the piston speed for given RPM. I.E. higher rpm's are available.

[RideRed250R]

yes thats wat he is talkin about, honda in the later days of the trx250Rs life decided to make it better by makin more torque out of the motor by lenghtin the stroke but boring it smaller this gave them great bottom to top power but slowed the revs this was better for the MX style the quad was designed for it allowed better low end for corners and midrange for hittin jumps. the 85-86 250R motors are short stroke motors they call them and rev fast and high being able to hit 9k or higher. many 87-89 250R owners take and slide in 85-86 cylinders to increase the size of the motor i have heard claims up to 260cc in size witht his setup. The long rod with the 330R ESr kit will make your atc250R almost untouchable and yfz's will be crying for mercy, if you go over to planetsand.com they will talk very highly of 310s or 330s. i say since you have a short rod motor lets go with this. if you just want bolt on horses do this. many 250Rs with short rods are very top-endish motors because they dont creat the max torque till later int he band and dont fully "explode" there power till later int he band, i would do this cool head, v-force delta 2 reed valve, pt high rev pipe and a 36Pwk carb. that right there should set you back infront of the trx450R by a ways close to 3 quad lenghts i would say, the cool head would giv you higher compression with a 20cc dome and would denftly help out and would run off pump gas, the pipe with its name excluded accutually gives great mid to top power and is highly creditable, the v-force reed valves are also a highly creditable part there are now delta 2s and 3s main difference in reed thickness the 3s show less horsepower but greater reliablity 2s are a bit thinner and unleash full poteintial few rumors say the 2s break and cause engine damage, i have talked to several engine builders, trintiy racing,wicked motorsports, Q and E performance, and have been told the 2s are fine unless ** turnin more then 12K rpms, trintiy racing runs all there drag bikes with the delta twos and even on the cheetah motors that easily turn 12K and never have a problem with the 2s but have tried the 3s and seen a 2 horse DIFFERENCE throughout the powerband. so i would use a v-force reed cage with the 2's, the 36PWk is for the extra top end power. The higher compression, free flowing exhaust and better reeds are all good things to look at with going bigger carb. that set up will be a nice set-up for light low end- heavy mid and arm rippin top end
if * want to go into the engine this is my stage 2: upper rpm port polish, cool-head with 20cc dome, bore and hone to next reasonable size for max power, 38pwk(your really going to be rippin know with a P/P) v-force valve with delta 2's, Pt high rev pipe and ** going to totally destroy the trx450R and beat yfz's in a good race. I would defently look into extending your swinger if you go stage 2. stage 3 is stage 2 with a esr 310 bolt on with trx 9 port and polish. i would go 2 and see wat happens 3 your defently going to need extended swinger and super glue (for your gloves) cause its going to be extremely fast.
good luck
adam

[85 250sx]

is there a big diff in power between the 310 330 350 and 380 and can you run pump gas with all of them and how much machine work has to be done to the bottom halve to accept the 330 and higher engines?

[RideRed250R]

310 and 330 from wat i have been told have totally different potential i here the 330 is a frikin super glue ** hands to ** handle bars and get ready to fly! the 330 requires a long rod bottom end and there is a bolt on 330 kit, the 350 and 380 both require bottom end case boring to fit the sleeves, the 350 is most reliable out of the two but slows ** revs down ALOT * do make impressive numbers but a warmed over 330 might beat * in 300 ft. 380 is full on drag bike with 5mm stroke needing machining to the cases boring to accept the sleeve and it will NOT run on pump gas from wat i hear they are full on drag bikes and arent vary reliable just a drag bike not a relaible duner.
adam

[deathman53]

the bores stayed the same, the rod got 5mm bigger and the location of the wrist pin moved up 5mm, the stroke is the same as well as the stroke. honda did this as the piston life was increased and the reason why 86 pistons are used and 5mm cylinder plates is becuase the crank case volume is increased making more low end power as where the short rods are very top end happy. Also the reason so the spacer plates is so when there cylinders got past the 80 over they could use a 86 piston and go to 120 over(4 more bores), then they would resleave them.

[deathman53]

the 310 is more of a mx motor as it revs alot faster than a 330, the 330 is more of a sand and low end type of motor. the 330 makes unbelieveable torque(and revs slow), the 265 makes good top end and revs fast, the 310(really a 295) is a compromise of the two, good top end and good torque while still reving somewhat fast. With a cr igniton, a stock type bore cylinder revs extremely fast, but makes little torque.

[RideRed250R]

alright thanks, i new they used the short rod pistons for somehting like that i also thought the rods were lengthened for more torque out of them wasnt that also a by product
adam

[mcarp82]

Does anyone know where i can find info on the proper jetting for a 85 250r with a 310 big bore kit?

thanks

[250tecates]

So tell me if I have a 85 lower end do I just need to put 87-89 crank and a long rod to be able to put on 330 kit somebody help me with this if so does anyone have crank let me know thanks

[RideRed250R]

i believe its only the rod that needs to be swapped in .
adam

[85 250sx]

does the 330 kits also need machine work done to the cases because i was looking at the esr web sight http://www.esr250.com/cylinder_kits.htm#esrbolton and the 330 kit is listed under both the bolt on and some machining sections?

how much better is one pipe than the other? with ESr, paul turner, PT, or fmf fatty

[deathman53]

the regular requires machine work and you can use a short rod with it also you have 6 or something bores availble from it too, the bolt on you have 2 bores on it, before a resleave, the bolt-on requires a long rod crank. as far as pipes, fmf sucks, falls flat on mid to top, I love the esr pipe, I liked the paul tuner I had on my trx250r. To get the most from a big bore(330 and up) you need the correct pipe.

[85 250sx]

hey deathman witch is the kit you have and how many bores are left on it?