Stroker kits bore kits for 250

[rev-man]

does any one know any more big bore/stoker kits for 250ex besides POWROLL

[ryanh250ex]

In short, no.

Honda makes cast pistons designed as replacements in bores up to .040 (making your 229cc 250 a 240cc, approximately).

JE makes a piston that is .020 over, but it is a very high compression (I believe it is 11.5 to 1...dont quote me on that). You'd need race gas to run it.

Someone some time ago told me Thumper Racing made a kit , but it was not advertised on their website, and I never contacted them to verify if such a kit existed.

A few things to note about the Powroll kit...it is also a higher compression piston, and may need race gas to avoid detonation. also, because it is a .080 over piston, if you ever need to rebuild it, you would have to replace the cylinder sleeve because it would be too thin to bore out again.

There are cheaper/easier ways to extract this kind of power out of a 250 than tearing it down and shoving a bigger piston in it.

11:1 and up you need to run race gas. whats the stock compression ratio for a 250?

[ryanh250ex]

Originally posted by FoxHondaRider
11:1 and up you need to run race gas. whats the stock compression ratio for a 250?

9:1, IIRC.

11:1 is the general rule of thumb, but is not always the case. depends on the amount of air flow into the motor, the amount of air the cyl head flows in and out, etc etc etc.

[rev-man]

ok what is your recommendations for more power without puttin a bigger piston in it

[bwamos]

Cam & port work for starters.

You'll probably see more benefit from a good cam and port work than you would a +0.080" piston anyway.

[ryanh250ex]

Originally posted by bwamos
Cam & port work for starters.

You'll probably see more benefit from a good cam and port work than you would a +0.080" piston anyway.

Brandon's got this one dead-on.

WEB Cam, port and polish, or you could throw in a bigger carb. keep in mind that with a bigger carb you will have to either modify your airbox, or delete it altogether. For headwork I would recommend Killian's Porting Services. http://www.killiansportingservice.com/

[rev-man]

thanks i prolly wont do that til may be a year from now or so

[rev-man]

ya but the web camshaft i found is only for the 2000-2003 model will it work in my 07

[250ex/ttrpimp]

:p a web cam will work for your mom

[rev-man]

you better shut up for i whip yo *&$

[prairiemonster]

My grandson has a 280 thumper racing piston in his quad.He has not race tested it yet but on our mx track it has lots of torq.It will take off in any gear and do second gear wheel stands forever.As for hp or top speed we just do not know yet ,should have it dyno tested real soon.If you want more info or numbers just ask.
A few things he has:
DG front bumper,nerfs,pipe
AC grab bar
6" diamond j
elkas
pro-com
vapor
gel grips
douglas rims
itp tires-gncc,sx,mx4,rs
thumper 280 piston
30 shot boss-noss
custom-head port,cam and springs,steering stabilizer
TOO SICK TO SHOW!!

[07250ex]

Originally posted by 250ex/ttrpimp
:p a web cam will work for your mom


wow you can tell this ones a winner :rolleyes: first post hes alredy dissin someones mom

[ryanh250ex]

Originally posted by prairiemonster
My grandson has a 280 thumper racing piston in his quad.He has not race tested it yet but on our mx track it has lots of torq.It will take off in any gear and do second gear wheel stands forever.As for hp or top speed we just do not know yet ,should have it dyno tested real soon.If you want more info or numbers just ask.
A few things he has:
DG front bumper,nerfs,pipe
AC grab bar
6" diamond j
elkas
pro-com
vapor
gel grips
douglas rims
itp tires-gncc,sx,mx4,rs
thumper 280 piston
30 shot boss-noss
custom-head port,cam and springs,steering stabilizer
TOO SICK TO SHOW!!


hmm, that sounds pretty cool. You're gonna have to show us a pic though.

Did the thumper racing kit come with a bigger cyl sleeve? there's no way it is 280cc's on boring alone, unless they made a new liner...

[prairiemonster]

The new piston is 74mm,factory is 68.5mm it takes a new sleeve for sure!The sleeve is made by Advance $140 installed,piston is a
Wiseco#10397M07400 / trx250ex2006 11:1cr/piston kit $325.The gaskets are about $50.Thumper Racing did a nice job on the cylinder and they will port the head for$200.They did not port my
grandsons head because we thought the price was to high for just a basic clean up,not a true port or flow port.
Anything else?

[tedwilley]

Nice info, thanks!

[klutchbuster250]

can u give us a link to there website?

[tedwilley]

http://www.thumper-racing.net/kits.html

No specific 250ex 'kit' shown, but they also sell indivdual parts.

[prairiemonster]

I know they do not have the 280ex kit up on thier site you have to call them at 903-938-3340 and ask for Hazel.They must sell alot of them because I had to wait for the scond run of pistons to get mine.

[250ex/ttrpimp]

me and rev man r tight and ride atvs with each other alot:blah:

[rev-man]

will that kit spank a 300ex

[Hondamaster5505]

whats the point of boring and stroking a lawn mower (no offense)

Save your money, sell your 250, and get a 300ex or 400ex, you'll be much happier

[tedwilley]

WTF?
Schizohrenia?
"Hondamaster5505
Huge Yamaha guy"

[TRXRIDER4567]

yea wtf

[tedwilley]

Yeah, me too.:cool:
The lil' 250ex and a Cannondale 450 stroker (Jekyll and Hyde)

[Hondamaster5505]

Originally posted by tedwilley
WTF?
Schizohrenia?
"Hondamaster5505
Huge Yamaha guy"

I always loved yamaha the most and honda second, i just got a good deal on a 400ex so i made my name hondamaster5505.

Really i like yamahas more, and the new 2008's hondas helped that even more

SO yeah, im a bigger yamaha person, and most likely my next bike will be a yamaha

[prairiemonster]

[QUOTE]Originally posted by Hondamaster5505
whats the point of boring and stroking a lawn mower (no offense)

Save your money, sell your 250, and get a 300ex or 400ex, you'll be much happier [/QUOTE
The point is I had to bore the ex to 280 to beat my lawn mower that does over 50mph !!! It is a honda too.
The main point at that time was not to send 12 year old kid into the race world on anything bigger than a 250.He has been riding a 250 since he was 8 now going on 14 he is just now at size and weight level to make the 280 do what he wants it to do.
At that point a whole new level of fun begins.One more thing to point out is the sportclutch system,nobody says much about this set up, that's a shame.It is a real good system that works great and will let you do things that can't be done with a normal clutch.
Decided to do the 250ex project because of the above and the fact that not much has been done on 250ex except bolt on stuff.
250=FUN

[Hondamaster5505]

yeah, but my point is, why throw money into a 250ex??

You might as well build up a recon, because that what the 250ex is. Don't get me wrong, the 250ex is great for beginners, but if he obviously wants more power, get a larger cc bike that has better handling too. if hes 14, a 300ex is much better handling and more powerful, and after that he can get a 380 big bore or a 400ex

[prairiemonster]

Originally posted by rev-man
will that kit spank a 300ex
Wow, that's a tough one with only 6cc differance between them
I would say the 300 for now just to keep peace.It should be close
like photo finish close.I do know that it will outrun a certain 250x
by about 3 quads in a 300ft drag race that used to beat the 250ex by about the same 3 quads.Finding a stock 300 to race would be the hard part around here,where are them 250 raptors when you need one. lol!

[tedwilley]

prairiemonster, you've got the right idea IMHO. Let him completely outgrow the 250. There are plenty of kids on bikes that are too big for them, but until they hit a straight section my son can out ride them and hold them off on our 250. Mine will be ready for something bigger maybe next summer, but no way I would waste money on a 300ex (No offense to any owners out there). They ride just as crappy as a stock 250ex and they are not really a big enough step up in power. We'll go with at least 400cc. When they spend the time to ride to learn and learn to ride, they'll be able to spank these other kids! 9 out of 10 young kids (average sized 12-14 yo) can't ride the bigger bikes unless they are on a straight away.
Again, no offense to those who can ride, I just see a lot who whined until their parents bought them a big quad before they were really ready.

[Hondamaster5505]

im only 14 and have a 400ex, but i just happen to know how to ride pretty well. In time, im sure your son will be bugghin ya for a bigger bike

[Honda10]

I have to say something, i dont see why people say to move to a 300ex it is pointless, throw a pipe , airfilter and jet a 250ex and you can keep up with and beat a 300ex. Plus a 300ex dosent even handle better, they arent even any winder or longer then a 250ex.
so if someone has grown out of a 250ex then it is a better idea to get 400ex or 450r.

[prairiemonster]

Originally posted by Honda10
I have to say something, i dont see why people say to move to a 300ex it is pointless, throw a pipe , airfilter and jet a 250ex and you can keep up with and beat a 300ex. Plus a 300ex dosent even handle better, they arent even any winder or longer then a 250ex.
so if someone has grown out of a 250ex then it is a better idea to get 400ex or 450r.
I agree the 300ex is not any better than the 250ex plus it cost you a extra grand.

[Hondamaster5505]

ok, well older 400ex's are a dime a dozen these days with all the 450s out.

[Honda10]

Originally posted by prairiemonster
I agree the 300ex is not any better than the 250ex plus it cost you a extra grand.

exactly, with price difference of a 250ex and 300ex you can modd a 250ex to the point where it isnt even a race.

[rev-man]

here is my ride

[250exkid]

Hondamaster5505
you are correct in every way! i was 15 when i bought me new 2005 250ex. and just befor i turned 16. with i did in november of 2007 i bought a mint 2003 400ex. iv learned to handle the 250ex and id have that taped out every were! so yea id say i wasted some money puttin parts into my 250ex that i should be puttin in my 400ex, heres a pic of me on my 250ex a couple months after i bought it in 2006

[250exkid]

another

[250exkid]

what i bought and will never regret!

[Hondamaster5505]

YES! finally someone that agrees.

You can find nice 400ex's these days from $1500-$2000, the same price as the 250ex's go for:ermm:

Just go 400ex, its not worth putting money into the 250ex, because it still wont be as fast as if you put money into a 400ex..

[250exkid]

hell ya i agree 100% i should have never bought it.. but then again ya gotta start some were, but i shoulda never put performance on it, cuz then i could afford the sparks for my 400ex, my sparks on the 250ex i picked up a 200 used one. so i cant complain on that price! but hey

[stew21]

i could say the same thing about a 400 though why not just go with the 450 then. cause a 400 will never be as fast as a 450.

[Hondamaster5505]

Originally posted by stew21
i could say the same thing about a 400 though why not just go with the 450 then. cause a 400 will never be as fast as a 450.

450's are way more expensive then the 400ex, thats why.

Not only is the 400ex the same price range as the 250, its faster, handles better, and just a plain out better bike.

The 250 is good for a beginner, but not worth putting money into.

[250exkid]

there again i agree 100%!! for an extra 50cc and liquide cooled it aint worth the extra couple thousand dollars

[Hondamaster5505]

Originally posted by stew21
i could say the same thing about a 400 though why not just go with the 450 then. cause a 400 will never be as fast as a 450.

Another thing to add.

Ive seen 460 stroker and 500 stroker 400ex's on juice putiing out in the 70's, thats more then enough to outrun a piped 450;)

[stew21]

I understand completely what your saying, that a 400 is better than a 250, but what im trying to say is if your going to buy 400 and put money into it you could of just bought a 450. I own a 250 400 and a 450 and ive put alot of money into them all, not so much the 400 yet. So Im into putting more power into anything.

[stew21]

Im not an expert here by any means but I highly doubt you can get 70 hp out of a 400. I have on my 450 with a 480 big bore kit, high compression piston, kibble white valves, ported polished head fcr carb, full exhaust and im probably only in the mid 50s. Its a 05 honda by the way. If you can get 70 out of a 400 it would have to cost alot of money.

[m.h.s.c.#527]

alright not 1 of the last 10 posts has answered this mans question get back on topic

[stew21]

Sorry for getting off topic i just hate when people say to just buy a bigger quad. I was just trying to prove apoint to those guys saying just buy a 400. But anyways I know you didnt want to know about the powroll big bore kit but my wife absolutely loves hers. She also has a 27mm carb Hmf exhaust and soon a web cam. It made a huge diffrence, I even like to play on her quad sometimes.

[Hondamaster5505]

I was just making a point that 250ex's arent worth modding.

Your way better off just going to a stock/piped 400ex.

And the setup i mentioned on the 400ex means its also running juice, which already bumps up 20hp;)

[BlasterEaten250]

Originally posted by Hondamaster5505
I was just making a point that 250ex's arent worth modding.

Your way better off just going to a stock/piped 400ex.
I'm very glad I didn't start on a 400. I learned A LOT about riding on the 250ex.

I agree, the 400ex is superior in handling, power, etc., but it's their life and let them do what they want. If they want to modify their 250, let them. I put some money into mine and I don't regret it at all.

my little rant, continue on:D

[Hondamaster5505]

Originally posted by BlasterEaten250
I'm very glad I didn't start on a 400. I learned A LOT about riding on the 250ex.

I agree, the 400ex is superior in handling, power, etc., but it's their life and let them do what they want. If they want to modify their 250, let them. I put some money into mine and I don't regret it at all.

my little rant, continue on:D

Im not telling him what to do, im stating my opinion on whaty he should do.

Yes, the 250ex is a GREAT learning bike when it comes to riding, but thats it. Otherwise its not worth going into big bore kits and such.

I understand if your doing a simple pipe/cam/filter though.

I became a bettr rider from riding a 250ex and mastering it i mean mastering where I would keep up with my buddies on their 400ex's. They would sure as hell kill me on the straights but I would get them on the turns and tight parts because the 250ex isnt as wide. But because I mastered the 250ex when I moved to the 400ex I just gained more skill and I can keep up or beat some people that have a had a 400ex for 3 times as long as I had mine. Learn everything you can about riding on a smaller quad. Theres really no sense in getting a 400ex or 450r if your not going to jump and go fast. The 400ex was made to be the ultimate trail quad and would be a waste if you just putted around or didnt go fast. On a 250ex jump it, climb hills, fly around turns, try and fly over whoops and now you have learned what to do in all different situations and your ready to move up unless your comfortable on the 250ex. Add a pipe to a 250ex and it really wakes up the motor. Stock the header is pretty small and makes it underpowered. I'm not so sure what you guys are saying about the 300ex being worthless because for that extra money it has a gas filled body preload adjustable rear shock with more travel, and front shocks with more travel, its faster, wider and longer wheelbase than the 250ex. So the 300ex isnt useless its just kind of the inbetween man. 250ex I would suggest to anyone that wanted to start riding on a Honda. 300ex I would say is for those who are either stepping up from a 250ex or moving from having a smaller quad that had experience in riding before. The 400ex is quite a big step from them all. It deffinately requires riding skill perviously to be able to control it and it not controlling you. and the 450r ah how could we forget that, its downright a race machine that needs to go fast.

[07250ex]

Originally posted by Hondamaster5505
450's are way more expensive then the 400ex, thats why.

Not only is the 400ex the same price range as the 250, its faster, handles better, and just a plain out better bike.

The 250 is good for a beginner, but not worth putting money into.

not really for new bikes 450's are 1000 more than 400ex's yet 400ex's are 2000 more than 250's

[Hondamaster5505]

Most people dont buy new bikes.

Im talking the used market.

450r isnt for everyone though. If you race MX get a 450r if you want to do everything get a 400ex. 450r can be made to do all the stuff a 400ex can but it just isnt as fun. My friend always had 400ex's, he decided to buy a 450r and a few months later he sold it and bought another 400ex. 450r is made to race on a track and if your not racing theres really no point in having 1

[Hondamaster5505]

Well, dont know much about 450r's.

But when i rode that 07 yfz450, i took it through a small trail section.

The yfz has such an excellent mid-range and the suspension actually felt nice in the trails.

Especially when your flying down them.

It still had a race bike feel but not to the point it isnt comfortable in the trails.

ride it in tight trails though and there not as much fun

[Hondamaster5505]

Originally posted by FoxHondaRider
ride it in tight trails though and there not as much fun

i was in some tight stuff.

Its still stock width, which isnt super wide for tight trails.

He probably would have to drop the sproket 1 tooth though. The gearings a tee too high on them.

[culichi]

but the topic isnt about this its about the big bore kits and if someone wants to spend alot of money on a 250 its not to try to beat a 400ex its just because they like their ride and can spend that kind of cash on it.... im planning on sending my whole 250ex motor to thumper and have them put on the big bore and port it and all because i want my brother to have a really nice ride and i could spend that money on my ltr but im doing it on the 250ex....



PS: i even bought hipers all around to make it really stand out and im planning on some a- arms and an axle to make it the best quad for my brother (and i like to mees around with it hahahahah)

Originally posted by Hondamaster5505
i was in some tight stuff.

Its still stock width, which isnt super wide for tight trails.

He probably would have to drop the sproket 1 tooth though. The gearings a tee too high on them.

yah thats the main problem is them being geared to high and having to rev so high. 1 tooth down on the front and its great! 450's still arent play bikes they arent as much fun for dicking around

[maddmatt02]

Originally posted by Hondamaster5505
Another thing to add.

Ive seen 460 stroker and 500 stroker 400ex's on juice putiing out in the 70's, thats more then enough to outrun a piped 450;)

yeah, but a 460 with P&P, HC stg 2, fmf full system, no lid, K&N still gets barely edged out by a piped YFZ, now with a FCR the 460 can walk from it barely.

but the money it took to build that bike you could have a YFZ and some change, and then adding nitrous to the bill you could just put a high cr piston and cams in the 450, pipe it, rejet and walk from the 460, maybe not with nitrous, but his bottle will run dry and you cant buy that stuff at the gas station around the corner from the dunes. so once your out, your out and now have no chance of beating the 450.

and about people complaining about gearing on the 450's, a front sprocket costs what, 15-20 bucks and its now geared just how you like it, you should feel lucky, only way you can do it on a 250ex is with tire size, and they already got 22's so with more power you dont get to add more gear....... thats my biggest complaint about the 250ex, I think they are fun, but that gearing thing is another reason not to mod em, stock they pull the gearing absolutely fine. sure some more power would be welcome but out in the open you can never gain more speed really. Id rather do it by more power, taller gears and rev the same going faster, not more power to pull higher r's and raise the limit.

[ONAGER II]

very long quote (LOL), i completely agree. although i learned the basics on a sport trax 90, i learned how to rip through trails and be competitive on my beloved TRX250EX. i am planning to upgrade it to hope to take on my friends 300ex on the drag and trail courses. my brother has a 400ex, and although it is faster, i would not say it has better handling. it is wider, and has a smaller turning radius. but, it can pull a 180 power turn quite easily. :D

[ONAGER II]

Originally posted by FoxHondaRider
I became a bettr rider from riding a 250ex and mastering it i mean mastering where I would keep up with my buddies on their 400ex's. They would sure as hell kill me on the straights but I would get them on the turns and tight parts because the 250ex isnt as wide. But because I mastered the 250ex when I moved to the 400ex I just gained more skill and I can keep up or beat some people that have a had a 400ex for 3 times as long as I had mine. Learn everything you can about riding on a smaller quad. Theres really no sense in getting a 400ex or 450r if your not going to jump and go fast. The 400ex was made to be the ultimate trail quad and would be a waste if you just putted around or didnt go fast. On a 250ex jump it, climb hills, fly around turns, try and fly over whoops and now you have learned what to do in all different situations and your ready to move up unless your comfortable on the 250ex. Add a pipe to a 250ex and it really wakes up the motor. Stock the header is pretty small and makes it underpowered. I'm not so sure what you guys are saying about the 300ex being worthless because for that extra money it has a gas filled body preload adjustable rear shock with more travel, and front shocks with more travel, its faster, wider and longer wheelbase than the 250ex. So the 300ex isnt useless its just kind of the inbetween man. 250ex I would suggest to anyone that wanted to start riding on a Honda. 300ex I would say is for those who are either stepping up from a 250ex or moving from having a smaller quad that had experience in riding before. The 400ex is quite a big step from them all. It deffinately requires riding skill perviously to be able to control it and it not controlling you. and the 450r ah how could we forget that, its downright a race machine that needs to go fast. quote was 'posed to be on my first post

[01exrider 281]

To the oringinal poster, I do not have experience with the 250 so i can't say anythin about it. but with a few things done to it i think it would be a great quad to rip around in the trails. plus there are low maintence, shaft drive and the newer ones have that clutch which would be awsome to have. If you want to do things to ur quad and that is what u want to do to it then do it. ppl sayin just get a bigger quad is pointless. my friend has a 450 and i can smoke him on my 300 bc he cant ride so if you cant handle the power it is useless anyway.

Tyler

[01exrider 281]

To the oringinal poster, I do not have experience with the 250 so i can't say anythin about it. but with a few things done to it i think it would be a great quad to rip around in the trails. Personally I would love to build up one to blast around on but dont have the money to put into another quad. plus there are low maintence, shaft drive and the newer ones have that clutch which would be awsome to have. If you want to do things to ur quad and that is what u want to do to it then do it. ppl sayin just get a bigger quad is pointless. my friend has a 450 and i can smoke him on my 300 bc he cant ride so if you cant handle the power it is useless anyway.

Tyler

[maddmatt02]

maybe on a track, but in trails, in the dunes, anywhere where there is almost no skill involved, a 450 will absolutely demolish a 300. even a fully built 300 to a stock 450 wouldnt have a chance. Im not saying on a track someone with skill, good suspension on a 300 couldnt beat someone on a stock 450 w/ stock suspension and skill on a track, but its hard to believe anyone on a 300 would beat anyone on a 450 anywhere else...

[01exrider 281]

if you saw the one kid that i ride with tht has a 450 you would see how. he just cant ride the thing the way most people can and dosn know how to handle it. but take it to a place where top speed is a issue then it is diff but trails and track i can take him. an i am not saying i beat 450s i am sayin i beat him on a 450 but put a good rider on it and then things change