question about 250r / cr 500

[gasmask]

what modification is needed to put a 500cc motor on a 250r frame?

[200x Basket]

a lot of mods. you can either cut your frame and modify it several ways or you can remove part of your frame and clearance the tubes to make it fit. Some people (Mr.ATC) says the last method it a death trap. 250rmad on this site has had one like this for years with no ill effects. i built one last year using the same method and it worked fine. I have the frame for sale on ebay right now. there is a pic of some of the mods. look here to check it out.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=10066&item=24 29352069

[MR ATC]

Basket, please stop putting words in my mouth.

i did not say 250Rmads/Kasey's and your methods are death traps. i said, that that method weakend the frame and that if i were to ride it i would brake the frame. i even showed a picture of a stock frame with those braces still intaked broke just like i said could happen. there is a better method to doing the install without weakening the frame. it is more involved but it is the best way to install a 500 in a 250 frame. you are correct that Kasey's has lasted years but you forgot to mention it is primarally a SAND trike.

the big holdup is the exhaust port is higher on the 500 motor vs. the 250 motor. the best way to install it in the frame is to raise the downtube/lower cradle joint section on the front of the frame.

[200x Basket]

Basket, please stop putting words in my mouth.

sorry, i was just trying to let him know there was more then one way and that some people felt one way was better. i have read your and kaseys debates over this and you seem to be totally against it. no offense meant torwards you.

[KASEY]

. i even showed a picture of a stock frame with those braces still intaked broke just like i said could happen.

lets make this clear for everyone. your opinion of broke and mine are two different things. when you say broke i expect to see a broke in two frame. what is in the pict is a frame without a skid plate with the frame tube smashed flat from crashing into something ,,, i see no breaks in the frame at all ,,,, just some distortion and flattening so maybe you could edit the pict and point out the broken part ,, cause i don't see it...... thanks!!!!!

[MR ATC]

Kasey you just keep running your mouth and ASSUMING without knowlege. first of all the skid plate WAS on, i repeat it WAS on. it got ripped off. i TOLD you this before. as far as what is broke, the frame cracked just after the weld on the main section going into the rear cross member. also this was not a crash nor a one time impact. it was from bottoming out on a jump. the first few impacts the skid plate took the abuse but after time it was slowly destroyed followed by the frame rails.

what you have failed to do in this continuing debate is explain what would happen to your frame had it sustained such impacts.

again i will say this is not the best method for installing a 500 in a 250 frame. it is the easiest.

i have been involved in putting big bore motors in 250 frames since before 500's were around and we used CR 480's. the LAST thing you want to do is remove a main support strutt and install a bigger more powerfull motor that vibrates more then the 250. it's common sense.

the two best ways to install a 500 motor is to raise the main downtube/engine cradle section or to graft a cr500 entire engine cradle downtube section onto the 250 frame. yes it requires more work then just removing frame sections but it is the strongest way.


hmmm seems like some others agree. 9.98 for a 250 frame modified Kasey's way.

[Billy Golightly]

Guys this arguement has been gone over and over and over elsewhere, I don't care if you guys can try and act like civil people and work it out here, but the first time I see a cheap shot from anyone the thread is gone and if its a severe enough one the person in question might get some extended leave. Keep it civil like adults and it'll stay open though.

[KASEY]

I am merely showing that there are more than one way to build things ... its very simple ,,, obviously the type of riding i do is not as ABUSIVE as other people ,,,, my frame is holding up just fine in several years of riding . i have ridden hard enough to bend axles and twist swingarms on the 500 ,, so it has seen some action ,, its not a putt around in the sand machine,,and believe me the dunes are not flat smooth and easy,, there are natural jumps hills and bowls that rival any motocross tracks,,,, so its proof that the way i built it will hold up to a certian amount of punishment without a failure. its that simlpe!!!!! my design works,,,,,,,

now if someone came on the board going to build a full on moto cross machine (even thoo there is not many places to race it) my response might be different on how to build it like i said 50 times "I am merely showing that there are more than one way to build things "

[MR ATC]

and like i said it is not the BEST method and has potential for failure.

[KASEY]

and like i said it is not the BEST method and has potential for failure

OK thats your opinion,,,,, then you have to say the same about the 85-86 atc 250r frame ,,, its not the best and has a potential for failure ,, if you broke it,,,, then no frame is the best and ALL frames have the potential to fail,,,, so that puts me in a rather large group,,, i feel pretty safe now.... maybe a factory recall is in order...........

[CHAINSAW]

punch him in the nose!!

[MR ATC]

Kasey give it up you did it the cheap and easy way plain and simple. and untill your trike leaves the sandbox and you test it in ALL conditions you can not say for fact it will hold up. i on the other hand can say it will NOT hold up because i HAVE broken frames WITH the support. therefore it is safe and ACCURATE to say if i can brake a frame WITH the support i should be able to brake the frame WITHOUT the support. which was how this all started when i explained to you OVER a year ago that i could brake a frame like that.

you have also failed to answer a question i have asked you at least a 1/2 dozen times...what is your opinion of what would have happened to the frame i cracked had the support NOT been in place

[350x'inNY]

delete

[KASEY]

WELL HERE IT IS IN ALL ITS WEAKNESS,,,,,,,, STILL TOGETHER AFTER ALL THESE YEARS............ CHECKMATE!!!!

[MR ATC]

checkmate my trailprotrailprotrailprotrailprotrailpro. lets review this debate.

i am sticking to the basic's and avoiding the off topic remarks

a member (Basket) asks about installing a CR 500 motor in a ATC 250R chassie.

Kasey explains his method and his experiance with his machine

MR ATC post a thread explaining that while Kasey's frame works and has had no problems it is not the best way to do the conversion. MR ATC also provides an alternate way to do the install Based on his expewriance building them

Kasey takes this as an insult to his design and fires off at MR ATC saying he has no proof of this.

MR ATC explains that although Kasey has had no problems with this if he ( MR ATC) were to ride the ATC he could probably brake the frame within an hour of hard MX use. He ( MR ATC ) said this knowing that it is indeed possible because he has broken stock frames that still have the brace in question

Kasey can't beleive it is possible to do so because it has not happened to him

MR ATC post a picture of a stock 250R frame damaged in the very same area in question.

Kasey still can't believe it is possable. it's good for him so it must be good for EVERY one else.

MR ATC NEVER said Kasey's frame was not good for him ( Kasey). MR ATC said HE ( MR ATC ) could brake the frame.

Basket list his 250R/500 frame on EBAY. it is built like Kasey's Frame.
it sells for a WHOPPING $9.98.


HOW IS THAT CHECKMATE