I been thinkin about borein my ex out to a 440. how much faster is it and is there any down fall on the 440s? if i bore it over do i keep my stock cam or what should i do any one with info

 

dont do it unless u like spending money fixing ur engine like a 2 stroke [img]i/expressions/face-icon-small-blush.gif[/img] that is.. if u dont take care of it. what im trying to say is, High Maintenance.

 

Riderr is wrong... no offence meant...

There is no more maintenance with a 440 than with the 400. But,,, It is not cheap to do it right..
there is more to it than just resleeving and bigger piston, if you want real good gains..

First off, how much do you plan on spending, what type of riding do you do.. Those questions must be answered before you make the decision to modify...

 

I would say go for it, i just put my 440 in my bike and i love it, the top speed of course wont be any faster but you will get there alot quicker. really it wasn't all that much to have done, i bought the kit for $280 (included piston, wrings, cam, sleeve and all new gaskets. I had it sleeved and bored for $115. I could have stopped there and been alright, but i upgraded my exhaust to a full system and added air shrouds to help cool my engine but most people would say buy an aftermarket oil tank and that wil be better, but i didnt have the money to buy one. Untill mine blows something or runs like **** i will continue to tell people it is worth it to put in.

Wreckless

 

hey there - I just had to reply - - My 440 is still as reliable as a stock 400 - I have about $1000 in my motor - just make sure you don't buy cheap e-bay parts to throw in there - I used a je piston - and use the best head gasket - thats where people have prob's - my powroll has never leaked a bit - you can add alot w/ a 440 - like a 39mm keihin fcr carb to feed it and a high lift cam ( I'm not gonna tell ya' what kind I have - that's my edge over other kits) - but yeah - you will get great gains w/ a good kit - stock h.p. is like 28 and I'm at 42-44h.p. - I beat 450r's and yfz's all the time ( I'm sure they aren't built - I know my bud's aren't - but even piped & jetted ones I still walk right past) - anyways - i guess I'm just saying - if you're gonna do it , do it right and you won't be dissapointed at all - good luck

 

I agree, if done properly a 440 can and will be just as reliable as stock if it is done right. I have the duncan pc4000 porting, and all the other goodies done to mine and I have been problem free for alomst a year now, Im jsut now doing a rebuild on a few things but still didnt blow one single head gasket and my piston only needed rings replaced.[img]i/expressions/face-icon-small-wink.gif[/img] IU LOVE the top end my quad has now, its not a new 450, but its the next best thing and ... ITS RELIABLE and easy maintence... Good luck!

Tina

 

Yep if done right they are very reliable. Just dont go using a piston with an astrological compression. I have a relitively low compression piston in mine and a the cam from either the xr400 or xr650 dirt bike. I know its strange that I don't remember which one I'll have to check my receipts. All my work was done by a local race shop owner whom I trust very much. After everything is said and done I have had the kit in mine for about 4 years and it runs perfect everytime. Just have to clean the carb adjust the valves every couple seasons. Same stuff you do with a stock ex. In regards to how fast will it be? Depends on a number of things. Compression, which pipe, cam ect... Mine will easily hang with stock raptor 660's. Will beat piped Z400's but will still get beat handily by the new 450's. Course I'm over 6 feet and 225 lbs but not to make excuses or anything [img]i/expressions/face-icon-small-smile.gif[/img]

 

Hey, thats not an excuse!! Weight does play HEAVILY( no pun.. LOL!) Now if I would just shrink a little more too , I would do much better on a holeshot!
[img]i/expressions/face-icon-small-blush.gif[/img]

I run a 12:1 in mine, I was a bit nervous, I went from a 426 11:1 to the PC4000 and it was moeny well spent and I dont get near as much power robbing from overheating


Tina