leave stock or got with 416,440, big bore kit?

[T-were]

is it worth it in terms of reliability for a quad that is not being raced just trail riddin to up the displacement, i would like to get the most power i can and still run pump gas, and have in just as reliable as stock can you tell me how, am i goning to be rebilding more and more if i get it bored over. cause that is what way i love 4storkes and the only draw back i hate of 2strokes , i love hondas becasue they run forever. for example my little cousing has a 95xr100r and i am about 6'2" 165lbs. and that thing will take a beeting frome me, one time he had a gasket go bad on him and he hadall the oil drained out of it i told him not to ride it till i can fix it, so a day later he told me his dad temp fixed it and it was full of oil so i took it out for the day and piss pounded it "trying" to keep up with two of my buddies, one on a 98cr 250 amd the other on a 99 kx125 and it never acted up in any way , come to find out my cousin had lied to me and his dad never touched it and there was no, oil in it the whole time i was riddin it. i know i got of the subject but i just wanted to get you guys a idea of what imean my reliable, i want my 400ex to remain close to stock but still have balls. what is the best way for me to do this parts, oils, matinance..... i apoligive for my spelling

[cals400ex]

since it seems like durability is your main concern, i would go with a 406. make sure you add a cam to suit your riding style too. i would get a pipe if you don't already have one. you will notice a very very nice gain with these mods and still be reliable. i believe these 406's come in 10.6:1 compression, which will be good on premium fuel.

[TC426EX]

I agree with cal execpt I would say go 416 at the minimum. The 416 is a very popular size and is still VERY reliable. The cam and the exhaust pretty much have to be added at the same time to see a significant difference. Just the piston alone wont do much...

[bdrue]

does a 416 kit need to have a cylinder sleeve?

[TC426EX]

Originally posted by bdrue
does a 416 kit need to have a cylinder sleeve?

NO.... The stock sleeve is just bored out...

[cals400ex]

i have ran 406's, a 416, and a 426. the difference between them isn't that much. the 426 seemed to get hotter. i know everyone recommends a 416. i know my 406 would run with my buddies 416. my 426 doesn't rev quite as high but produces a bit more torque. i honestly loved my high revving 406. the 406 didn't seem to get as hot.

[T-were]

what is the best way to get the most power i can if i keep it 400? intake?(what kind) exhaust (im planning on hfm or sparks) (jets, what size?) and i know sprockets but i spend most of my time on trails so speeds are all over the place low in the woods through top on back roads if you have anyother tipes,tricks let me know thanx again

[nosliw]

i think you can keep the stock bore and stock sleeve and just put in a 11:1 piston? :confused: correct me if i'm wrong.

i have a kn filter, no airbox lid, hmf slip on and i'm running a 152mj, 42pj, and stock needle in 2nd clip from bottom....

[cals400ex]

a stock bore higher compression piston would be fine too after a hone, given your sleeve is in good shape. make sure you add a cam, that makes a pretty big difference. i don't consider a new filter necessary. i can't tell a difference between stock, twin air, uni, and K&N. a good full exhaust will be great for that cam and pistoned bike.

[APK400exRacer]

I am running a 400 with 11:1 stock bore wiseco piston with a wikid port and polish. It runs a little choppy with stock exhaust but it gets by. I need to get soem money to buy a cam and pipe. Personally if you ride trails id get stage 1 cam and hmf exhaust. Thats what i will do when the time comes and i have money i think. Right now mine is a sleeper :devil:

[MarkyNark]

I had the same choice about a year and a half ago. I decided to go with the 440 big bore. There are a lot of other components you have to get with the 440 that you dont with the 416. Plus, a 416 will usually perform equally with a 440 in a dune drag. Thats not to say it will out perform it everywhere else - especially where torque and bottem end power are needed.

Besides the extra dollars you need to upgrade the rest of the components, another thing to consider is where you will go from a 416.

A 465 stroker is an easy upgrade from a 440 big bore, and everything I have read seems to indicate that RWHP should be at about 50hp. Thats a pretty substainial gain - My DS is at about 55 hp now, and its pretty heavy - the 440 beats it now with about 42 RWHP.

Other components to consider with a 440 are ...

1 ) Cam
2 ) Valve Springs
3 ) Carb
4 ) Exhaust
5 ) Piston
6 ) Hard weld rockers
7 ) Shortened Valve Guides
8 ) Oversize oil tank/cooler
9 ) Race Clutch
10 ) Swingarm - at least +2"

Other things you can do to the 440 is..

1) Ported Head
2) Larger Valves

You'll probably spend another $2500 in parts for the 440 over the 416.

PS - I ride hard nearly every weekend and have had no relaiblity problem for 1 year.