440 Big Bore Kits

[EXriderKID00]

so can someone honestly tell me are the 440 big bore kits a good investment espically since i have an 01 400 ex? n also tell me how are they are to do it yourself n how i should cut my front fenders THANKS

[DH400EX]

get it - dont do it urself - cut ur fenders if ur racin MX, if ur racin XC u can if u dont mind a lil extra mud.

the 440 is def. worth the money, as for the fenders get some electric tape and outline the shape you want on each side and hit it with a sawsall or a jig saw then with a file to smooth the edges then sandpaper and finer sand paper then steel whool and finaly get a heat gun or a torch and melt the edges to make it look factory

[jonny2stroke]

I will be investingin a 440 kit anybody have any bad luck with the 12.5:1 pistons. I was also worried about overheating. I know jetting will be a major factor and I will also replace the carb so the big dog can breath.

[EXriderKID00]

see because one of my friends is hookin me up with a 440 big bore kit for 100 bucks so i'd like to know how good they are ups and downs of them before i invest because me and my other buddy hvae already put a bore kit in a XR70 and were ready to see what other big projects we can do...

[Joe400ex]

i herd they do run extremely hot but i have the same / because i want to do the same bore. also if that bore blow what do u do next a 465. thank u

[FoxRacing81]

Originally posted by Joe400ex
i herd they do run extremely hot but i have the same / because i want to do the same bore. also if that bore blow what do u do next a 465. thank u

If you ruin the 440 sleeve, you resleeve and bore it out to a 440 again. I'm pretty sure only way to get 465 is by stroking it, but I'm not 100% sure.

you will def. need scoops and probly an oil cooler if you dont have them already but i dont think a 12.5:1 piston is a good idea, ive heard about people pulling head studs with those compresion ratios i think you would be better off with a 11:1, those rev faster ne way

[K_Fulk]

Originally posted by Joe400ex
i herd they do run extremely hot but i have the same / because i want to do the same bore. also if that bore blow what do u do next a 465. thank u

For a 465 sleeve you will need and even bigger sleeve then a 440 sleeve. You need to bore the engine cases so the 465 sleeve will fit in the motor.

465 bore= 92mm piston
435 bore= 89mm piston what most people use as 440 kits
real 440 = 89.5mm piston

[Jonas]

My 440 lasted for three years until I sold it. I have one for sale at my dealership for cost if anyone is interested. It is a IMS 440 kit with a JT piston and LA sleeve. Very good kit!

[440bigborekit]

i been running the sparks 440 national and had no realy big problems sence i got it except for keep in the motor cool u def need air scoops . i also got the k&n powerlid and the thing runs like a champ i would would say get the 440 kit u wont be dissapointed wit it. but i would ask instead of 12.5 -1 like they advertize on the site to get a 11-1 instead. the hood i got helps to ,quad tech makes a realy nice hood.

[darkstar]

would about puting new head studs in. sunds like not to many people do that. Do you really have to?

[K_Fulk]

I never had to get the studs on my 440. But some people have chronic head gasket problems.

if you use a 11:1 piston you shouldnt have to

[nowukno]

I would recommend the 416 bore , one of my friends has a piped/jetted 416ex with a je 10:8:1 compression piston and a stage 2 hotcams and it rips. He can run neck-n-neck with another friends piped/jetted raptor. Ofcourse the raptor pulls away further the longer the race is. But im not worried yet , since neither one can touch me.