1 quick ex

Tell me this, you said you have a 11.25:1 piston. What name brand? Do you run race fuel? Where can I get my hands on one?

 

I have a lightened Ross Racing piston from CT Racing that is actually an 11:1 compression ratio, and i also put on a head gasket out of an XR 400 that is a little thinner( about a quarter point). I still run premium pump, but put some octane booster in each tank of gas just to be safe. No problems at all, and the bike rocks! Good luck.

 

on the 440 kit you take old sleeve out.. ...bore cylinder for seeve install new sleeve ... FINISH BORE the sleeve to fit piston...i would suggest decking the head....

 

Your dealer isnt telling you all. First off, did you get the extended warranty? because you pretty much kiss it goodby. (add 500.00 to your engine kit now.) Next, the 440 is going to give you a totally new machine. The power you gain is way above 1/2 horsepower, even above 3/4. With the pipe, and any extras(jetting, porting, pipe, air filter, gearing) you have altered the machine to be totally different. I went up one tooth on the front sprocket, down one on the back, and it still has no problem pulling wheelies, and pulls extremely strong through all gears( rev limiter STOCK) hitting revver in 4th, and 5th, well i havent got enough straightaway to find a maximum top speed yet. I havent run it against a built banshee or raptor, but I know i wont be dissapoited in the outcome. Ill be fast enough. Next thing,can you afford it, and can you control it? good luck. (also keep in mind, unless your a serious MXer, stay away from race gas.

 

What to do? Wish I had an answer for ya. These guys obviously have the answers. 1quick EX is right it'll love more octane after the mods.I never rode the 416 or 426 but Thumbthrottler and 1quickEX is right it'll be totally different with the 440.It's gonna PULL the whole way through and I don't mean gradually either. You make your own choice I went with the 440 and da-n glad I did. 2000 400Ex IMS 440 BIGBORE KIT, WB cam, Dynojet 155, K/N, 17 tooth front stock rear sprocketts, Ported, Polished, WB E-series pipe, rev box, Shredders, ITP's, Renthel bars, Maier grips and guards, SKIN graphics, 116 CAM 2 cut 50/50 with 94 pump gas for fuel.That averages out to about 105.It loves it.Strait 116 for drags. GOOD LUCK and let us know how you make out.

 

Higher compression is where you gain your power, not the couple extra mm bigger piston.sure you gain a little power with a bigger piston, but like i said, i can't believe what just a high compression piston and cam did for me. I ordered a 416 piston through CT Racing, but they sent me the stock size piston. i was tired of not being able to ride so i told them that i'd just keep the stock bore 11:1 piston that they had sent. My next piston is going to be a 12:1 87mm piston. this piston will require 105 octane, but will be well worth it.

 

Hey, I'm still comptemplaiting the kit. How much was your total cost. Have you noticed any engion wear since your kit was added? Did you have it Professionally installed? And finally, Have you ever "Dragged" against a modded banshee? How did you do. Any other information I should know about? You guys are awesome, thanks alot.

Also, Where do you put the oil in for a crank change, I can't find it.

Thanks
Derek

 

My IMS 440 11:1, Ported, hardend rockers, web cam 415/450 (?) grind, WB R4 slip-on, K&N, Dyno Jet Kit, Gunner tether and a XR250 cdi cost me around $1500 including labor. Geese.... I can't believe I spent that much. It will add up on ya.

The oil goes into the oil reservoir in front of the engine (2 qrts).