THE TOP END ON MY 400EX IS GETTING WEAK. 27% LEAKDOWN, THATS NOT GOOD. IVE BEEN THINKING ABOUT A 440 KIT WITH NO MORE THAN 10-1 COMPRESSION.I RIDE THICK TIMBER AND WAS WONDERING IF OVER HEATING WOULD BE AN ISSUE. IT HAS A XR400 GRIND CAM IN IT THAT A COMPANY CALLED PIVOT WORKS IN IOWA IS GOING TO MARKET SOON , IT ALSO HAS THE BASIC MODS ON IT (FMF PIPE AND WHITE BROS REV KIT). THATS WHAT ITS MADE OF. SO IF ANYONE HAS THE SAME SET UP I AM VERY INTERESTED IN YOU OPPINION. THANKS

 

I am not the smartest person but from what i have seen in the dunes, which u obviosly dont ride my friends 416 keeps up with all 440s out there. I have never been real impressed with white brothers stuff. I have one of there pipes and the bracket that holds it to the frame broke after 1 ride and so forth. If i were you i would go with a local shop or send your motor out. I had my motor done by LRD and i am very pleased with he results. They are a well established company that has benn around for a while now. Personally i dont like WB to much. But for the woods a 440 is the way to go because of the torque. But in my opinion stay away from WB. I guess i am just prejudice. oh well. just my 2 cents

 

I'm not very impressed with WB either. Bought a WB E-Series for my 400EX about 7 months ago. I had to have the bracket the holds it to the frame re-welded and just recently the actual silencer broke away from the pipe it's welded to. Pretty poor craftsmenship if you ask me. You spend $250 for something, it should hold together for a while.

 

Friend of mine use's a Poweroll 440 set up. Very fast and reliable, we also do alot of deep woods riding. Give Poweroll a call doesn't hurt to talk to them. I've got a TC 416, this is also a great machine the big difference between the two is the 416 revs quicker. Hope ya don't mind me buttin in.

kutchd

 

Do you have any overheating problems with the 416. That doesnt need a sleave but wasnt the sleave paper thin down at the bottom of the bore. I heardthat some people were having problems with distorsion at the bottom of there sleaves

 

No haven't over heated yet, I always change the oil after every ride seems to make the difference (it's schafers 40 weight racing oil). I've been searching for the "Perfect Ride" you know what I meen, I've had built Banshee's for both top and bottom end, just got rid of a screem'n 250R last week, stock 400's with jet kit and pipe (not enough top end but great for rock & hill climbing), friends 440 lots of torque and fast, the 416 is torque'e and also rev's quick so far I'm preity impressed with the 416.

kutch

 

I just went through the whole debate on 416, 426, 440 thing myself... I decided to go with the 426. There is ONLY an 8% difference in power between the 440 and 416. The 416 will give you a higher top speed- and the 440 will give you more bottom end torque... so if you are in the woods and doing alot of stopping and accelerating- you may want the 440.

The 426 (88mm) is the biggest size piston you can go before you have to re-sleeve. This allows you one more bore when the engine gets weak. -also- for $130 bucks and doing the mods your self- the price is much more manageable than the 440 kit.

You might want to get a valve job when you are getting your cylinder bored.

 

Hey RotGutBottom:
How do you like the E-Series pipe? I've been looking for a spark arrested slip on what's your thoughts on the E-Series. What are you running carb wise, Ive been running a Lectron and kind of want to change to the Edelbrock Quicksilver got any knowledge on them.

kutchd