[kenciavatta]

Going through a 400ex ....need to know where to buy Honda original valve stem seals online preferably , and what valve spring compression tool kit will work and work best....dont know what mm is needed....kits come with 16mm, 19mm, ect... only need for motorcycles...no cars. Also are those Niche 440 big bore kits ok to run?....I know they bump up compression to 10:1 or more.....big bores are cheaper than stock 85's.....MAHALO for any help....Aloha

 

[SlammedRanger]

I usually get my oem honda parts from rockymountainatv/mc. But i have to ask why oem valve seals? These are a very basic part that any aftermarket one is going to work just fine. Im partial to cometic personally. But the problem your going to have is removing the springs with the head still on the quad. Havent seen a spring compressor that will work yet. I change them with the head off with a jaw type compressor that holds the valve from the opposite side and a magnet to grab the keepers off the top side through what pretty much looks like a socket with 2 sides missing. The niche kits are cheaply made. The cylinder dosnt even have a removable sleeve. 440 kits are unreliable as a whole. I personally wouldnt trust niche somehow got it right. CT racing makes the only 440 kit thats as reliable as stock and they sleeve and o-ring it. And they also use a custom milled jug with deeper and wider air cooling fins.