namura pistons

[hondaman146]

i'm thinking about buying a 11:1 namura piston for my 400 ex and want your guys input on it as it is not a name brand like wiseco is it a reliable piston?

[CK1999.400ex]

i am running a namura piston in my 1999 400ex it has been in my machine sence the first part of the riding season (march) of this year , i havent had any problems with it . i have taken the motor apart to do some other mods (port the head and heavyduty studs) in the last several weeks ,and to my amazement the teflon coating is still intact , it has been ridden all season and it still has about the same compression as when i put it in (only about 1 lb lower than when put in ) that is not enough difference to worry about. it could b the difference in the new head gasket or just minor wear in the cylinder or the valves or who knows . but in my opinion they are not a bad option and the price isint bad earher . but that is the results that i hav had. i also run mobil 1 syenthetic oil in my machine . so i hope this has helped and good luck with your rebuild :blah:

[dariusld]

I think the Namura is a heavy piston. I would spend the extra money and get the Wiseco. And this is coming from a cheap skate.

[CK1999.400ex]

i have used the wiseco pistons in the past and i WILL NEVER USE THEM AGAIN !!! i have not had any luck with them they have a problem with swelling when they get hot and will wear out the cylinder and the piston way be for they should!!! i run a digital oil temp on my machine and it runs cooler with the namura ... the last piston i had in it was the wiseco . and never again !!!it only lasted 1 season. heat is your enemy on the 400ex motor they run hot when they are new and even hotter with the wiseco... i have built several atv engines (30) and i have used je's and stock brands eversence till i built my 400ex this spring and its running fine and the weight isint noticible .

[2muchquad]

its running fine and the weight isint noticible .

Exactly :)