mcx turbo sputtering midrange

[aart]

08 nytro with 270 kit at low boost. anyone have to replace there controller? how much is a new controller? prince george yammaha not open till tuesday so should i ship to them or is there anyway to unhook the turbo to see if that is the problem? i mean like un hook the air intake and then undo the wires to mcx fuel injectors? hate to find out its the main engine after all the time to ship and get back. oh the problem is not full boost its in the lower end and midrange, sputters and farts around till you mash the throttle. then runs hard for a bit and starts farting around again. a/f is low 10's. thanks in avance for any ideas.

 

[Moosehumper]

Sounds like a leak somewhere in the vac/boost line to the control box maybe?
It doesn't take much..

 

[aart]

i have tied a shock pump into the line comming off the carb, at 2 lbs the motor starts getting rough and by 12 lbs floods out. no pressure loss till air is released. is there other ways to check?

 

[Washy]

If you pump up the line going to the MCX box and it floods the motor it sounds like it is working fine. So it runs perfect under boost but off boost it runs like crap??? If this is the case. Is this a new install or has it been installed for a while.

 

[aart]

has been installed for 2 years, but i keep changing things. wondering if i take off the bov. so it can't boost and discontect mcx box if it might show if it's box or stock ignition? frigging sucks not having a dealer within 2 hours that knows mcx system.

 

[Thistledoo]

check your main connector going into the MCX box....make sure all pins are fully seated.

 

[robertyoke]

pressure check the whole system....cap the exhaust and intake add 15~20 lbs air listen for air leaks

 

[aart]

will be doing that next chance, sent controler away to reflash today. see what happens after i get it back i guess.