Timberwolf 150DHB engine cutting out.

[larryno1]

Hi all I’m having trouble with my Timberwolf chipper it’s a 2007 model , it starts and runs on low revs ( photo with green light ) as soon as you get past half revs it stalls and red light comes up in black box . I’ve changed both fuel filters and air filter is clean , fuel is getting around the system. I’ve also changed relay on black box and checked all wires to engine etc which appear fine . Any help / ideas would be very much appreciated!! 
Many Thanks 

[htb]

All the bits you have done , with relay etc are for stress control.

Kubota engine are pretty basic, its probably to do with the ignition switch they are known to fail. How clean is fuel tank, could be water in fuel or crud floating around blocking the pick up pipe. 

[larryno1]

Ok thanks for the reply I haven’t actually checked fuel tank , which do tomorrow , with the ignition switch is there a way of testing? Thanks 

[woody paul]

When it stops is it slow or sudden,  

[larryno1]

It happens suddenly 

[woody paul]

22 minutes ago, larryno1 said:

It happens suddenly 

Would of thought electric fault, will moving throttle hold key to stop it vibrating and moving. 

My 150 would shut down when you dropped rev down turn out to be ignition switch, just sprayed WD40 into key hole and have never had a problem with it,