400ex dead spot in throttle

[nxkustoms]

My 400ex has a 11 to 1 416mm piston, stage 2 cam, head work and some other little tweeking. When i let it sit at an idle then i pin the throttle it will usually die, and then at top end it will cut out a little (not rev box) more like a pop here and there, but you can really feel it.

[NacsMXer]

Sounds like it's rich on the main jet if it's cutting out at WOT.

[nxkustoms]

Ya i am going to go all the way through my carb, my plug reads brown. Also needle and pilot jet are stock, main jet is a 175 and cant remember how much i raised the needle.

[bigredisb]

I had the same exact issue on my machine all though its almost stock. I put a home made shim under the needle and have never looked back.

[NacsMXer]

Originally posted by nxkustoms
Ya i am going to go all the way through my carb, my plug reads brown. Also needle and pilot jet are stock, main jet is a 175 and cant remember how much i raised the needle.

Yeah 175 is a bit on the fat side for your mods I would say. I'd lower the main jet to start off, then play with the needle settings if it doesn't clear it up all the way.

[drew416ex]

I had a similar setup on my engine running a 42 pilot, and a 160 main.