Problem

[TBSK]

Everyone is out riding but I thought I would try. 08 Nytro MTX MCXpress idels horrible. Sounds like I have a exhaust leak, but everything checks out okay with exhaust. Pulled the tank, ran the sled so I could maybe see or hear something different. All I can notice is that the center pipe while running only get half as hot as the two outside ones. I have lots of spark, lots of compression, changed plugs, replaced stock injector, checked for leaks ect. I did notice when I pull the plug that supplies the power to the middle injector, the exhaust leak (tick) goes away. That is why I swaped an injector, it did not help. What else can I try?

 

[0007]

If it's ever been overboosted/detonation it can eat the head shim, it will idle but badly and it could make a snapping noise as combusion leak's from cyl to cyl
Leak down test would answer any engine question

 

[Hrt Offroad]

Everyone is out riding but I thought I would try. 08 Nytro MTX MCXpress idels horrible. Sounds like I have a exhaust leak, but everything checks out okay with exhaust. Pulled the tank, ran the sled so I could maybe see or hear something different. All I can notice is that the center pipe while running only get half as hot as the two outside ones. I have lots of spark, lots of compression, changed plugs, replaced stock injector, checked for leaks ect. I did notice when I pull the plug that supplies the power to the middle injector, the exhaust leak (tick) goes away. That is why I swaped an injector, it did not help. What else can I try?

I worked on an MCX Nytro a while back that had a terrible idle problem...it would only idle at 400-700 rpm. It ended up being the control box!

 

[TBSK]

Found problem, stuck valve on middle cylinder. No clearance at any position, Engine is coming out.
Now that I am pulling engine, any recomendations on add ons, mods, I should be doing now while its easy to do.
Did compression and leak down, all is good.
08 Nytro MTX MCX, head shim, 16 lbs, c111 / 92 50/50.