Hi everyone, I have a 2015 UFORCE 800 that I did a rebuild on. Engine is back in and it starts the first try. howver i notice the front exhaust pipe glows red after about 30-50 seconds. the rear exhaust pipe is ok. I checked the coolant and it seems fine, even pulled the theromast and going without one to make sure the engine is getting good coolant, both coolant lines get warm so that tells me coolant is flwoing through the engine AND iI get a nice swirl of the coolant at the rad fill tube. Can it be a timing issue as I had someone tell me to be careful with timing as it can be tricky. Thought it might be that it is running lean, but i do have the filter air box in place. when I pulled the plugs, they are OK and not fouled. Anyone have any thoughts or had this issues.

TIA

Craig

[2015 Z Force 800 53/Trail EPS]

Exhaust pipes glow a little naturally when warmed up and under power. They also glow when the fuel charge is very lean, very rich or when there is a leaking exhaust valve allowing the detonation to blast through. Because you say this is happening very quickly I tend to think there is a leaking exhaust valve. Put it on TDC of the compression stroke and lock the crank. Use the lock bolt or because it probably has a wet clutch being a 15, put a breaker-bar with socket on the fan retainer bolt and wire it down. Pull the plug and rig air to the cylinder and regulate it to something under 60psi. Put your ear to the muffler and see if you hear it leaking. Do check the lash...it may just be set to tight.