2008 Grizzly 450. Starts and idles fine but at about 10 mph why does it start to cut out like a rev limiter?

The Rhino was released in 2004 and was offered with a 450cc or 660cc engine with a carbureted fuel system. The 450cc engine was based on the Kodiak 450 ATV engine architecture, and the 660cc engine was based on the Grizzly 660 ATV engine architecture. Both engines were modified for use in the larger Rhino chassis. In 2008 Yamaha upgraded the big bore Rhino to the 700cc fuel injected engine that was again borrowed from the Grizzly 700 ATV. Yamaha did not offer the 450cc engine size from 2011 to 2013. All engine configurations were single cylinder four-cycle designs, mated to Yamaha's Ultramatic transmissions. All Rhinos use an electronic speed limiter system to restrict the top speed of the machines to approximately 38 MPH (61 KPH So the answer is no, oil is added to 2 cycle engines.

either the float height is wrong, the main jet needle needs lifted or there's an air leak somewhere.

sounds like your reverse sensor is bad and the cdi limits rpms while in reverse as a safety thing.

possible that the fuel tank is not venting properly

sounds like you are hitting the rev limiter. If it launches that hard im guessing you have a belt or clutch issue.

Have you checked your belt condition? I have a grizzly 700 & it cut down to 10mph max and sputtered when my belt shredded in the housing. I think it does this to maintain what belt is left and to keep from damaging parts. I never had the blinking light that I can recall though. just a thought.

If it was a fuel shortage the engine would rev but to limited speed. This is a lack of air to throttle body. Check for clogged air filter and all the piping and the throttle body.

well i would have the catalic converter checked if it's clogged it would cause this.

what engine is installed on your car? my initial impression is the ignition igniter module.

Well there is a rev limiter built into the pcm on your car. It is much lower rpm's in park and neutral. When u hit the rev limit of a particular gear selection, the pcm starts cutting out the injectors(fuel). This is normal. As far as the jerky feeling, the only thing I know of is a service bulletin that may apply to your car. It involves a revised torque converter for the transmission. It would only apply if your feeling this at speeds of approx 35 mph or higher when the torque converter lockup engages after a shift. Ask your dealer about a possible tsb for this if you think this may sound like your problem or search for tsb's(technical service bulletin's) yourself on the internet.