DT200 rev limiter

I have a 1989 or possibly a 1988 Suzuki DT200. It has been a great motor for many years and today I had a strange problem. Two problems maybe. I don't know if they are related.

First the starboard side water temp light came on and the alarm was also sounding periodically. The port side was fine. Also the pee- stream was good, looked strong and wasn't putting out hot water. Touching the water jackets and it didn't seem hotter than normal and there wasn't a difference in temp between the port and starboard sides. Sometimes I figure stuff gets stuck and so I ran it up a bit to try and get anything stuck pushed through. This is when I encountered the second problem.

At idle it seemed fine, but once I tried to get up on plane the rev limiter kicked in. I've never experienced the rev limiter but I assume that is what I experienced. It seemed like it was intentionally misfiring, which sounds like the rev limiter. It took me a minute to look at the tach, but the rpm's were way too high. The engine didn't sound like it was that high, but obviously the tach thought there was a problem and so the rev limiter kicked in.

I have never spun a prop so I don't know what that looks like, but that was the first thing I thought of. After I pulled the boat out, I engaged the motor and tried to manually turn the prop, thinking it would spin if I had spun the prop. I couldn't get it spin, so I don't know if that was it or not. Can a spun prop still feel firm?

i am wide open to ideas.

chris

I have an update. Hopefully I get attention here versus starting a new thread.

I removed the the oil tank and went through the oil lines and the oil flow sensor. Cleaned out the screen. And now the water temp / flow sensor alarm is off. So that's good. But the rpm is still a problem.

i marked the hub and prop and ran it with the same result and the marks on the hubs were all still lined up, so I think my problem isn't a spun hub or prop.

the tachometer is reading rpm much higher than usual. Previously when the motor was running normally Wot is about 4200 and the motor sounds normally stressed at that rpm. Now the motor doesn't sound stressed or as loud as previous but rpm is very high on the tach, and the rev limiter is activating.

im at a loss on this one.

chris