North River 4.3 Vortex/Kodiak Situation

[nikkidog]

I have an 03 NR Trapper with a 4.3 Chev Kodiak and two stage Kodiak pump (about 60 total hours). We were fishing the CR below Bonni yesterday (which by the way was horrible with the wind). Went to pull my anchor, looked down at my tach and it was reading 6000 rpm coming out of the hole. After having a mild coronary I immediatley backed the throttle down and watched the tach bouce around erratically for a bit. The engine sounded normal as always and not over rev'd. The thing has a tendency of running in the the upper 4000's on a hole shot hammer down. Was wondering what your thoughts were.......bad tach, bad sender, worn impellers (however, the boat has plenty of speed and power). I'm very concerned. The boat has been flawless since I bought it about two years ago with less than 30 hours on it. Also, the guys at KEM told me you can't over rev their engines with the electronics on them. Why did the tach show 6000 ?? Also, if the rpm's were that high wouldn't a rev limiter kick in. Any help would be appreciated.:confused::confused:

[BIGCSS]

Check the connections where the tach hooks in at the instrument panel and then also back at the engine where it hooks in. Connections will get a little bit corroded and it will do that. Alot of the time when it reads really high just tap on the face of the tach and it will go back to normal. My Koffler tach started doing that this past winter and that solved it. The boat is 5 years old. Anyhow I hope this helps some.

[backlash442]

I have a 4.3L in my Seahawk. Sometimes (not very often) the tach will read higher than normal. A whack or two with my knuckle knocks it back down to normal. I know it's the tach because the engine sounds normal. I've never had it read 6000 rpms though. Usually it's around 2000 rpm or so when it should be at idle.

[WaterDog]

:yeahthat:

Also I think most of the electronic engines have rev limiters to help protect against over reving for whatever reason.

[namu mac]

Look at the back of the tach. Is there a switch that changes it from 4 to 6 to 8 cyl or outboard? If so there probably is a slotted do hickey that you can change the function with. Take a scrwedriver and move this do hickey back and forth between the settings several times and then set to proper position. Sometimes corrison will build up on these contacts and cause errronious readings.

[nikkidog]

Thanks for your help guys. This thing has been pretty heavy on my mind today. I'll be in the boat tomorrow afternoon checking things out. Nik