So, here's the story which seems a bit strange. In summary:
Tach suddenly reading high. (by about 1500 rpms).
More detail: boat is 2007 Catalina 309. Engine is 3ym20. 620 hours on it. We've had the boat for about 18 months and up until now the tach was rock steady. A couple weeks ago, I started the engine to head in after sailing and the tach (while engine idling) pegged all the way up...then all the way down a couple times then settled down. A week or so later I changed the impeller (yearly maint) and after finishing, started it up to check for leaks. Tach swinging way up then way down. I realized that this time I had the battery charger on at the same time as the engine, and figured that might be a problem. Shut down the battery charger and tach settled down.
However, now every time I take it out it is reading high at least 1000 rpms, more like 1500. The engine is running fine and steady. It's just reading high. When I push the throttle lever to full cruise (based on feel and sound and speed of boat), the tach reads 4000!
I plan to try adjusting the tach to match a hand held I have...but just wondering if anyone has any thoughts.
Thanks much, Dave - Tampa, FL
Tach suddenly reading high. (by about 1500 rpms).
More detail: boat is 2007 Catalina 309. Engine is 3ym20. 620 hours on it. We've had the boat for about 18 months and up until now the tach was rock steady. A couple weeks ago, I started the engine to head in after sailing and the tach (while engine idling) pegged all the way up...then all the way down a couple times then settled down. A week or so later I changed the impeller (yearly maint) and after finishing, started it up to check for leaks. Tach swinging way up then way down. I realized that this time I had the battery charger on at the same time as the engine, and figured that might be a problem. Shut down the battery charger and tach settled down.
However, now every time I take it out it is reading high at least 1000 rpms, more like 1500. The engine is running fine and steady. It's just reading high. When I push the throttle lever to full cruise (based on feel and sound and speed of boat), the tach reads 4000!
I plan to try adjusting the tach to match a hand held I have...but just wondering if anyone has any thoughts.
Thanks much, Dave - Tampa, FL