I have had my 1984 MK1 for about 6 months and it has always run at 2000 rpm max in gear. I hit 6.5 mph towing dinghy at 2000 rpm. Neutral would go higher but I never ran it all the way up to see how high. I went through the fuel system and changed fuel filters although they looked brand new. Verified pickup in fuel tank and also filter in lift pump. The motor ran and started flawlessly and never smoked. For this reason I concentrated on fuel flow.
I decided to adjust the governor. I ended up turning it CCW 2 complete turns. I took a test run pulling dinghy with a dirty bottom(freshwater) and got to 2400 rpms and started seeing a small amount of black smoke. I now feel that I have adequate fuel flow. I will dive the prop next and see what size it is. It is a 2 blade so I suspect it may be original.
I wonder if a previous owner changed the governor? The cover over the nuts had gold paint all over it. It is pretty chewed up now where I took it off with pliers.
I found lots of posts on low RPM but most of them never posted the solution.
Comments welcome.
Catalina 36 MK1
1984 Hull #306
Mike
Have you checked your RPM's with a timeing light? 6.5 knots towing a dink sounds pretty good at 2000 RPM's with your three cylinder motor which inclines me to think your RPM meter is not showing the actual RPM's that you are turning.
__/)__/)__/)__Capt Mike__/)__/)__/)__
Punta Gorda Florida
1990 Std WK M35 Hull #1050
I have not verified the tach. That is a good idea. The rpm in neutral was going way higher than rpm in gear so I did not focus on the tach. I was making 6 or 6.5 mph rather than knots but it may still be on the fast side.
Does the dinghy make much difference? I have a 10 foot rigid bottom avon.
Catalina 36 MK1
1984 Hull #306
Took a test run with GPS (no current or wind) with 10 foot avon RIB dinghy towed behind. I was able to reach 7.0 knots with just a little black smoke starting. The tach shows 2400 RPM but I need to verify it.
Catalina 36 MK1
1984 Hull #306
I found an optical tachometer at Harbor Freight Tools for about $30. I would think you should get 3000 or better. Isn't the engine rated for about 3200?
And I agree that if you're getting up to 7 knts with no tidal help, you must be doing more than 2000.
I've had problems with my tach going weird from time to time. Pulling the instrument panel and getting to the back of the tach, then turning the adjustment screw back and forth a few times always fixes it. Cleans off the contacts which I understand are not very robust.
Sam
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida