2GM RPM can't go above 2500 -- FIXED IT

[Eric Steege]

I have seen several posting from other H31 owners about why they could not get 3600 RPM in neutral, and I was experiencing the same thing. I have never been able to get more than 2500 rpm. I was dreading having to replace the exhaust elbow, but there was one other idea that I saw that I tried this weekend. Here is the article I found in the archive:"After trying all the usual ways to fix my low rpm 2gm yanmar (replaced fuel filter, cleaned the mixing elbow, adjusted the cable at the engin )I still was only getting 2500 rpms in neutral. As a last ditch effort I pulled the compass to get a look at the cable where it connects to the fuel lever and there it was!!! The benical the compass mounts has a notch for the linkage to pass, but it was turned so it blocked the lever from full speed. I removed the four screws, aligned the notch and presto 3500 RPMS ! Don't know if this mistake was factory or from some genius who owned the boat before me who still to this day can't figure out how replacing the compass robbed the boat of 1000 RPMs. Just FYI. S/V Lady Di II"When, I took my compass off, and sure enough, the pedistal had been assembled incorrectly so that the throttle was blocked at about 2/3 the open position! There is a notch in the pedistal segment right above the throttle that needs to be aligned right above throttle linkage. Mine was 180 degrees off. I rotated and reinstalled and now the throttle CAN bring the governer to the full throttle position as specified in the Yanmar manual. I am dry docked until Thursday, so I don't KNOW that I fixed the problem, but I am pretty darn sure that this will get me from a max of 2500 rpm to 3600 rpm and HULL SPEED for the first time under power! I will let you know if it shakes out!Regards,Eric SteegePerfect Union, 1984 H31Bayport, MN

 

[Steve Dion]

Only one person to blame!

Eric:The only person to blame is the one that put the mounting plate on the boat (not Hunter). They did not come with them. It was the easiest thing to do (but caused the problem). The plate is suppose to be on top of the pedestal and below the control levers.

 

[Eric Steege]

It worked -- 3500 RPM's last night

It worked -- I am able to get boat speed. I do get a little smoke at 3000 and above, so I need to watch that.Eric SteegePerfect Union

 

[Brett Beach]

Mine Too

Eric, I am the new owner of Cabaret, the other Hunter 31 in Bayport and I though I would check the throttle before launch. The same mis-alignment was true on our boat as well, so rotated it and now it lines up. But, my throttle does not move far enough to hit the notch, anyway. It is being limited at the engine. I do not know if I have an RPM issue since I have not launched yet, but I did note that the throttle tends to want to slide back down on it's own. There is probably an adjustment to control the friction that hold it.Anyway we had a nice barbeque in the cockpit, on the trailer, in the parking lot. Sure hope the river goes down soon so I can move the boat from Bayport to Lake City.

 

[Eric Steege]

Be careful not to bend the throttle cable

Brett, check the movement at the engine. According to the Yanmar manual, the full throttle position is 5% short of vertical. You should be able to move the throttle to that position by hand at the engine. This will tell you if you have full motion. My cable was bent at the pedistal, probably caused by over pressure to move it to full throttle. The adjustment screw is bent, so that I can not adjust it at the pedistal. Not too big of a deal, but something to be avoided.Caberet is certainly a beautiful boat, and it is sad to see her leave Bayport.Are you motoring down to Lake City or trailering?Regards,Eric SteegePerfect Unioneric.steege@apexit.com