Falling short of max engine RPMs

[cwyckham]

I'm sure somebody has already suggested checking the set screw on the throttle lever on the side of the engine?

[Cheechako]

Did you find where all the water in the filter was coming from?

[Terra Nova]

Bottom of the tank.

[blinkerfluid]

I've checked the throttle stop before, in fact it was one of the first things I looked at, but I'm going to check it again just to be sure.

I'm not sure how the water is getting in the tank, I'm not even sure if that's still a problem. The filter was full of water when we got the boat (I thought the filter was just empty at the time). I switched to the other filter for a little while before we changed them both out and didn't notice any more water accumulation. I'll definitely be keeping an eye on it though, don't want to have to have the injectors rebuilt again.

[Cadence]

Originally Posted by blinkerfluid

Haha yea, I read them all, be silly to ask for advice and then ignore it

I'll get it figured out and then let everyone know what the problem ended up being.

thanks again!

It sounds as if you have taken one of the soundest approaches I have heard. Valve clearances, injectors, etc. Since you have found more than one top end, are you sure yours isn't correct. Maybe you are chasing a ghost, and they just didn't publish your particular mfg. run? If it works for you, I'm not sure I'd worry about it. run it at 2400rpm.

Best of luck.

[SkiprJohn]

If your engine runs to 2400 and doesn't overheat I'd leave it at that. I know tinkering until you think it is perfect is fun but it seems you've found some issues that needed fixing already and now it's time to enjoy the ride. Different engines have different throttle stop configurations so maybe just a minor adjustment there at the governor housing will get you up to whatever speed you want to go.

[blinkerfluid]

Originally Posted by Cadence

It sounds as if you have taken one of the soundest approaches I have heard. Valve clearances, injectors, etc. Since you have found more than one top end, are you sure yours isn't correct. Maybe you are chasing a ghost, and they just didn't publish your particular mfg. run? If it works for you, I'm not sure I'd worry about it. run it at 2400rpm.

Best of luck.

Well thank you for the nice compliment. I suppose I can't be 100% sure that 2700 isn't correct if it's possible that they produced a run of engines that were rated differently than everything else. Still, 3k seems reasonable to me and I'm close to that already, so I tend to think that 3k is where it's supposed to be. I still need to take it out for a run under load and see what the RPMS are. My hope is that with the work we've done, she'll come up to 2700 under load now, we'll see.

[blinkerfluid]

Originally Posted by SkiprJohn

If your engine runs to 2400 and doesn't overheat I'd leave it at that. I know tinkering until you think it is perfect is fun but it seems you've found some issues that needed fixing already and now it's time to enjoy the ride. Different engines have different throttle stop configurations so maybe just a minor adjustment there at the governor housing will get you up to whatever speed you want to go.

I'm fairly happy with how it's running now, so I probably will fix other more pressing things, like the fact that the low pressure/high temp alarm isn't working. I'm hoping now that it's just an adjustment thing and there's not another problem that's keeping the rpms down. I'll run it like it is now and see what improvements, if any, there are.

[SkiprJohn]

Originally Posted by blinkerfluid

I'm fairly happy with how it's running now, so I probably will fix other more pressing things, like the fact that the low pressure/high temp alarm isn't working. I'm hoping now that it's just an adjustment thing and there's not another problem that's keeping the rpms down. I'll run it like it is now and see what improvements, if any, there are.

That's great! Those temperature alarms are pretty good to have if you can keep them working right. Usually ground wires or old corroded wiring is the culprit.

[Cadence]

Originally Posted by blinkerfluid

Well thank you for the nice compliment. I suppose I can't be 100% sure that 2700 isn't correct if it's possible that they produced a run of engines that were rated differently than everything else. Still, 3k seems reasonable to me and I'm close to that already, so I tend to think that 3k is where it's supposed to be. I still need to take it out for a run under load and see what the RPMS are. My hope is that with the work we've done, she'll come up to 2700 under load now, we'll see.

Just keep in mind, pushing a boat is like driving a truck up hill all the time.

Pushing harder is going to cause more wear. 2700 or 3000, 2400 sounds good as an RPM. 2200 running sounds better. What's the rush. If in one don't have sails.

[blinkerfluid]

Yea, hopefully the alarm is an easy fix, just need to get in there and trace all the wiring out.

I definitely don't want to run the engine at 3k rpms all the time, and understand the speed return for higher loads is minimal in comparison to the extra fuel burn. However, I also think being able to reach the engines maximum rated rpms is a good sign that everything is operating properly in the engine and the boat is propped correctly for maximum efficiency. To me, since I can't get max RPMS, then something must be wrong. I know now the valves were way out of spec and the injectors had water damage, so now hopefully the only thing "wrong" is that the governor has been turned down for some reason (or some other similar adjustment).

[Cadence]

Originally Posted by blinkerfluid

Yea, hopefully the alarm is an easy fix, just need to get in there and trace all the wiring out.

I definitely don't want to run the engine at 3k rpms all the time, and understand the speed return for higher loads is minimal in comparison to the extra fuel burn. However, I also think being able to reach the engines maximum rated rpms is a good sign that everything is operating properly in the engine and the boat is propped correctly for maximum efficiency. To me, since I can't get max RPMS, then something must be wrong. I know now the valves were way out of spec and the injectors had water damage, so now hopefully the only thing "wrong" is that the governor has been turned down for some reason (or some other similar adjustment).

I hope so. I believe you had previously said in neutral so you took over prop out of the mix. Yep, the return on speed/fuel, goes down especially once hull speed is achieved. Again best of luck.