Revs go to max at WOT in reverse and neutral, not forward

[Cthoops]

Brand new Beta 16 with ten hours on it. We decided to take the boat out for the first time in about five months and discovered the RPM's won't get to 3,500 at wide open throttle. It gets to about 3,000. We hit 3,500 in reverse and in neutral. This has all been tried while tied to the dock.

We had a catastrophic premature failure of our previous Beta and replaced like for like. We got 3,500 rpm at WOT with the last Beta. Exact same engine, didn't change the propeller, so it shouldn't be a propeller pitch issue. We had a diver clean the prop and gained 500 rpm (was getting 2,500 rpm, now 3,000).

The injectors are brand new. The throttle cable looks to be adjusted properly. We're going to change the fuel filters next in the off chance they picked up some crud during the ten hours we've used it. Any other suggestions if the fuel filters don't work?

[rslifkin]

Not reaching rated RPM with the boat at 0 speed isn't necessarily abnormal, as the prop is loaded more with no forward speed. Take the boat out and run it up to WOT with the boat moving, then see if you're still short on RPM. If you are, there's an issue somewhere. If not then you're probably fine.

Props usually have less grip on the water in reverse (and some transmissions have more gear reduction in reverse), so higher RPM tied to the dock in reverse doesn't surprise me.

[Statistical]

This has all been tried while tied to the dock.

So you haven't tried in open water while moving? If you haven't I would try that. If you can get hull speed at max rpm you are good. A static pull (engine pulling against lines) will usually be lower rpms.

[sailorboy1]

engine load in forward is more than reverse

when you parked the boat would it do 3500 in forward?

[Cthoops]

Originally Posted by Statistical

So you haven't tried in open water while moving? If you haven't I would try that. If you can get hull speed at max rpm you are good. A static pull (engine pulling against lines) will usually be lower rpms.

No, we haven't tried it while moving since we had the prop cleaned yesterday. We'll try it away from the dock.

[Cthoops]

Originally Posted by sailorboy1

engine load in forward is more than reverse

when you parked the boat would it do 3500 in forward?

No, the boat is at 3,000 now in forward when tied to the dock. It was at 2,500 before the prop was cleaned, and that was in open water and tied to the dock.

[Statistical]

Originally Posted by Cthoops

No, we haven't tried it while moving since we had the prop cleaned yesterday. We'll try it away from the dock.

Then be sure to give us an update. Fairly certain it will perform as expected while underway. If you were only getting something like 1000 rpm max in a static pull that would be bad but a little less is common.

[Cthoops]

Originally Posted by Statistical

Then be sure to give us an update. Fairly certain it will perform as expected while underway. If you were only getting something like 1000 rpm max in a static pull that would be bad but a little less is common.

We're going to take it out after I get off work today. I'll definitely report back.