1800 rpms is max

[Boatman23]

I've recently came across a 2000 searay sundancer with twin 305's and bravo two outdrives. The boat sat for a few years before I got it. The engines only had 423 hrs on them. No when I put it in neutral and Rev up the engines they will climb to 4000+ rpm's. Now when I get out to the open river and slowly give it throttle it will climb to around 1800 rpm's and any thing after that as far as throttle does nothing. At full throttle I'm around 1800rpms on both engines. New gas, New oiland filters, New wires and plugs. But all this doesn't change anything. New to the searays and sure would appreciate any inside onthis.
Also It feels weird running because it feels like vibrating like the prop is bent or something. Engines just don't run and feel smooth. They vibrate the entire boat.

 

[Golfman25]

Start with the easy stuff. Check the props. Make sure they are at least close to stock specs. Make sure fuel system is clear, new fuel filters? Compression check on the engines.

 

[Stray Current]

Check your compression, spark and fuel pressure to start. Thowe are TBI I believe, how does the fuel spray pattern look?

 

[Lazy Daze]

FYI, throttling up in neutral does nothing as far as diagnosis goes. It's basically a moot point kind of thing.

What pre-purchase checks did you do? List those for us.

Dump each of your fuel water separators into a separate, clear jar - observe - let it set for an hour and observe again. Post pics.

 

[hughespat57]

“Boat sat for a few years”
Is the gas that old?

 

[Jeff Delbuono]

I had the same issue when i git my boat. Changed every part possible. What it ended up finally being was the timing. Check that all the wires are in the correct order and then set timing. Dont throw money into parts just yet

 

[Skybolt]

Start with the easy stuff. Check the props. Make sure they are at least close to stock specs. Make sure fuel system is clear, new fuel filters? Compression check on the engines.

+1 especially the compression test.

 

[Scott215]

Yeah absolutely on the compression test You could always look at to a scanner to see if anything's wrong with it and I was told never to rev my boat up in neutral to over say 1500 RPMs with no load on it it's not good I was told

 

[techmitch]

Yeah absolutely on the compression test You could always look at to a scanner to see if anything's wrong with it and I was told never to rev my boat up in neutral to over say 1500 RPMs with no load on it it's not good I was told

Huh?

 

[Skybolt]

Yeah absolutely on the compression test You could always look at to a scanner to see if anything's wrong with it and I was told never to rev my boat up in neutral to over say 1500 RPMs with no load on it it's not good I was told

There should be no issue with 3K or so. Even red line briefly with a gas engine, just make sure it's warmed up. Never on a cold engine.

 

[Scott215]

Was just told never without a load. All good bro

 

[Jeff Delbuono]

It has a rev limiter. Its ok to pump the gas to clean out the cylinders. But like said. Never on a cold start

 

[Scott215]

It's all good maybe that was on muffs, I don't remember, honestly

 

[Lazy Daze]

It's totally fine to goose the engine, even on muffs. What you don't want to do is run the RPM's too high on a hose for an extended period of time. There's not enough water flow and too many inconsistencies from one hose to another (GPM). Watch your temps.

 

[Bruceflinch]

How clean is the hull? Maybe Barnacle Bill built a neighborhood on the bottom?