2003 Sea Ray 260 Sundancer not reaching top speed

B

BennyC1960

Member
May 25, 2020
74
Boat Info
2003 26da sundancer
Engines
Merc Bravo III
Hi I have a 2003 Sea Ray Sundancer 260. I just purchased a boat two months ago and was topping out at about 30 mph cruising speed. Recently the boat now only goes up to about 25 mph and tops out at about 4000 RPM at full throttle. I had barnacles cleaned off the propeller but that hasn’t helped. Any thoughts on what might be causing the issue? Thanks
 
If you had barnacles on the prop... are they on the hull bottom, too? ANY growth - even just a slime layer - will greatly impact performance. You should be able to get at least 40MPH and 4,800RPM.
 
+1 on hull growth. Sorry for the obvious questions - what about your trim tabs and outdrive trim? How quickly is the boat coming up on plane?
 
Cap'n Scuba Steve said:
+1 on hull growth. Sorry for the obvious questions - what about your trim tabs and outdrive trim? How quickly is the boat coming up on plane?
Click to expand...
Thanks. Hull is clean and trim tabs/0utdrive in proper positions. Not sure how quickly it comes up on plane.
 
Ok, thanks - that at least eliminates those variables. Next thing I would try is to warm up the engine and advance the throttle only and see if you can get above 4000 RPM. I wouldn't leave it there, I would just see if you can achieve it and if it revs quickly. This is how I would start to determine if it was an engine issue or a drive issue.

Another thought is if you can get the drive out of the water, I'd pull the props and make sure there is no fishing line or anything else wrapped around the drive shaft.
 
You're 100% positive that the hull is perfectly clean?

As I mentioned above, you should be able to get at least 40MPH. You were originally only getting 30MPH - so even then something was wrong. You mentioned that the drive was "in the proper" position, which I assume you are referring to trim position. But, can you better explain how you used trim (specifically "up") to get your top speed? Again, 30MPH is still wrong so I'm wondering if you aren't trimming properly. If the hull and props are good, and you are trimming properly, then you're looking at tune-up items and/or engine problems. The idea here is to eliminate "free fixes", first.

One other "freebie" thing you can check is your fuel quality. Dump the filter into a clear glass jar (or siphon from the filter hole... as you may have a Cool Fuel 3 setup)

FYI, revving in neutral doesn't really tell us anything. There needs to be a load on the engine.
 
Lazy Daze said:
FYI, revving in neutral doesn't really tell us anything. There needs to be a load on the engine.
Click to expand...

For the most part, I agree 100%. Though revving in neutral would likely show a compression issue such as with a burnt/stuck valve, thus the detail about how quickly it revs. Though I'd really have to hear it or see it unless the OP knows engines well.

Even with full fuel and water, that hull should run 30 MPH at ~4k RPM and be nowhere near wide open throttle.
 
What Engine??
I have same boat with 350 MAG.
Top speed (GPS) is 39mph @ IIRC ~5400rpm

I cruise at 3700-3800 rpm at around 26.5-28mph depending on load/wind/trim, etc.
 
TimW said:
What Engine??
I have same boat with 350 MAG.
Top speed (GPS) is 39mph @ IIRC ~5400rpm

I cruise at 3700-3800 rpm at around 26.5-28mph depending on load/wind/trim, etc.
Click to expand...

5.0 230 HP
 
You must log in or register to reply here.

Forum statistics

Threads
113,118
Messages
1,426,472
Members
61,034
Latest member
Lukerney
Back
Top