"New" 1981 260 SRV: Boy is it SLOW!!! Advice please?

S

shay_mcquaid

New Member
Feb 27, 2010
3
Texas
Boat Info
1981 SRV 260
Engines
Mercruiser 228 =(
Thanks for looking.

I just bought a 1981 Sea Ray 260 SRV Sundancer.
Mercruiser 228. Title says 260 hp.
I was quite suprised at how slow it was.

14 mph on gps @ 3000 rpm
17 mph on gps @ 3300 rpm (wot)

I realize it's a heavy boat but jeez!

Should it be faster?
I know it had lower unit replaced.
So I don't know condition/size of prop yet. Water too cold.:grin:
Where should I start for the troubleshooting?

Thanks in advance for any input,
-Shay
 
what prop are you running? your gonna have to find out what prop is on the boat, 3300 at wot is not right I know that for a fact I would think the motor should turn a minmum of 4200 or so, 4600 to 4800 at wot is ideal.
 
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That is a lot of boat for that motor. But certainly you numbers are a bit low. A few things:

Bottom dirty...real dirty?

Hull waterlogged?

Prop hub spun?

Engine coupler bad?

Anchor deployed?...just kidding.
 
You definitely have an issue - WOT for that engine should be between 4200 and 4600 RPMs. Your tach may be off so you may want to verify with an external if possible. Matt is on the right track - the wrong prop can drastically change the performance and your WOT.
 
Slow down and don't start any troubleshooting until you find out all the details.

Like Matt suggested, the prop. Also what gear ratio is the drive (especially since it was replaced)? What do you know about the replacement? Find out.

Also, what's the condition of the boat bottom?

Are you trimming up?

WOT should be somewhere around 4500.


EDIT: Looks like I'm the slowest typer!
 
Don't forget to look at that carb and visually confirm WOT and in fact the secondary's are indeed opening. It's not all that uncommon to actually feel a little stumble as the come in.
 
yes, the 228 is a dog. but your results are just wrong.

do the previous check-lists already mentioned. then check plugs/wires/points/cond./ignition. (they may need replacement as well).

good luck.
 
Engine Won't Reach Operating RPM (WOT). Check....

1. Fuel condition. Type and Octane possibly old fuel
2. Propeller pitch or diameter, damaged blades
3. Restricted fuel pickup tube or anti siphon valve Fuel System Test
4. Crankcase oil volume, high oil level can cause aerated oil and lifter collapse
5. Marine growth on hull and outdrive
6. Wrong gear ratio in outdrive
7. Restricted carburetor air intake (clogged flame arrestor)
8. Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive
9. Poor cylinder compression Compression Test
10. Carburetor defective, or wrong type.
11. Fuel pump pressure and vacuum
12. Boat overloaded, improperly loaded, or improperly trimmed.
13. Engine Overheating
14. Engine timing and ignition system operation
15. Remote control cables and linkage for proper travel to open throttle plates fully.
 
I had the same experience with my old 89 268 Sundancer with 454/bravoI. Just thought it was the way this bigger boat handled... then... while taking my Father In Law (of course) out with us on the boat the max rpms dropped even lower. I didn't let on and nursed it off plane back to the dock.

Upon closer inspection of the engine, I noticed a spark plug wire hanging down. It had come off the plug. So I decided to check the others. There was a 2nd wire hanging down on the other side of the engine! Popped it back on too.

Fired it up and MAN WHAT A DIFFERENT BOAT!! Turn a V8 into a V7 and you may not really notice it running that roughly at idle, but turn it into a V6 and then it becomes obvious! Replaced the wires and never had another issue.

Maybe too simple, but check your wires!:grin:
 
My money is on the following:
1. Wrong prop, too much pitch or wrong dia.(maybe both) Sounds overpitched to me.
2. Give the boat a full tune up including timing and compression checks
3. Be sure carb is functioning.
4. Check the gear ratio in the OD. Perhaps a PO has swapped a drive from a 4 or 6 cyl engine.
Let us know what you find.
 
shay_mcquaid said:
Thanks for looking.
I just bought a 1981 Sea Ray 260 SRV Sundancer.
Mercruiser 228. Title says 260 hp.
-Shay
Click to expand...

What do you have here? The older Mercruiser's posted HP ratings on the engine. Do you have a 228 hp 5.0 Liter (305ci) 4 bl?

Could the title have more hp than the engine?

330hp will push a 268 40mph.... 260hp will push a 268 35 mph. (needs hp at 3000 rpms to get up on plane)... Just a guess here, but at WOT 17 mph. 3300 rpm's your not even out of the water yet. Once you are, the boat frees up and the rpm's will come up too.

Were all assuming here you know how to trim the boat to get it up and then trim it out for speed!

Let us know what’s going on here.
 
I just sold mine. After a new carb, prop change, power trim pump, WOT was about 4400 properly trimmed out. weight inside the boat and the position of the weight it would move. Trim the out drive up and using the trim tabs to get as much of the boat out of the water as you can could does make the difference. And Bonbini is correct about 3000 just to get out of the water. I would cruise about 3500 rpm.
 
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Wow.
I really appreciate you guys' input!

Had to work this weekend so plans on visiting the marina are postponed till next week.
Too bad too,perfect weather.

I'll investigate more fully next weekend.

Thanks again.

What was the original prop pitch/dia.?
 
shay_mcquaid said:
Wow.
I really appreciate you guys' input!

Had to work this weekend so plans on visiting the marina are postponed till next week.
Too bad too,perfect weather.

I'll investigate more fully next weekend.

Thanks again.

What was the original prop pitch/dia.?
Click to expand...

Shoot an email to searay
they'll give you the exact specs on how that power/drivetrain was shipped.
 
You can also try a local prop shop and ask them what you should be running. I had a similar problem when I first got my 1979 260 DA. I maxed out around 3200 rpms and was a total pig with more than 2 people onboard. After doing a little clam digging with my prop it began to cavitate. What? There are alot of shoals in this area.:huh: Anyway, went to Bossler & Swezey , local prop guys, to recond the prop and told them what I was running it on. They informed me that I was over pitched and over diameter. Oh and by the way, the prop I brought in was toast!! Got the new recommended prop and it was a totally different boat!! :grin: Todd
 
Ok,
I had a short weekend out on the boat...

Come to find out the outdrive is full down and unresponsive.

I was told by previous owner (PO) that it worked.
I thought the guage was inoperable:smt009

Seems like I can get some more RPM out of Her when the trim issue is sorted. Is that probably true?

Thanks...
 
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