Engine Replacement

[Sword]

My 2002 2300 SR tops out at only 3800 RPM's. My mechanic thinks it probably has a bad cylinder. Not making any unusual noise but it should develop at least 4500 rpm's. Need to start thinking about a replacement long block.
Does anyone have advice as to where I can find a remanufactured RELIABLE long block or even a new long block?
The engine is a 5.7 250 hp Merc. 2bl. Alpha 1 gen II

[jparsons121]

I’ve used New Marine Engines, New Marine Engines 4.3L, New Marine Engines 5.7L, New Marines Engine 350, New Marine Engines 454 and More with good results.
However, I’d question your mechanic on what diagnosis he’s done to support replacing the block. Did he do at least a compression/leak down test or pull the head to rule out any other causes?
Dropping a cylinder would have an affect on reaching wot, but there can be many reasons that could be at fault, some as simple as a bad plug, wire, etc that are way cheaper to replace than an entire engine.

[mmwjr]

What does he mean by he thinks it's a bad cylinder? You need to find a new mechanic who knows/and will test to actually determine if the engine is bad. verify all cylinders are firing, compression test, leak down test, ...

Is this a new problem? Is the bottom clean? Verify you are not over proped.

[Sword]

Originally Posted by jparsons121

I’ve used New Marine Engines, New Marine Engines 4.3L, New Marine Engines 5.7L, New Marines Engine 350, New Marine Engines 454 and More with good results.
However, I’d question your mechanic on what diagnosis he’s done to support replacing the block. Did he do at least a compression/leak down test or pull the head to rule out any other causes?
Dropping a cylinder would have an affect on reaching wot, but there can be many reasons that could be at fault, some as simple as a bad plug, wire, etc that are way cheaper to replace than an entire engine.

Was just in the talking stage with my mechanic and what would be a worse case scenario. Prop is fine. Just bought the boat this year. Hour meter is suspect as it had 214 on the clock. Nineteen seasons and only 214? What was I thinking?
My fault for not checking it further
Anyhow next step is compression test

[Sword]

Originally Posted by mmwjr

What does he mean by he thinks it's a bad cylinder? You need to find a new mechanic who knows/and will test to actually determine if the engine is bad. verify all cylinders are firing, compression test, leak down test, ...

Is this a new problem? Is the bottom clean? Verify you are not over proped.

Yes he is going to check it out compression test etc. bottom not too dirty and prop is correct. If you are familiar with any marine engine dealers I would appreciate a recommendation. From reading these forums I know you have been around the block

[donald]

How do you know the prop is the correct one? did it ever max out at the correct RPM's.
If not I would check Mercruisers prop calculator.
Don

[Sword]

I’ll check Merc prop calculator.. first season with the boat.Never saw the tach go above 3800.

[mmwjr]

What prop size do you currently have and how many blades?

[Sword]

I’ll have to get back to you on that next week as I’m out of town. My old brain can’t remember the size

[shrew]

Originally Posted by Sword

My 2002 2300 SR tops out at only 3800 RPM's. My mechanic thinks it probably has a bad cylinder. Not making any unusual noise but it should develop at least 4500 rpm's. Need to start thinking about a replacement long block.

Replacement remanned engines, long blocks, short blocks, outdrives, etc. Try Michigan Motors.

I'm curious how you arrived at the determination that you need a repower. Top end ticking would be a valve. Low end clunking would most likely be a crankshaft or possibly a connecting rod. How did we jump straight to repower?

[Sword]

I forgot to mention that in the very beginning of the season I sent an oil sample to Blackstone labs and the results were not good. They said the analysis showed serious wear.
I haven’t determined yet weather this engine is going south on me but with the oil analysis and the low RPMs plus my bad luck I may be going in that direction. But I am waiting for my mechanic to do a compression test if you ever gets around to it

[Sword]

Originally Posted by jparsons121

I’ve used New Marine Engines, New Marine Engines 4.3L, New Marine Engines 5.7L, New Marines Engine 350, New Marine Engines 454 and More with good results.
However, I’d question your mechanic on what diagnosis he’s done to support replacing the block. Did he do at least a compression/leak down test or pull the head to rule out any other causes?
Dropping a cylinder would have an affect on reaching wot, but there can be many reasons that could be at fault, some as simple as a bad plug, wire, etc that are way cheaper to replace than an entire engine.

The other thing the troubles me about this motor is the oil report I sent to Blackstone labs back in April. Their analysis indicated severe engine wear.

[Sword]

Back in town and checked out the prop. It is a Mercury Marine Mirage plus.

Numbers on it: 48-13702 21P. 3 blade SS What do you think ?

[mmwjr]

I would think a 19” prop would be a better selection for your boat but it would only give you another ~200 rpm at WOT. Did the mechanic complete the compression test? That oil analysis probably showed bearing and ring wear so she may be down on power.

[Sword]

Don't think it's worth it to change the prop.
My mechanic won't be able to get to it 'till spring for the compression test. Too busy doing winterizations. We have a serious lack of repair facilities around here. He is just about the only game in town.
I'm going to send in another oil report tomorrow as instructed by Blackstone Lab. Holding my breath on that one.
If you know of any young upstart boat mechanics who want to relocate to Delaware County, Pa. area and make a fortune give them a buzz.
I really appreciate your input. I'll check back with you after the oil report. Again, thanks.

[Patrick Bodkin]

Many people from all over Eastern PA keep their boats down on the Sassafras River on Maryland's Northeastern shore where we are. About a half dozen fully staffed Marinas down here off just off of Route 213. Great access to both the Delaware River & the Chesapeake Bay via the C & D canal. You might want to consider it.

[Sword]

Yes that is a great area for boating. Some of the fearless types at my marina (on the Delaware River) travel the 2+ hours to Schafer's canal House. Been there many times....by car. Just too far to travel for me to get to that water.
That's a nice looking rig you have there. Sleep aboard ?

[Patrick Bodkin]

We have slept on the boat a couple times, but we only live 10 minutes from the Marina and our accommodations at home are much more comfortable. In the event that we took an overnight trip that is always an option.

[shrew]

Originally Posted by Sword

Some of the fearless types at my marina (on the Delaware River) travel the 2+ hours to Schafer's canal House. Been there many times....by car. Just too far to travel for me to get to that water.

Wow, 2 hours is nothing. We travel at 8 kts. It typically takes 3 hours to get anywhere good. As a result, we don't travel for day trips. When cruising, 6 hour days are common. We spent 28 days cruising a few years ago with many 6 hour days while my auto-pilot was broken. We had to hand steer the whole way.

[Patrick Bodkin]

By boat I can reach both Schafer's and the Chesapeake Inn in about an hour once I get up on plane (27 mph), or its 30 minutes by car.