Not getting RPM at WOT

[Henry]

 Hi everyone. Here are some details:

6BT 210’s pushing a 33 foot Riviera

Props freshly tuned by wilmington

2800 hours

well maintained and not abused.

I can easily get 2700 RPM ++ in neutral at the dock with no smoke. Underway I make 2400 and 2500 (Port/Star) with no smoke. Racors are fresh and clean.

 

Am I overpropped or am I overlooking the obvious?

 

Thanks all.

Topic

[Henry]

Hi All- Here is the update on my low power situation. Tony you were right, I was over propped.

Wilmington took out 2 inches of pitch and I can now make 2600 on both sides. I was slightly disappointed as I instructed that I needed to make 2700 at WOT.

Engines are running well and I picked up a little speed but I’m certain the 6BT’s 210 aren’t working as hard and that’s what I care most about.

When I haul the boat for bottom paint I will pull props again and take more pitch out to make 2700-2750.

Thanks for hanging in with me guys. Tony thanks for all your help. You’re a Cummins stud!

Henry

[Henry]

Thanks to all that have contributed to this string. You are all awesome..

I am getting the props tuned so that I can get 2700 at WOT…Should have them back on the boat by Friday and will give you all a full report.

Tony you’re right all along…I’m over propped and in denial. I don’t want to live in denial any longer.

[Philip]

Henry –

You posted the balance reports not the pitch reports.

If that’s all you got from Wilmington you need to call them again and get them to send you the before and after pitch report info.

Phil

[Henry]

PROP-REPORT-2-002

ok both port and starboard attached!

[Henry]

BEAR-FLAG-PROP-REPORT

[Rob Schepis]

Henry,

There are no attachments to your above post? Did you intend to attach the prop scans to your post or did you simply email direct to Tony?

[Henry]

TONY- Attached are prop scan reports. HENRY

[Tony Athens]

You do not read well——-

#1–Get your tach checked for accuracy at 2600 RPM, engine warm, at the dock in neutral, and WRITE IT DOWN

#2——-Call Gary and get a copy of the SCAN, otherwise you will have to do it all over again..

After you get the scan, send me a copy

[Henry]

Ok I’m convinced now…I am sending them into Wilmington.

Do I just tell him that I have 210BHP and the props need to be set to be able to reach 2750RPM? He does the rest?

Thanks.

[Tony Athens]

Henry,

You are a tough one to convince, but for now, remove the air cleaners, open a hatch and go for a run.. It will hurt nothing other than your ears.. I really doubt anything with change … 99.9% you are simply “grossly over propped” –( 300+-ish) .

#1–Get your tach checked for accuracy at 2600 RPM, engine warm, at the dock in neutral, and WRITE IT DOWN

#2——-Call Gary and get a copy of the SCAN, otherwise you will have to do it all over again..

Let me know when you decide you really want to get this fixed..

Tony

[Henry]

ok here is MORE information since I first posted this:

Tony I can’t seem to track down the prop scans but now I know it is only one engine, the port side, giving me trouble so I’m gonna assume, for now, props are ok.

1) When driving the boat all I can here is the port engine. The starboard side is practically silent compared to the port side. According to my PSI gauge it is about 55 on Port and 40 on STBD usually.
2)Dark smoke is now present, and light soot is accumulating on my transom. This is NEW, and has NEVER happened before.
3) In reading Tony’s low rpm article (for the 6th time) it HAS to be AIR or OVERPROPPED. For the moment I am assuming that it is AIR.
4) 300 hours ago I bought SBMAR S+B air filters. Never cleaned them. They don’t look dirty, and STBD side runs fine. Remember PORT side filter is OUTBOARD of engine room.
5) I inspected BOTH turbos and they look like the pics on this website that Tony says they should look like. Clean, no signs of water damage, just velvety carbon around the edges.
6) Replaced racor filters last week. They didn’t need to be changed but I did it anyway.

For a quick check to see if AIR is the issue, would it be a terrible idea to simply take the filter off and run the boat without the filter? I don’t want to clean the filters, hassle, and if it is the filter I will just buy a new one.

Help!

[Henry]

Ok. I’m on it. Stay tuned and thanks. Henry

[Tony Athens]

Ok, all is good so let’s pretends you are starting from SQUARE ONE with few exceptions..

 

1) Post and send me the prop scan that you must have just paid for.. If you don’t have it, ask Gary for it.. You have paid for it.

 

2) Your tachs have been verified for accuracy? If not, that is next.

 

3) Max RPM under load the vessel loaded conditions as you use the boat–after the tach are verified reasonably accurate..

 

This is really simple..

 

 

Tony

[Henry]

Ha Ha! I know, I feel like a dope for doing that. Just thought the prop experts would have all the correct answers. You should also know that I do actually have terrible vision!

OK  and- YES! I want my engines to perform at their peak. So let’s back up?

 

Thanks Tony. Henry

[Tony Athens]

Henry

Don’t take this wrong, but I would compare what you did  to going into an eye doctor  and telling him to give  me  a set of glasses without getting your eyes checked first………….Pretty amazing..

So, we are here and now……NEXT———- Do you want to get your engine to put out all it is capable of and get your boat to perform as best it can with the engines you have?  That is the question.. If you do, we will need to back up a tad..

Tony

[Henry]

Oh and Tony to answer one more of your questions, I had them tuned because I wasn’t making RPM underway, but that’s all I told them as well as what I COULD make at WOT. Thanks again.

[Henry]

Tony they can make it to 2900 no load…was just a little concerned to go that high figuring they might blow!

Good point on Wilmington. Guess what? I didn’t tell them anything, I figured that they just knew what my props should be set at. Sounds like a big mistake on my end, but don’t you think shame on them for not asking more questions about my boat, speed, WOT situation, etc? Just assumed they knew. Sounds like I’m mistaken.

So given this new information, and I’m very confident my tachs are correct, what do you suggest?

 

Lastly- I read all your stuff and yes I read the article you reference above, but my sort of exact situation  didn’t present itself in the article. Hence this forum post!

 

Thanks for all you and SBMAR do to help out the cummins marine community! You guys are great!

 

[Tony Athens]

 Henry,

 

Had the props “tuned” at Wilmington”?

 

Questions:

Why?  

What did you tell him as to your engines and boat specs?

Tuned them to what?

~~~~~~~~~~~~~~~~

Next: have you read this and applied what is applicable your your engines and situation?  If not, then until you do this, its ‘s really hard to guide you..

Understanding Low Power Troubleshooting

 

 

But, on the surface, think this: No load, your engines should go 2900+ RPM. You need to be sure your tach is accurate.. For propping purposes, use 210BHP at 2700-2750 RPM..

 

What exactly  did to tell Wilmington?

 

 

Tony

[Author]

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