[Brian]

Racors and last-chance filters changed. Topped off fuel, sea trialed last night, problem solved! Wish all could be so easy.

David, gaskets are fine at fuel fill. Thanks.

[Brian]

Rob:

Thanks. Yeah, I found last night easy enough. Takes a while to prime with those but got it done. Racors were absolutely loaded with algae, especially starboard side. I never saw it this bad and need to keep a closer eye on them. Put 30 micron’s on knowing I’ll be changing again in a week or so but I want to clear this up. Also a pair of vacuum gauges so I can monitor a bit easier. I’m going to start using Biobor JF religiously. I never really had a problem with my fuel based on where I had formerly purchased. I switched to a new location a few years back and this problem has become more prevalent, despite their being a large volume seller. Seeing this there is no question my RPM’s were impacted. I’m surprised the motors ran as well as they did. Going to top off tanks tonight and do a quick sea-trial. Looking forward to seeing the RPM’s back to normal. Fingers crossed!

Thanks again for your help.

Brian

[Brian]

Hi Rob:

I think they are struggling to make WOT RPM’s but fall off before reaching. Then the cycle starts up again a short time later. The more I think about it the more I feel that’s all it is. I’m pretty certain it’s the filters. Changing tonight with hopes it’s as easy as that.

The lift pump – little black button right close to filter? I think that’s the color. I noted location last time I was down there.

[Brian]

Hi Rob.

Thanks. 10-4 on the “480 CE'” name. Good point.

I think we’ve crossed paths in the past. You sent me a photo of my boat in fact. Small world.

The first thing I thought about was getting ECM’s flashed/updated but getting Cummin’s marine out takes an act of God and they are not cheap. My engine sync seemed to be acting a little odd and I may have screwed things up through adjusting the RPM using the bridge +/- RPM switch. I was also out in some snotty weather last week and fuel was less than 100 gallons before I topped off. (I never run that low) Things may have sloshed around in the tanks and perhaps its as simple as changing the Racors but tell me, could that decrease my WOT speed then? Not that I run WOT but the fact that it is now seemingly restricted bothers me and I need to address. My guess is that possibly, but I’ve never experienced this before. I also wonder if the system I have with the engine sync has memory which perhaps I can clear buy removing all DC power for a period and then reconnect. Is essence, a reboot to resolve my messing with the RPM control and perhaps clear the sync allowing WOT. Coincidentally, my programmed engine cruise control speed is 2400 RPM and that is about my ceiling right now. A bit less than the 2600/2650 I formerly saw. (This was calibrated by Cummins several years ago when I had them out to flash the ECM.)

On another note, racors are easy but when changing the fuel filters on the engines, would I need to bleed the system? I keep spares but have always had a “real” mechanic throw those on. Thanks.

Brian

[Brian]

I’ve got 6CTA 8.3’s on my boat and started experiencing similar issue. Seems to only affect starboard side motor. I cruise as 2400 RPM. It will drop to 2200 or so and then recover. This occurred yesterday on way back from long trip. Both engines also seem to max out at around 2450-2480 RPM. Just a few weeks ago I would see 2600 +/-. Have not had a chance to look at or change racors yet but think maybe the fuel I purchased could be the cause. (I hope) Wondering if I sound also replace the filters on the engine for piece of mind. ???

[Brian]

Thanks. Yeah, I read than already. When I open what should I expect to see or not see?

[Brian]

Negative. That was my plan. I should get new gaskets before I do that correct?

[Brian]

I had marina remove aftercoolers and service. I provided your protocol/instructions to them and requested that it be followed.
I was advise they did so. I had oil test completed and it cam back fine. I wanted to make sure there was no sea water in the oil and confirmed there was none.

They did not service HX and I want to have that done . Wondering how far I really need to go with that. Gets pricey with these guys.

Just had friend who has Cummins in a 480 Sea Ray Express and it cost him 3K per engine for complete sea water side servicing.
1100 hours on his boat. That work was done by Marine Max on east coast.

[Brian]

Yes, aftercoolers done this past winter. Thinking servicing the HX but could I just inspect for obvious debris and replace gaskets or is that a waste of time? Water pump (SBMAR) impellers replaced last year. Need to buy spares and gasket kits as well. SMX Super 17 Impeller and 1730 seawater pump gasket and o-ring kits, right? 2005 480 CE’s. Thanks.

[Brian]

Noticed after running motor to temp heat exchanger coolant hose collapses on itself as if subjected to slight vacuum, perhaps caused by coolant when engine cools down. Is this normal or should I replace this hose as well?

[Brian]

Thanks. I will check hoses, etc. and post results.

[Brian]

Thanks Rob. With respect to servicing the heat exchanger, would a simple visual inspection along with gasket replacement and typical zinc replacement suffice or should it be removed? Of course this is as long at there is nothing noted upon. What about the area areas of the water circuit/coolers? I will check hoses this weekend and order rebuild kit for heat exchangers from SBMAR and attempt to do as much as I am able with hopes I can resolve issue but I fear there may be a time when I will have to retain a qualified Cummins guy locally to come in and address. Unfrtunately, ther is no one around my area that I feel comfortable with at this time. The guy I formerly used is semi-retired.

We get to Greenport, Shelter, Sag Harbor, and Montauk often. Majority of our trips are further north to Block, Newport,
Martha’s, etc.

[Brian]

All good thoughts regarding hoses and easy. I’d say no, none have really been examined in fashion you suggest. How stupid would it be if it was a degraded hose from strainer to pump?

A plumber/boater friend of mine were actually talking about taking temp as you mention.He’s bringing IR down this weekend.

Quick thoughts on cooler inspections? It was once suggested that I use muriatic acid cut with water in heat exchanger and trans cooler for 30 minutes and then flush. I hate working with the stuff and would probably allow a real wrench to deal with it.

Yes, I do recognize where you were. Got to love Mystic. Where is home port? We hit LI often. Thanks for the thoughts.

[Brian]

BTW, you’ll notice at the tail end of the first video taken from inside the bridge that the vapor is all but gone when I back down.

[Brian]

Yes, that me in my home slip. You must be at Red 36. Too funny. I’ve seen your boat as well. One of 4 Tenacious’ I know of in my waters and to the north.

To answer your questions yes, the spray rings. See photo’s below. No debris or clog. Pumps replaced about 3 years ago with SBMAR pumps and then rebuilt last summer with kit which was sent along with them by Bayside, the wrench next to my slip, along with all the other work done at that time. Motor’s had about 750 hours at the time I began to notice. 802 hours today. The issue has subsided a bit since the aftercooler rebuild which took place over the winter but still exists. I’ve had mechanics tell me it’s vapor/steam as it does dissipate when I back off from 2400 RPM. I upload two videos onto youtube which you can view at the following links. I’d be interested in anyone’s thoughts. I did speak with Tony this morning and he feels it could be a blockage or restriction somewhere. I’m waiting to hear back from him.

[Brian]

Yes, that’s me in my home port. Looks like you’re at Red 36. Too funny.

I spoke to Tony earlier today and am waiting to hear back but to answer your questions, I replaced both pumps a few
years ago with SBMAR pumps. Last year had serviced (at Bayside Marine, next door to my boat) with SBMAR kit that
came with pumps, replaced impellers, etc., plus all the other items I already mentioned. Yes on the spray ring. The
photo below is was I was speaking of. Clear of debris. Never had issue with impeller breaking up either. Motors
probably had about 750 hours when I began to notice. 802 hours today. Tony feels obstruction somewhere. Never
had heat exchanger serviced so maybe start there.

I just put up these videos on Youtube. Took last year. Better this year but still there with after-cooler rebuild, but
still there. I’ve had mechanics tell me it’s vapor not smoke. Some say its normal. I disagree as it only recently started
to occur. You will see two different angles in the videos. I can turn a wrench but in no way consider myself a mechanic.

[Author]

Replies