My new to me 1987 C34 is struggling to get above 2300 RPM underway. It was hauled and bottom cleaned on June 24th for survey. On delivery home I had some steam coming from the exhaust and it was running a bit hot at higher rpms so we throttled back. New impeller solved that problem. We've only had it out twice for short motoring trips since getting her home due to lousy weather. Took it out yesterday to knock some crud off the bottom and we were very slow across the bottom (GPS speed). I ran it up to full throttle and it only got to 2300 RPM and just over 4kts. I throttled back, shifted to neutral and ran up the throttle and it was well north of 2500 rpm and climbing so I throttled back thinking the issue isn't with the tach (even though it had acted up on the delivery home. Cleaning some terminals seems to have solved that issue). Water temperatures are abnormally high so growth on the prop is possible. I'll check it with a GoPro today. Could anything else be contributing to the low RPM and speed? I'll check the packing nut temp today while running it in the slip.
Thanks
John
John,
My first thought is dirty fuel filters. That's the symptoms I get when the filters need changing. Engine runs fine but won't do full RPMs. And a recently changed filter can be dirty. Lots of information here on changing fuel filters and the filter of owners choice 2, 5 micron or even more course. Easy job if all goes right. I've even changed them underway.
Hope this helps,
Jim
Thanks Jim. I'll check them out and replace. I have no idea when they were last replaced so this will get me on a regular schedule.
John,
You took it out to knock some crud off the bottom, don't you have a bottom guy? Jim's got the right idea with the filters, but I think I'd just go ahead and do a 100hr service which would set up a good performance baseline and then you can start looking for problems related to individual issues, like low RPM, overheating, etc.. Also when the impeller was replaced were all vanes in place or accounted for?
Kevin, I do have a bottom guy but with my old boat twice a season was plenty. With a full pressure wash on the 24th of June I really wasn't expecting that much of a problem, but new boat to me so who knows. We'll see what the GoPro shows shortly. I did find all the vanes when changing impeller. It is running at about 165 after almost an hour of motoring so I'm feeling good about that issue. Oil and filters were replaced just before I bought the boat. I'll do a search for what else is on the 100 hr.
John : If the new filters don't help increase the engine, look at the RACOR " Obscure check valve" as Stu posted above!!
Also there was a screen on the end of the fuel pickup tube in the fuel tank. I wrote about this over 25 years ago, but you might check it?
That screen can clog, and was eliminated in the 1993? C34 production.
If the boat has been sitting for the past 6 weeks you might check the prop for growth!!
A thought
John, I am not familiar with the fuel system layout of the Mk-I, but my Mk-II will run quite nicely without the electric fuel pump operating. However, it will not get close to full engine speed. The wire to my fuel pump broke and it took me a couple of weeks to find the problem. Check the fuel pump is ticking.
John : That has been posted a number of times - as the fuel tank is higher than the engine (syphoning!!)
a thought
In addition to the Racor, and on engine fuel filters, the original '87 fuel system tank pickup tube had a hose with a strainer on the end that can clog up. Unfortunately it's all inside the fuel tank. Before tackling that nightmare, is the Racor filter bowl full of fuel? If it is, the strainer inside the tank may not be the problem right now. Checking for and removing the strainer, is something you should plan for.
My 2002 MK 2 also would not run over 2,000 rpm. Replaced the electric lift pump and has been fine for 5 years. Check the pump.
Quote from: Dave DeAre on August 10, 2020, 06:21:45 AM
My 2002 MK 2 also would not run over 2,000 rpm. Replaced the electric lift pump and has been fine for 5 years. Check the pump.
I purchased a spare pump shortly after buying the boat. I'm kinda anal about spare parts. I'll be checking the existing pump tonight. Perhaps it isn't even working and I'm just getting gravity feed per Ron.
BTW, my Racor is a 500FG Turbine series so Stu's clean out doesn't seem to apply to my situation unless the ball valve is somewhere else. I'll be looking into that tonight too.
New filters are on their way. Hopefully I'll have good news to report. Thanks for all the insight.
John
Quote from: Oldlaxer1 on August 10, 2020, 10:55:03 AM
>>>>>>>>>>>>>>>
BTW, my Racor is a 500FG Turbine series so Stu's clean out doesn't seem to apply to my situation unless the ball valve is somewhere else. >>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>
John is right. I just Googled Racor 500FG Turbine and the Parker manual says a separate check valve should be installed if the fuel tank is below the filter/housing.
Just like I "discovered" this little gem: RTFM. :D :D :D
I had a similar problem in a prior boat that was Yanmar powered. It turned out the exhaust mixing elbow had rusted almost completely shut. It would also get steam since there were tiny holes in the elbow. I haven't dug into the Universal enough to know if it's laid out the same way, but might be worth looking at.
I'm definitely hoping it is a filter or pump issue....That exhaust manifold is almost $1,400.00.
John : Your exhaust riser mixing tube is stainless steel - not like the Yanmar that can rust.
A thought
Quote from: Oldlaxer1 on August 10, 2020, 02:12:43 PM
I'm definitely hoping it is a filter or pump issue....That exhaust manifold is almost $1,400.00.
What part are you referring to? The exhaust riser for the M25 series engines is about $275 plus cost of the thermal wrap.
Quote from: Oldlaxer1 on August 10, 2020, 02:12:43 PM
I'm definitely hoping it is a filter or pump issue....That exhaust manifold is almost $1,400.00.
John, as Noah said, you don't need an exhaust manifold, you need an exhaust riser. Two different things. The manifold is the big rectangular piece that you pour antifreeze into.
I wrote a Tech Note about replacing the riser, along with the muffler.
Feb 2016: https://c34.org/muffler-exhaust-riser-replacement-2015/
Hi John, glad you've got the boat, but sorry you're having an issue.
Don't assume that it's not growth. I was furloughed May-June and used the boat 3-4 days a week until June 26. The bottom looked the cleanest it has ever been at that point of the season. Then I went back to work (and the crap weekend weather), so the boat sat 5 weeks until August 1. During that time, I spun the prop in the slip once a week hoping to slough off any barnacle larvae before they could mature. Despite that, we took it out Aug 1 just to test the motor, and it had a hint of vibration at 2400, and >2500 was crazy bad (like would probably destroy my stuffing box). I hired a diver who cleaned the prop Saturday and took the boat out, and it ran fine all the way up to 3100 RPM. He said that this has been a very bad year for hard growth due to high temps and salinity. As evidence of this, you can see the sea nettles coming further north than it has in several years.
I know your symptoms are a little different than mine, but I'd say there's a good chance your prop is fouled. Hire the diver and then see how it runs.
Quote from: Noah on August 10, 2020, 02:48:11 PM
What part are you referring to? The exhaust riser for the M25 series engines is about $275 plus cost of the thermal wrap.
Remember also the water-cooled riser option....
https://c34.org/wiki/index.php?title=C34_Exhaust_with_Water_Cooled_Riser
That some said couldn't be done (-sorry couldn't resist.)
Thanks everyone. Filters arrive tomorrow so that will be the first thing I do. I need to get on a schedule anyway so it is not a bad thing even if it is growth. Not looking forward to changing the engine filter but I'll get it done. I went down to the boat to make sure the fuel pump was "clicking" and it was as soon as the key was on. I purchased a pressure gauge along with the filters for the Racor so I can monitor fuel pressure. I had one on my last boat and it was helpful.
We're scheduled for a 5 day cruise over Labor Day weekend so I'll probably schedule the diver a week prior to that.
Exhaust riser, not manifold, got it. Thanks...
QuoteFilters arrive tomorrow so that will be the first thing I do. I need to get on a schedule anyway so it is not a bad thing even if it is growth.
I hope the filter change goes well and totally fixes the problem. "But" if you have dirty fuel they may need changed again after only a short time running. I always carry several new filters. I suggest you spend a little extra time when changing the filters to cut a plastic bottle or something to fit under the filters to catch any leaks, also at least one roll of paper towels.
Hope you have a good trip,
Jim
Where are you on the bay?
We keep the boat at the Anchorage Marina in Baltimore.
Just an update.....it was growth on the bottom and prop. RPM's and speed are back where they belong. I will be checking prop pitch when I haul her. I'm thinking with an adjustment I can improve speed a bit without lugging the engine. Happy Labor Day weekend for all us laborers out there😎
John : If the boat has been doing a lot of sitting for the past 6 weeks you always need to have a diver check the prop.
If you dive under and look at it the prop the blades will look like "Boxing Gloves"!!!
A thought
Not sure what your growth rate is like in Baltimore but here in SoCal we get the bottoms done every four weeks and by the end of the fourth week that bottom is looking pretty grungy, especially in the summer.
John : Don't know what kind or brand of bottom paint you are using, but bottom paint usually does a pretty good job with keeping the barnacles off the painted surfaces. You might get some slime while sitting awhile.
The running gear like the prop is a different matter! It's a constant battle to keep the "nasties" off the prop - many, many post on that topic!!
A few thoughts
Hi John,
I'm glad the diver cleared things up for you. Looks like my initial hunch was correct.
This is the first year I've had to hire a diver to address vibration due to hard growth on the prop - my prior four years with the boat, everything worked fine throughout the season, and at haulout there would be 5-6 barnacles on the prop, always in innocuous places (i.e., near the hub but not the outer parts of the blades). Last year there was an extreme number of barnacles on the brand new strut that I noticed after haulout.
For the past 5 years I have used Pettit Prop Coat Barnacle Barrier on all running gear. It has helped when compared to untreated surfaces, but it's far from perfect. One guy on Sailnet (who has now been banned) repeatedly swears by Prop Speed (2-part epoxy? paint followed by clear coat, I think), but it's way too overpriced for my tastes, and this same guy still has to hire a diver a couple times a year. If I were paying $300 for prop paint, I'd be very disappointed if I still had to hire divers. Also, I'm concerned that any 2-part curing paint like Prop Speed would be very difficult to remove down to bare metal once it needs replacing. The guy who runs the nearby prop shop in NJ told me that he'd only recommend spending the money on Prop Speed for huge powerboats with huge props. He sells the $28 Pettit stuff for 95% of his customers.
There is now a lower cost competitor for Prop Speed called Prop Glide. However, it's still pricey (close to $200 IIRC) and, I suspect, difficult to remove.
This year I applied the Pettit stuff again, but overcoated it with some copper-free Pettit Hydrocoat Eco that I picked up on clearance from Defender. I won't know how it worked until haulout, and it won't really be a legitimate comparison vs. prior years because I hired a diver for the first time this year.
My comments here are relevant to my area in the mid-upper Chesapeake (Rock Hall). I know that you're right across the Bay in the Patapsco, which is generally similar, though probably even more nutrient-rich.
A guy got banned for recommending a prop paint?
Quote from: scgunner on September 07, 2020, 07:04:20 AM
A guy got banned for recommending a prop paint?
I don't think so. I'm not sure why he was banned. But he is unavailable for answering any questions that John may have, which is why I mentioned it.
Guys : The 1st person to come up with a "for sure" coating that will keep barnacles off the running gear(especially the prop) will become a zillionaire!!!
The US Navy has paint/coating, but not for commercial use. A friend got some and painted his running gear (wearing a hazmat suit) and there were no barnacles or anything growing on the pilings for 10 slips on either side of his slip!!
A thought
FWIW - I just watched a sailing video where the guy was reviewing the anti-fouling he applied to his prop and prop shaft 18 months ago. After sailing from Florida up the East Coast, across the Atlantic, and having the boat sitting due to the lockdown, there was zero growth of any kind on his propeller and propeller shaft. The paint is a silicone paint called SeaJet Pellerclean. The US distributor is supposed to be CMP Coatings Inc in New ORleans, but couldn't find any information on their website.
Ron,
Well that sounds safe, wonder what would have happened if he'd painted the whole bottom! I thought I read something about the Navy either using or experimenting with some type of a low level sonic resonance to repel marine growth.