Martek folding prop

[Navman]

I have a 1986 E-38. I purchased it a few years ago with a Martek folding prop. I like the performance and I believe it now need a maintenance rebuild. My questions is...does anyone else have the same boat with the same make prop? If so, what is the stamp on yours? Mine is a "ELIPTEC RH16D X 14P -3". Right hand, 16" diameter, 14 degree pitch. I wish to know if this is the same as others might have. I have been having issues with not being able to get up to RPM's of 2000 without the heat going up to the point where I have to back it down so as not to overheat. I have the larger HX, have cleaned it and reconditioned it, have replaced all of the hoses, have an entirely new wet exhaust system from the elbow out, have the Oberdorfer pump, impellers is good, have installed a sea strainer and still cant get it up to the recommended RPM's At this point it has either got to be the elbow or the prop pitch is not correct. I am putting a new T stat 185 degree this weekend and will check the hard fittings and elbows for clogging and build up. I can run at 6 knots steady but have recently seen that speed diminish When I first got her I would do 6.5 or 6.8 all the time. That is why I think the prop need a rebuild. During the last few weeks I am seeing a slight bit of steam in the exhaust. It disappears about 8 feet from the transom so that is making me wonder about the elbow. I want to be able to rev it up without overheating if I am bucking an opposing tide or big waves. Any thoughts or suggestions are greatly appreciated. Thanks in advance.

 

[Christian Williams]

For reference, wide open throttle with my 4-cylinder Universal 5432 and fixed three-blade prop, is 2700 rpms. Fast cruise is 2300-2400 for 6.5+ knots. Usually I aim for 6 knots at about 2100 - 2200--or less in easy conditions.

If 2000 is your highest rpms, well, that's a big difference from me.

 

[Baslin]

Had the same issue with mine. 5432 engine. When I bought the boat it was over propped. Once changing to the correct size (fixed 2 blade) the engine rpms increased but still not correct. I was also getting some white smoke out of the exhaust, but it never was overheating. What ended up doing the trick was when I replaced the muffler and increased the exhaust hose to 2”......

Have you tried changing both of the fuel filters? Also there might be some buildup on the bottom or on the prop.

Im not familiar with the folding props but is there a possibility that it somehow changed pitch?

 

[Mort Fligelman]

Martec Prop

Don: I really do not know how many times I have replied to threads about Martec Props....in all probability over the last twelve years on this forum I am sure the old timers are sick to death of my diatribes on this subject.....

Rather than subject them to it again please do a search and you will find all that I have had to say, and I might add all positive....

My immediate thought is that your problem is not your prop if it worked fine in the past....

As a matter of maintaining the boat I have every few years sent the prop to Martec over the winter to be checked out.....I have been very negligent in doing that on this boat, and the prop is now 12 years old.....no problems!

If you want to contact me back channel or by phone I am happy to be available.

Best

 

[Leslie Newman]

I would expect black smoke if your engine were overloaded. White smoke is steam from overheating. My Cal's 3GM30F was overheating due to restriction in the small elbow fitting screwed into the mixing elbow. Was getting white smoke (steam) out the exhaust. That elbow fitting brings the water from the heat exchanger into the mixing elbow. Check water flow out the exhaust. It should be a large amount of water flowing.

 

[Navman]

Martek

Thanks all.
Christian,
I have the same engine and could never really get it above 1850 rpm's. That seemed to be OK at the time because it was being driven at 6.5 - 6.8 knots steady 24 hours on end. If I were to push it to higher rpm's it would begin to get hot 200 degrees - 210 before I would have to back it down. I had thought 1850 rpm's, that's OK because it is being driven at nearly hull speed so I wasn't worried about it. More recently however, the same 1850 rpm's is not getting me up to previous speeds. That is why i removed and cleaned the HX and put new hoses on it.
Baslin,
I will change out the fuel filters. The entire exhaust system from the mixing elbow to the transom is new and is 2" so I do not think that is it. Hench my thoughts about the mixing elbow or the t- stat hard piping being clogged or reduced in diameter. Next time I go down I am going to dive on the boat and see if there is any buildup of barnacles etc. on the prop and shaft as that could also have an effect on speed/ performance. I did dive on it earlier in the season and did clean off a pretty good ( not so good) amount.
Mort,
The blades on the folding prop are beginning to touch which is an indication of wear and I will be sending the prop to Martek over the winter for a rebuild. I was thinking perhaps the play in the props is causing some additional vibration also which could in turn be affecting performance. I do really like the performance of the prop in both forward as well as reverse. I really have no idea on the age of the prop but due to the amount of wiggle in the blades I am sure it is overdue for a rebuild. Getting what I think is good water flow out of the muffler.
Leslie,
Good to hear from you. We haven't corresponded since you did your delivery this summer. So close when we were in Solomons but just couldn't make it work. I will take the elbow off and see if it has build up inside. Thanks for hte suggestion.

Well, ultimately this all means I have a "work weekend" coming up on The Optimist II. To be expected with boat "moanership".

 

[Christian Williams]

Your numbers are not too different from Craig's in this thread (#5 post):

http://www.ericsonyachts.org/infoexchange/showthread.php?15644-Universal-Diesel-5432-Cruising-RPMs

It does raise the question of whether the tach is accurate--they're subject to error, and some have settings on the back that radically change the reading to accommodate various engines. When I installed my last one, I just chose the setting that gave 800 idle and about 2800 max rpms.

Anyhow, we are told to run at 80 percent WOT, and avoid low rpms. Despite all the opinions, this seems to be general wisdom.

 

[Navman]

Martek

Christian,
I had thought about the tach being off. When I do goose the rpm's up from 1850 it only increase speed ever so slightly and like you said it begins to squat. So I back it down to the sweet spot 1850. Less vibration better consumption. I did about 250 nm of motoring coming down to the Chesapeake from Block Island and averaged 6 knots at a rate of .65 gallons per hour. I round it up to .75 per hour as a safety factor when calculating remaining fuel. Well, looks like I am going to purchase one of those Tach kits. Just reflective tape and a gun. Not very expensive. Another project for the work weekend. That weekend may need to be extended with all the irons I have in the fire. Not that a longer weekend on the boat is a bad thing, just saying......

Thanks,
Don