Suzuki 2000 DT140 extreme cooling corrosion

[bneugent]

The boat/motor has been in the shop for a month. The first mechanic replaced the water pump three times but the Suzuke still overheated in the water. The second mechanic (much more knowedgable about the Suzuki) replaced the Thermostat which was excessivly corroded and broken in three parts. Then took the boat for a test drive. Low speed was fine but it overheated at top speed and did not show a notable increase in the tell tail as the RPM's increased. This mechanic suspected a problem and took everything apart. His words were that this 6 year old motor looks like a 20 year old one run in salt all the time. everything had to be scrapped and cleaned. everything had excessive pitting<br />Now the question: <br />What could cause such extreme corrosion in a relativly new motor??<br />Should I and should everyone wash it out with fresh water after each trip?<br />Does this level of corrosion limit the life of the motor? <br />More info about the situation: This year is the first time I replaced the zink. While it had lots of holes it still had its basic shape. I thought it was OK. Most of the time the motor was out of the water after a trip but as the weather turned cold (about a month in the fall) I would often keep the motor in the water to keep from freezing the lower unit. It was rinsed well with fresh water at the end of the year and tarped for the winter. <br />Many thanks for any advice<br />Bob

 

[rodbolt]

Re: Suzuki 2000 DT140 extreme cooling corrosion

yep, a fresh water flush after any salt or high mineral water use, use of the correct anodes and keeping the anode surface clean.<br /> if the anode is not dissapearing odds are its either calcified or lost its electrical bond and is now just another piece of metal along for the ride.<br /> how often do you use sandpaper to clean the deposits from the anode before launching?<br /> once its got that white powdery coating its a usless piece of metal.<br /> 6 years in saltwater is an average life span for a saltwater cooled aluminium block/head assy.<br /> frequent flushing and anode maint will help some.

 

[bneugent]

Re: Suzuki 2000 DT140 extreme cooling corrosion

Thanks for the information.<br />I have not used sandpaper to clean the anode but will pass on the information to the many fishermen at my dock. The truth is I have not paid detailed attention to the appearance of the anode. <br />Kind of shocked at the 6 year life expectation of the aluminium block/head assy. It changes ones perspective of dock maintenance and of aluminum. <br />I can't tell you of how many things I have learned the hard way since buying a new boat 6 years ago. <br />Do you know of any publication that gives a good overview with practical applications for the care and feeding of the average 20 foot boat in salt water? I have seen pieces of great information in different places but not one good reasonable publication that covers electrical, fiberglass, all of the basic utilities and the outboard.

 

[rodbolt]

Re: Suzuki 2000 DT140 extreme cooling corrosion

alas not really as such a book would have to take in to many environmental factors not to metion physical factors, best bet is find a tech and love them dearly that understands what and why the anodes are in place.<br /> I see boats go over daily with white anodes that are just dead weight.<br /> no one listens so I say nothing.<br />it also does not hurt to check the resistance of the anodic circuits as well as the bonding circuits occasionally during the year.

 

[bneugent]

Re: Suzuki 2000 DT140 extreme cooling corrosion

We have a very tight group of fishermen at Grays Marina on the Pawcatuck river. Your advice will be well delivered and used. I they will take more care of their anode when they see my bill and I will do the resistence checks as most will probubly not know the difference between .3 ohms and 30. So the anode was probubly dead weight last year which made the already corroded aluminum that much worse this year. <br />Again thanks - Tomorrow will be time for Black fish off Fisher Island rocks and Fluke off the westerly beaches. <br />Bob

 

[rodbolt]

Re: Suzuki 2000 DT140 extreme cooling corrosion

good luck, way to much NNE wind to fish here this weekend

 

[bneugent]

Re: Suzuki 2000 DT140 extreme cooling corrosion

I am continuing this saga of the overheating 140 so people who have a similar issue will have a concept of the road they will need to walk. <br />Soon after I turned the motor on after the work done above the tell tail started strong and looked good. The motor heated up and the tell tail weakened. Then the motor overheated with a beep beep beep of the sensor. I took off the cover and found the power head quite hot. I let it cool down and then turned it back on. The tell tail was week so I increased the RPM's. At increased RPM's the motor was staying at a comfortable temperature and the tell tail while not robust was better. Took the boat for a spin and operation at the higer speeds seemed reasonable with a reasonable tell tail. Back at the dock at idle it quickly overheated. <br />I talked to the mechanic who said that there are pressure valves under the power head that could cause this but that he would have to pull the powerhead to get at them. On Monday he is going to call Suzuki to review this condition before he starts the 6 hour engine pull. It is odd in this series of events that the tell tail started with such gusto befor it trailed off. Also started the boat stone cold in the water again and the tell tail continued to be poor. ???

 

[rodbolt]

Re: Suzuki 2000 DT140 extreme cooling corrosion

the pressure contol is in the cyl head I think but it require head removal to access. they may have changed the design but on the mid ninties inline motors it was a spring and a valve in the cyl head.<br /> of course with a suzuki its possible a casting has corroed through on the powerhead adapter as well.

 

[bneugent]

Re: Suzuki 2000 DT140 extreme cooling corrosion

Rodbolt - Thanks for the additional information. Looking at the thermostat I would expect anything in this salt water path to have failed. I will ask the mechanic to examine the power head adapter. <br />Resorted to a long walk out to a bluff where I caught a few school stripers. nice to bend the pole <br /><br />Bob

 

[rodbolt]

Re: Suzuki 2000 DT140 extreme cooling corrosion

always a good thing when the pole is bent, heck I have even had fun fighting oyster beds .<br /> if ya ever wanna step up to the pump and bend a pole in south america(venezuela) for the price of an outerbanks vacation , let me know. hopefully my peacock bass trip pics will be online next week .<br />but snook and tarpon can be had for 2K less.

 

[bneugent]

Re: Suzuki 2000 DT140 extreme cooling corrosion

Look forward to the Pics. Venezuela sounds intesting. The bent pole is just getting started up here. I hear the squid are in and that brings everything.

 

[jprasisto]

Re: Suzuki 2000 DT140 extreme cooling corrosion

CptBob please do keep us updated. I have twin 2003 DF 140's used in salt also and I'd be interested to hear what is up. There was another thread here a while back about pitting in the lower unit which actually let water into the unit and blew it out, all on new engines! I do flush mine after every use and change all zincs, including the ones on the trimtabs of the boat. Just make sure not to paint over, or under, the zincs. I think I disagree with rodbolt on the 6 year life expectancy though. I replaced my 1986 evinrudes in 2003 and they actually are running on another boat right now. One engine had a new powerhead due to overheating when I picked up some eel grass in through the intakes. Yuck! My '03's look brand new inside and out.

 

[bneugent]

Re: Suzuki 2000 DT140 extreme cooling corrosion

I think Rodbolts comments included the concept that every patch of water has different characteristics. In reviewing the gaskets to my motor I saw gaskets in the lower unit that prevented salt water flow from the water pump to the lower unit so corroded that the corrosion had pushed them up 1/32" of an inch and the new water pumps installed in my first comment in this chain were damaged instantly because the 1/32 inch compressed them. Three of them. This gasket would have failed in the next year which would have failed the lower unit. A gasket on the head showed corrosion between the one of the cyinders and the water jacket that makes one believe that a very small leak could have been started. Plugs were burning very hot which supported this idea. At this point I think the motor was ready to implode. My slip is not full salt water. It is at least half fresh, probubly more, and I always thought that it would give me more time on the motor. That was obviously a false sense of security. Great that you are washing it out each time (wish I could say the same) and I know Rodbolts comments on the zink are crucial for all salt people. Also I have a great friend with a 2002 DT140 That is showing some significant corrosion issues. I will pass on his story also. Did you know that you have zinks internal in the water jacket. Obviously this change in Suzuki's design is the result of past warrenty issues. They were giving a 6 year warranty. This is actally my first year without a warranty. If I were you I would put the internal zinks on a list to check. Good luck <br />bob<br />PS-Pick up my boat - motor on friday and if mother nature allows and they finally fix this motor I will be trying for fish.

 

[rodbolt]

Re: Suzuki 2000 DT140 extreme cooling corrosion

disagree dont dissagree its a fact not a fancy,<br /> I know where an 89 kinda 140 ev that is all salt has maybe gets a flush once a year when it gets put on the trailer, I built it for the man in aug of 98 and fuel tickets in the spring on 05 revealed slighty more than 13,000 gallons of gas has passed through the OMS oil pump.the first block had corroded a hole through the block just under the headgasket and was spraying water by 1997, the curent block is a small bore 85-86 type. I have seen others corrode holes into the crankcase and through the cylinder head and a few blow out the powerhead adapter. its an average, to move the average some make it a loooong time and others not so long.<br />whats funny is to see a nice shiney trim tab zinc tilted out of the water where its absolutly usless.

 

[bneugent]

Re: Suzuki 2000 DT140 extreme cooling corrosion

This is just to close off the final successful repairs. Replaceing the pressure control valves corrected the water cooling problem. I had him check the head adaptor which was fine. Noted that 1/2 to 1/3 of the outboards in the marina were in the water with the lower end touching. Mentioned it to the owner and mechanic and they understood the dangers. Mentioned it to a friend who wouldn't believe anything could happen with the power disconnected from the motor. Put the boat in the water on Friday 5/6 and took a 40 mile round trip on Saturday 5/7 to Montauk. The Suzuki runs much better (I think the corrosion between two cylinder heads indicated a water leak into one of the cylinders) so I had more than a water flow issue. Caught two 5 pound + fluke at Montauk along with a pile of small ones. Yes it was worth it.<br />Bob

 

[rodbolt]

Re: Suzuki 2000 DT140 extreme cooling corrosion

its always worth it when ya make it back

 

[chanice]

Re: Suzuki 2000 DT140 extreme cooling corrosion

rodbolt please advise if poss (sorry to jump on some one else ,s wagon \ only way to get you! <br />can you tell me what the readings should be on the water flow / temp guage of a dt 100 that is the three wire version at present the flow reads zero ohms to infinity from the on/off so seems ok<br />the temp guage reads 100K cold and same when in boiling water??? seems too me thats wrong please post to chanice thanks (live long and prosper)