White Smoke at Max RPM (21-EC)

[Rick & Karen]

Hi Everyone,

I have not seen this discussed on the Forum so I thought I would ask. Under load, with a clean prop and bottom, Kolo Iki's max RPM tops out somewhere between about 3050 and 3100 (previous topic, I know). When running like this I have noticed a cloud of white smoke being discharged out the wet exhaust outlet. When throttling back to a normal cruise RPM of 2400, the white smoke pretty much dissipates as the RPM bleeds off (there is still a slight trace at 2400 RPM) . When placing my hand in the smoke there is no oily residue of any kind, which leads me to believe it is only steam coming from the exhaust system.

The ambient year round water temperature in Hawaii varies anywhere from 76-81 degrees, which I imagine is 25-30 degrees cooler than the areas many of you run your tugs, so maybe this is a contributing factor to the exhaust smoke. I have read that sometimes steam will be generated when running diesels with raw water engine cooling systems and I thought I would ask if anyone else has experienced this phenomena. Any thoughts on this would be appreciated.

Aloha,

Rick

 

[Rick & Karen]

A couple of more things to add. When running at max RPM there isn't any excessive fuel odor. All fluid levels are normal (oil and freshwater cooling system) and the raw water intake for the sea cock is clean as is the water strainer. The impeller was replaced at 131 hours last summer and there is approx 180 hours on the engine now. I flush the heat exchanger with fresh water after most outings, so I am making an assumption that it is free of any blockages.

I did find a very similar topic at the below link:

http://www.yanmarhelp.com/s_faq.htm

Regards,

Rick

 

[K7MXE]

Aloha
You may want to consider a compression check. It needs a port and usually could be done at the glow plug. The motor will have to be disabled so it does not try to start. Bad compression may mean a bad gasket that seeps on high rpm.
It may smoke if the theromostat is removed and the motor is running cold. Being fair I dont know as much as I should on diesel motors but thats a start. White means water, Black smoke is too much fuel, Blue could mean the rings are tired and clear is a good thing. I am to assume no white sludge forming at the point where the oil goes in as I think you have a pre smog engine. Smog motors came early in the 06 model run if I remember my history right. My Subaru mountain car has that sludge buildup in the oil cap and I know its tired! Bob Heselberg Eatonville Wa

 

[rt11002003]

K7MXE is pretty much on target. I'd add that black smoke is also an indication of an overloaded diesel engine. Watch the exhaust on a tractor trailer truck when shifting, it gets too much fuel and the engine also loads up during the shifting cycle.

I don't know the specs for max rpm of your engine. But, if it is propped correctly it should max out under load at rated rpm (should be on engine data plate). However, I don't think max rpm is part of your issue.

Occasionally, my 2009 R21EC will do exactly the same thing your vessel does, billow a white cloud at max rpm. If one can't smell, taste or feel diesel in the plume, it's steam. Engine temperature increases as rpm increases, after running for a while at max rpm conditions may be right for producing steam in the exhaust stream. Unfortunately, our engines don't have a temp gage. I used to watch the temp increase on the Yanmar in my Albin when I increased rpm from cruise to max. Temp always increased the same amount, 15 to 20 degrees depending on raw water temp.

Sludge is a separate issue. It's a by product of internal combustion blow by and of engines that aren't run hard and/or long enough to burn everything out. Perfectly normal in automotive engines.

Gene

 

[dloop]

My fairly new 21-ec (2010 model) has this happen as well. Max RPM is 3800 under load, but at around 3200 steam will start to be seen at the exhaust. It gets more pronounced the higher the RPMs go from there.

I was originally concerned but I checked with Andrew and he said this is normal. He said he often witnesses this himself when he is testing new Rangers. As long as there is plenty of water coming out of the exhaust he said the impeller is working and it was probably OK.

When I researched this, I also found references to much older 3ym30's that had a heat exchanger warranty issue that caused this as well. A number of sailboaters reported it. But I doubt yours is that vintage.

http://www.cruisersforum.com/forums/f54/yanmar-3ym30-overheating-4576.html

dave

 

[Rick & Karen]

Aloha
You may want to consider a compression check. It needs a port and usually could be done at the glow plug. The motor will have to be disabled so it does not try to start. Bad compression may mean a bad gasket that seeps on high rpm.
It may smoke if the theromostat is removed and the motor is running cold. Being fair I dont know as much as I should on diesel motors but thats a start. White means water, Black smoke is too much fuel, Blue could mean the rings are tired and clear is a good thing. I am to assume no white sludge forming at the point where the oil goes in as I think you have a pre smog engine. Smog motors came early in the 06 model run if I remember my history right. My Subaru mountain car has that sludge buildup in the oil cap and I know its tired!

Hi Bob,

Mechanically I think my engine is okay. In neutral at the dock, I can attain full rated RPM. I am thinking of trying that later today with the bucket and garden hose setup to see if there is any steam from the exhaust (might be a partial lower water volume issue while underway). I bought the boat with 65 hours on the Hobbs and I have changed the oil twice and am now running Amsoil's synthetic marine diesel oil. Looking inside the engine through both orange oil filler caps, everything I can see is clean as a whistle and looks brand new.

The max RPM issue has been visited before on the Forum and I don't think that my boat has ever obtained more than approx 3200 RPM "indicated" under load. From what I have read here, that does not seem to be outside the realm of other owner's operating experience. I will admit to being very surprised by the recent post of a 2010 (I believe) R-21 EC tug owner who reported seeing 3600 RPM on the tach while underway. Short of the factory making changes on the new model, like a different prop, I do not see how that is possible. As always, I appreciate your insight.

Aloha,

Rick

 

[Rick & Karen]

My fairly new 21-ec (2010 model) has this happen as well. Max RPM is 3800 under load, but at around 3200 steam will start to be seen at the exhaust. It gets more pronounced the higher the RPMs go from there.

I was originally concerned but I checked with Andrew and he said this is normal. He said he often witnesses this himself when he is testing new Rangers. As long as there is plenty of water coming out of the exhaust he said the impeller is working and it was probably OK.

When I researched this, I also found references to much older 3ym30's that had a heat exchanger warranty issue that caused this as well. A number of sailboaters reported it. But I doubt yours is that vintage.

http://www.cruisersforum.com/forums/f54/yanmar-3ym30-overheating-4576.html

dave

Hi Dave,

Welcome to the mini-Ranger family. Last week, three teenage girls paddled by Kolo Iki and told me how much they liked the boat. I figure that if you can pass the teenage girl approval test, your boat must be pretty cool 🙂 I was responding to Bob H. when your post popped up. Mahalo for the confirmation, since both you and Gene and also Andrew have reported seeing the same "white smoke" while underway, that helps my warm fuzzy quotient considerably. The engine runs like a top and other than the lower than spec max RPM underway and the visible steam at increasing RPMs, I have not had any concerns.

I am curious to know how your boat is cranking out so many RPMs however. In a fairly calm sea state, my GPS speed is about six knots (give or take a knot) at 2400-2500 RPM. Running up to max RPM I have seen eight to nine knots, but it is not a comfortable (noise wise) or efficient way to run the motor. Although I try to remember to do that for five minutes when coming back in from offshore. What kind of speeds are you seeing at WOT?

Your attached Yanmar link was interesting, I went out to Kolo Iki after reading it to check the data plate (2007 tug) and the number stamped was EO 7704, which I am thinking might indicate that it was the 7704 engine built in that series. Thanks again for your help, I look forward to your future posts.

Aloha,

Rick

 

[K7MXE]

Aloha

You know the factory did do a prop change about the time the R21ec came out. They sent the owner of EC number one a new prop. I remember checking to see if mine needed a upgrade and remember this much. If the prop is wavy like a ripple potato chip then its the correct prop and if smooth it is the older prop. That would show the difference in max rpm under load. I did a check on time with the gps and my boat with perfect condions would do 10.0 kts and nothing more on a lake at 1100 feet above sea level. One each fat boy on the helm too. I never go that fast at all but hit it one time leaving a lock and got it to 19kts, glad I was going downhill that day as would have been rather slow uphill.
The pitch will be marked on the prop and you could check with the factory as to it being correct.
I just thought of a new thread about the price of hand held flares. They were fresh but now cost 34 dollars for three of them at Cabelas sporting goods store. They that much out in the middle of the Pacific? Bob H

 

[Rick & Karen]

Aloha

You know the factory did do a prop change about the time the R21ec came out. They sent the owner of EC number one a new prop. I remember checking to see if mine needed a upgrade and remember this much. If the prop is wavy like a ripple potato chip then its the correct prop and if smooth it is the older prop. That would show the difference in max rpm under load. I did a check on time with the gps and my boat with perfect condions would do 10.0 kts and nothing more on a lake at 1100 feet above sea level. One each fat boy on the helm too. I never go that fast at all but hit it one time leaving a lock and got it to 19kts, glad I was going downhill that day as would have been rather slow uphill.
The pitch will be marked on the prop and you could check with the factory as to it being correct.
I just thought of a new thread about the price of hand held flares. They were fresh but now cost 34 dollars for three of them at Cabelas sporting goods store. They that much out in the middle of the Pacific?

Hi Bob,

I will take a look at my prop next time I get in the water (just out of curiosity), maybe later today. As for the flares, I had to replace all signaling devices when I bought the boat due to expiration dates. I went to West Marine and purchased the Orion soft storage kit featuring the 12 gauge flare pistol and flares with both types of hand held flares. The normal price is $119.95, but as I recall, it was on sale and with the new boater discount I paid about $95.

As for my personal best max speed, I have seen twelve knots in the channel outside our marina with a little help from a breaking wave rushing up from behind. Basically I was surfing with a 21 foot board.

Aloha,

Rick

 

[dloop]

Last week, three teenage girls paddled by Kolo Iki and told me how much they liked the boat.

Hey Rick,

Passing the teenager test is very important!! Maybe this means they will hold their value longer. 🙂

Here is a video I took of the steam coming out of my exhaust. I took this with my cell phone so the quality is not the best. Hopefully this link indirection will work. I wasn't able to figure out how to embed a flickr video link here directly.

http://21ecsteam.blogspot.com/2010/01/blog-post.html

dave