JustUs2":2kfyd49l said:
Hello
On my 2010 R21EC at 5 knots the boat runs great no problems, but when i put the throttle all the way down I get white to white/gray smoke coming from my exhaust. The boat still runs fine but I am concerned about the smoke. Any ideas.
Hello JU,
What are your boat's WOT RPMs? That's not really related to the smoke, just curoius how close to 3500 you get.
Whitish smoke is difficult to discern from steam at WOT as the engine is probably as hot as it will get (when operating properly with adequate cooling water flow), so some steam in the exhaust is not abnormal. Whitish smoke can be unburned fuel as well....google "smoking diesel exhaust" and you will see there are a number of causes of dark, white, and even blue smoke.
If your engine operates properly across it's rpm range, does not consume crankcase oil, has no fuel or oil leaks, "sounds OK", and achieves appropriate fuel economy (0.5-0.6 gal/hr OR 10-12 mpg) then your Yanmar engine is probably OK.
Using an inexpensive infrared temp gun like this
start keeping track of engine temps in your boat's log book. The Active Captain people describe using a system whereby they put a little dot of red paint at several locations in their engine room...like the oil filter, exhaust elbow, muffler, etc. Then they record the temps in their log book. After a few years, they say, they quit recording the temps because they KNEW the normal range for each location (it's a KEY principle that they measure the temps at the SAME locations, hence the dot of paint to mark the spot). Anyway, start noting the temps of 2 or 3 spots on your engine/exhaust sytem. The IR Temp guns are cheap (like $25 or less; Harbor Freight or similar is fine - of course you can spend more if you wish - FLUKE is top of line) and they make great cat or dog toys (chase the red laser dot) of you get bored.
dave
