Help - white smoke

[imjus4u2nv]

Brought the boat out today, and when it started it smoked much more (huge cloud of smoke) then usual, white smoke that lingered. Something is off.
Even after I started driving it was still smoking more the usual but never overheated (she ran normal but didnt open it up for more then a minute). Pictir of smoke os after it was warmed up for a while. Pulled plugs, plugs on the left were very oily (too oily) while the ones on the right (v6) were dry/blackish (not sure if this is normal)(have picture of the dry one below).
I recently put new plugs (same model/type) and new thermostats in - not sure if this could be it.
Maybe a stuck thermostat and running too cool to burn the oil (not sure if that makes sense or is possible)
Any tips/advice appreciated.

 

[Harpoon]

It could be a thermostat. Stuck open you could have fuel mix blowing by the rings. that may also explain why its only happening on 1/2 of the motor. Also I wonder if it may be stuck in "warm-up" mode. Perhaps a bad temp sensor?

 

[imjus4u2nv]

Many thanks.
Will def look into, think first step is to put the old thermostats back in then go from there, will also do a compression test when I get the tool this weekend. I really hope that is the case afraid of what else it could be.

 

[Fishtales]

could there be something in the fuel?

 

[imjus4u2nv]

could there be something in the fuel?

Thabks fishtales, good point (in my old grady, I always left the tank almost empty, but the previous owner of this one always kept full so I did whatever he did). I will try to run it off a 5 gallon can and see of that helps. Not sure though why there would be difference between port cylinders and starboard.
On the thermostats update, I tested the old one and they opened up at around 140-145 degrees, the new ones closer to 130 - I did notice one the new thermostats looked like it was out of alignment (eventually closed all the way - but see pic) and also took much longer to close then the other new thermostat. Wonder if one staying open much longer would make a difference. Like an idiot I dodnt keep track of which one came out of the port side (side with oily plug (see picture).
I pit the old thermostats back in and will test it tomorrow or Saturday.
Keep those ideas coming and I will keep updating.

 

[imjus4u2nv]

Thabks fishtales, good point (in my old grady, I always left the tank almost empty, but the previous owner of this one always kept full so I did whatever he did). I will try to run it off a 5 gallon can and see of that helps. Not sure though why there would be difference between port cylinders and starboard.
On the thermostats update, I tested the old one and they opened up at around 140-145 degrees, the new ones closer to 130 - I did notice one the new thermostats looked like it was out of alignment (eventually closed all the way - but see pic) and also took much longer to close then the other new thermostat. Wonder if one staying open much longer would make a difference. Like an idiot I dodnt keep track of which one came out of the port side (side with oily plug (see picture).
I pit the old thermostats back in and will test it tomorrow or Saturday.
Keep those ideas coming and I will keep updating.

It could be a thermostat. Stuck open you could have fuel mix blowing by the rings. that may also explain why its only happening on 1/2 of the motor. Also I wonder if it may be stuck in "warm-up" mode. Perhaps a bad temp sensor?

Maybe a stupid question but is a thermostat the same as a temp sensor?

 

[seasick]

If it started smoking right after starting, it isn't t-stats.
Are you sure the smoke was white and not blueish? Could you smell the smoke?Was this the first trip of the season?

If so, did you fog or put oil into the cylinders prior to storage? If so, let the motor run and burn off the oil. Next time, don't change the plugs until after starting the motor for the new season and burning off the residual oil

Excess oil usually burns grey to bluish. Excess gas mix will make black/dark smoke. White smoke is a sign of water in the combustion chambers.
I am not sure why one bank's plugs are wet and the other are dry. Are you sure the wet plugs are wet with oil and not excess fuel?
Too much oil often means that the Precision OIling system is out of wack and pumping too much oil but that should affect both banks.

A clogged O2 sensor will result in too much fuel but again that should be seen in both banks.

Using your hand or a contactless IR thermometer, monitor the temp of each head near the t-stats as the motor starts from cold and warms up. The temps should match on both sides. If they are different, one cold be too cool or one could be too warm. If your testing showed t-stats opened at 140 or so, all is OK as long as they also closed correctly as they cooled. Were the t-stats installed in the correct direction? On some motors it is possible to install backwards but I don't think that your motor is one of those.
Now for the bad news; If the smoke is steam, you have water in the combustion chambers and that can happen to one side only. Hopefully that is not the case.

 

[Fishtales]

I wouldn't panic. run them a while (an external fuel tank if you can) and see how it goes. if you are getting water in there, likely not going to do any more damage in the short run.

 

[imjus4u2nv]

If it started smoking right after starting, it isn't t-stats. THAT MAKES PERFECT SENSE, WAS WONDERING IF ISSUE COULD BE WHEN ENGINE IS HOT, THEN TURNED OFF LEAVING EXCESS FUEL IN THE CHAMBER - ON NEXT START BURNS IT OFF AND MAKES THE HUGE PLUME.
Are you sure the smoke was white and not blueish? Could you smell the smoke? IT SEEMED TO LINGER AND SMELLED SO MAYBE NOT STEAM. Was this the first trip of the season? IT WAS SECOND TRIP, BUT WAS MICH COLDER THIS TIME AND VERY HUMID (FOGGY) WHY MAY HAVE EFFECTED THINGS. LAST YEAR IT WOULD PUT UP A LITTLE SMOKE BUT AFTER THAT RUN FINE AND NOT SMOKE. POSSIBLY HUMIDTY AND TEMP FOR THE SMOKE I SAW AFTER SHE WARMED UP, BUT STILL NOT SURE ABOUT THIS:
SHE IS ALSO HARD TO START (ALWAYS HAS), WILL START THEN STALL RIGHT AWAY, THEN TAKES A FEW TRIES TO GET IT GOING (NEED TO GOVE SOME THROTTLE), RPMS WILL JUMP UP TO AROIND 1200 TO 1400 (SURGES) FOR A LITTLE UNTIL SHE WARMS UP THEN WILL RUN FINE AND IDLE AT AROUND 700.

If so, did you fog or put oil into the cylinders prior to storage? If so, let the motor run and burn off the oil. Next time, don't change the plugs until after starting the motor for the new season and burning off the residual oil
GREAT ADVICE AND I DO THE SAME, PICS OF THE PLUGS WERE THE NEW ONES WITH LESS THEN 4 HOURS ON THEM. RAN OLD PLUGS ON FIRST START AND SHE SMOKED THEN BUT ASSUMED BURNING TJE FOGGONG OIL SO WASNT TOO CONCERNED.

Excess oil usually burns grey to bluish. Excess gas mix will make black/dark smoke. White smoke is a sign of water in the combustion chambers.
I am not sure why one bank's plugs are wet and the other are dry. Are you sure the wet plugs are wet with oil and not excess fuel?
I AM NOT SURE, BUT PULLED PLIGS AGAIN AND THEY SEEM MORE EVEN THIS TIME AROUND, BUT STILL SEEM BLACKISH LM
Too much oil often means that the Precision OIling system is out of wack and pumping too much oil but that should affect both banks. MAKES SENSE

A clogged O2 sensor will result in too much fuel but again that should be seen in both banks.

Using your hand or a contactless IR thermometer, monitor the temp of each head near the t-stats as the motor starts from cold and warms up. BOTH SODES WARM TO THE TOUCH. The temps should match on both sides. If they are different, one cold be too cool or one could be too warm. If your testing showed t-stats opened at 140 or so, all is OK as long as they also closed correctly as they cooled. Were the t-stats installed in the correct direction? REPLACED WOTH OLD ONES TO BE SAFE AND ONLY ONE WAY IN. On some motors it is possible to install backwards but I don't think that your motor is one of those.
Now for the bad news; If the smoke is steam, you have water in the combustion chambers and that can happen to one side only. Hopefully that is not the case.

 

[imjus4u2nv]

Yesterday I warmed up the boat, big puff of smoke and let it warm up (same cold start problem as described above), checked compression amd all were in range but maybe a little low (from 96 to 104) but performance doesnt seek to be an issue (she gets my 208 up to almost 40mph and its only a 150hp).
Going to run off external tank tomorrow while in the water to eliminate fuel issues (should have been first step) and will post an update.
Thanks all!!!

 

[Fishtales]

ok. keep us posted and good luck.

 

[seasick]

I think you will be OK after you use it a bit. The motor will spew steam in cooler weather just like you breath does.. I forgot to ask if you treated the fuel before storing, Some stabilizers in higher doses may create smoke. I want to make sure that when you say the motor 'surges' to 1200-1400 you are not confusing surging with a fast idle. A cold motor (SX) will idle fast at about 1100 revs until it starts to warm up. If that is what is happening that good and tells you that the temperature sensor is working ( FYI, t-stat, temp sensor and temp switch are three different parts). Surging on the other hand is when the revs speed up and then drop quickly and usually repeats. That is not normal and most often signals a clogged/dirty VST screen or bad low pressure pumps. Since you boat runs well at speed, that is probably not the case.
The issue with cold stalls and low idle is common for that motor and I have it on mine. I have never been able to figure out what causes it and just got use to engaging the shift override and raising the throttle after starting for 30 seconds or so. The stalling is more frequent in colder temps but doesn't seem to be directly related to a temp sensor or throttle position sensor. It may be related to just old age, perhaps stiff reed valves like my knees, LP pumps, or whatever. I have had the issues for years and it isn't getting worse so I don't worry about it.
I would follow up on the wet plugs but not until a good run or two. All the storage stuff has to burn off and the motor has to run at normal operating temps for a while. Remember that a clogged/ defective O2 sensor ( or a clogged O2 thimble) will cause the motor to run very rich. There is a heater coil in the O2 sensor that heats it for it to work correctly. If that coil doesn't work, the gas mixture will be off until the heads warm up and warm up the O2 sensor. I don't encourage folks to futz around with the O2 sensor unless that know what they are doing. It is a very expensive part and it kind of easy to damage if handled or cleaned or tested incorrectly
As part of routine maintenance you should also check the adjustment and operation of the oiler linkage. If out of adjustment or broken/disconnected, the oil injection will run at the highest oil ratio and will eventually foul the plugs.
Enjoy your boating!

 

[imjus4u2nv]

I think you will be OK after you use it a bit. The motor will spew steam in cooler weather just like you breath does.. I forgot to ask if you treated the fuel before storing, Some stabilizers in higher doses may create smoke. I want to make sure that when you say the motor 'surges' to 1200-1400 you are not confusing surging with a fast idle. A cold motor (SX) will idle fast at about 1100 revs until it starts to warm up. If that is what is happening that good and tells you that the temperature sensor is working ( FYI, t-stat, temp sensor and temp switch are three different parts). Surging on the other hand is when the revs speed up and then drop quickly and usually repeats. That is not normal and most often signals a clogged/dirty VST screen or bad low pressure pumps. Since you boat runs well at speed, that is probably not the case.
The issue with cold stalls and low idle is common for that motor and I have it on mine. I have never been able to figure out what causes it and just got use to engaging the shift override and raising the throttle after starting for 30 seconds or so. The stalling is more frequent in colder temps but doesn't seem to be directly related to a temp sensor or throttle position sensor. It may be related to just old age, perhaps stiff reed valves like my knees, LP pumps, or whatever. I have had the issues for years and it isn't getting worse so I don't worry about it.
I would follow up on the wet plugs but not until a good run or two. All the storage stuff has to burn off and the motor has to run at normal operating temps for a while. Remember that a clogged/ defective O2 sensor ( or a clogged O2 thimble) will cause the motor to run very rich. There is a heater coil in the O2 sensor that heats it for it to work correctly. If that coil doesn't work, the gas mixture will be off until the heads warm up and warm up the O2 sensor. I don't encourage folks to futz around with the O2 sensor unless that know what they are doing. It is a very expensive part and it kind of easy to damage if handled or cleaned or tested incorrectly
As part of routine maintenance you should also check the adjustment and operation of the oiler linkage. If out of adjustment or broken/disconnected, the oil injection will run at the highest oil ratio and will eventually foul the plugs.
Enjoy your boating!

This is great info (my manual is Clymer manual number b785 and is terrible).
Just checked and no water in the water seperator, but you are correct I treated the fuel (always use ring free) and stabilizer in a heavy dose from what I remember. I will run it tomorrow (fluke/summer flounder) season opened so two birdswith one stone.
And once again your are correct, it does not surge (great explanation by the way, knees may be stiff but not your brain), it revs up high then goes down to idle so seems normal, does not jump up and down.
I will look at oil linkage but will not touch until run through this gas - not sure whether to run tank down as much as possible (not too low) or half way and fill to dilute. She jas a full tank so gonna drive a lot tomorrow and try to burn it down).
This site reminds me that there are still good people p)out there (taking time to help others), appreciate the reminder guys and will strive to do the same.

 

[seasick]

Good luck withe the motor and fishing
There are some disadvantages to maintaining a fullish tank. Personally, I don't winter store with a full tank. My theory being that if it goes bad or gets a lot of water in it, I now have to get rid of 80 gals of gas. I store with about 20 gallons of gas and never in 12 years have had an issue with condensation or water intrusion. The second downside of running with a full tank is the weight. An extra half tank of gas adds about 250 pounds to that boat and that is like carrying an extra adult person and a child. Even by yourself, you will notice a performance difference when running with a full tank. If your trips are longer than mine, you would want to gas up to a fuller level.
Less weight means better fuel mileage. No sense in hauling dead weight. My approach does mean more stops at the gas dock but mine are really close by and gassing up more often means fresher fuel.

 

[imjus4u2nv]

Good luck withe the motor and fishing
There are some disadvantages to maintaining a fullish tank. Personally, I don't winter store with a full tank. My theory being that if it goes bad or gets a lot of water in it, I now have to get rid of 80 gals of gas. I store with about 20 gallons of gas and never in 12 years have had an issue with condensation or water intrusion. The second downside of running with a full tank is the weight. An extra half tank of gas adds about 250 pounds to that boat and that is like carrying an extra adult person and a child. Even by yourself, you will notice a performance difference when running with a full tank. If your trips are longer than mine, you would want to gas up to a fuller level.
Less weight means better fuel mileage. No sense in hauling dead weight. My approach does mean more stops at the gas dock but mine are really close by and gassing up more often means fresher fuel.

I agree this os first year filling up and storing, and for 5 years never has issue woth old boat, was trying to just maintain the status quo and do whatever he did prior.
Will post update when I make any progress.

 

[Fishtales]

I agree this os first year filling up and storing, and for 5 years never has issue woth old boat, was trying to just maintain the status quo and do whatever he did prior.
Will post update when I make any progress.

Same here. Never more than 1/2 full. Full bottle of ring free and a fill up on the first run. Never had an issue in 20 years with GW/Yammies.

 

[imjus4u2nv]

Quick update - realized that I am launching from a new place, which requires a 15 minute no wake zone back to the dock. Hit me that maybe low idle for too long was leaving extra fuel or oil in the cylinders, causing smoke on the next startup. Last time out, I idled at tied at the dock at around 1500 rpms for a few minutes before cutting the engine. On next startup, much less smoke (almost normal amount). Will continue to burn gas down and dilute and report back, but think it maybe ok.

 

[seasick]

Could be but it shouldn't be.. Check the oil pump adjustment as mentioned.. I don't think there is too much gas in the cylinders but there could be too much oil in the gas. The oil is injected into the VST tank. Could be that by running the motor at a fast idle you are burning the oil rich mixture and replacing it with lower oil ratio fuel ( the lower ratio) . If the oil ratio is too 'rich' it will be so the next time you start the motor. At idle the ratio is about 100 to 1 and at wide open it approached 40 to 1. (gas to oil) So if the linkage is disconnected, the spring that pushes the pump lever moves to the max. At idle in theory you would be injecting 2 1/2 times the oil needed. It is fairly easy to do a visual check of the oil linkage and operation. Adjustment if needed is a bit trickier but not complicated.

 

[imjus4u2nv]

Could be but it shouldn't be.. Check the oil pump adjustment as mentioned.. I don't think there is too much gas in the cylinders but there could be too much oil in the gas. The oil is injected into the VST tank. Could be that by running the motor at a fast idle you are burning the oil rich mixture and replacing it with lower oil ratio fuel ( the lower ratio) . If the oil ratio is too 'rich' it will be so the next time you start the motor. At idle the ratio is about 100 to 1 and at wide open it approached 40 to 1. (gas to oil) So if the linkage is disconnected, the spring that pushes the pump lever moves to the max. At idle in theory you would be injecting 2 1/2 times the oil needed. It is fairly easy to do a visual check of the oil linkage and operation. Adjustment if needed is a bit trickier but not complicated.

I inspected and all looks good, it is a little wobbly but otherwise looks good. Read online to check the plastic sleeves to make sure no cracks, will do so tomorrow.

 

[RussGW270]

Eh, was gonna throw in my 2 cents, but these guys seem to have it all under wraps. spark plugs are the best indicator of an issue, imo... sandpaper and a feeler gauge and cleaning them up, then monitoring them can tell you if you have an issue in one or more cylinders. Helps tell you if it is one issue or the entire engine. Also, since you have them off, Harbor Freight has an inexpensive compression tester.. I mean.. may as well at that point.

Burning fuel is an indicator... even in an old engine, and not a huge deal, since you clearly are on top of it... heh.. I bet it will be easy peasy to get those running better and cleaner.

R