A lot of Smoke and Oil in Exhaust??

[HS91_Mike]

I have a 1991 Johnson 175 OR. I had been making some hull repairs and the boat has been in the yard for about 2 months. The engine hasn't been cranked/ran in about 6 weeks. I installed a new Envirude Egnition Switch as well. This past weekend, I ran the engine on the bunny ears and it was smoking a lot more than usual. This motor will normally smoke heavier than others when starting, but then it will burn clean. When I revved up the engine, more and more heavy white smoke poured out, which has never happened before. The engine was running very rich. My neighbors love me!! Put the motor back to idle and it sputtered out. It would easily re-start and do the same sequence. The end result was a lot of black oil that came out of the exhaust and up ended up on the grass.

Is this an ignition problem? Could the primer function be stuck ON? Or are these symptons of a bad plug or sticking carbs?? Please Advise.

Mike

 

[steelespike]

Re: A lot of Smoke and Oil in Exhaust??

Did the smoke have that great burnt oil smell?
Did the white smoke hang around or did it dissipate fast?

 

[Will Bark]

Re: A lot of Smoke and Oil in Exhaust??

That motor is 21 yrs old, sounds like it may be time for a decarb. Good luck.

 

[emdsapmgr]

Re: A lot of Smoke and Oil in Exhaust??

Johnson made two types of 175's that year, the older 90 degree 175 crossflow and the newer 60-degree 175. Which model are you talking about?

 

[HS91_Mike]

Re: A lot of Smoke and Oil in Exhaust??

This is a 60 deg looper.

I may have to re-build carbs and replace plugs now, but the engine has been running great for the past year up til yesterday. The carbs were re-built about 18 months ago. Which I used to do every 90-120 days when using ethanol fuels. marine grade fuel + a separator, and I have had no carb/fuel problems since.

I think the that primer might be stuck open. You can shut that off manually by turning the little red switch counter-clockwise from vertical to horizontal, right?

It is definately oil-related smoke, not steam, that lingered around and fumigated my neighbors place. Also, the VRO was pulled about 2 years ago and I run 50:1 gas/oil mix in it.

If it is the primer, is that a simple pull and replace fix?

Mike

 

[emdsapmgr]

Re: A lot of Smoke and Oil in Exhaust??

The red lever must be in the "run" position for normal operation. That means it must be parallel to the length of the solenoid. The "service" position is 90 degrees from parallel. If you run it 90 degrees, you open the fuel system to outside air. Check all your fuel hose connections for a leak. Your engine will smoke more if you have any type of air leak in the fuel system. If the VRO pump tries to draw fuel, but gets a mixture of air/fuel, it will pulse faster to compensate. The faster pulsing will draw more oil in, as it tries to draw more fuel. The excess oil will burn and the engine will smoke more.

 

[kenmyfam]

Re: A lot of Smoke and Oil in Exhaust??

VRO pump is gone ????? yes ???
What pump (s) are you currently using ????

 

[HS91_Mike]

Re: A lot of Smoke and Oil in Exhaust??

The VRO is gone. There is no oil pump. I am pre-mixing gas and oil at a ratio of 50:1. I replaced the ignition switch (which was an aftermarket Sierra) with an OMC Envinrude Ignition 0508180. I misconnected the primer with another post. So when I initially turned the key nothing happened. Then, I pushed the key in to "prime" the engine and it started and it smoked a lot. So, I actually followed the diagram on the back of the switch and got the correct wires on the correct posts and everything, tach, fuel, alarms worked correctly, but the engine was still smoking heavily. I'm concerned that I may have shorted out or burned up the solenoid/primer when I mis-wired the ignition. The only change that has been made to the engine is this new ignition switch.

It is a Johnson 175 OR, 1997 60 deg looper (mistyped 1991 initial post) and they do smoke a little, especially when starting. Usually that subsides quickly and to expedite that, I can rev the engine a little and "burn" some of that old fuel/oil out of the carbs. This time, however, when I revved the engine, more and more oil/fuel smoked out of the exhaust and left a burnt black oil slick on the grass that was about 4' long. There is too much fuel/oil going into the carbs and that is not combusting and coming out in the exhaust. Trying to figure out why.

 

[Kingair]

Re: A lot of Smoke and Oil in Exhaust??

Wish I could help. I will be watching this thread as well, as I have posted about the same type of situation this morning on another thread. Althought I still have my VRO connected.

 

[Georgesalmon]

Re: A lot of Smoke and Oil in Exhaust??

You may just need to run your engine in the water on the boat. It might just clear up after a few min at WOT. I would certainly do that before spending any money.

 

[pecheux]

Re: A lot of Smoke and Oil in Exhaust??

This just happened to me with a much smaller 15 hp motor. Ran it in a barrel as winter storage last run and prep and it smoked like never before and smoked more when I increased trottle and this went on for 5 or 10 minutes. It had not been used for several months and I never run carbs empty. I am no mecanic but I like to experiment with any mecanical problems with my OB's. So I adjusted the card screw to a bit more than 1/8 turn leaner and ran it a fast idle. After a few minutes it started to run normaly and did so at any Rpm. Dont know why ??? but it worked. As someone else mentioned I would also give it a good WOT run prior to spending any more money. Just my 2 cents worth .. LOL