I have read pretty much every post looking for a prob like the one im having.I cant find one so maybe its a simple one and im just tarted or its somthing crazy?I had a 150 merc blk max 1996,just thought it was done so I got a 02 150 merc saltwater with less than 100 hours,that is having the same prob.My oil res.in the boat fills with so much air pressure that the motor stalls and wont start untill you open it.The alarm only sounded one time.opened tank stopped.Maybe this has somthing to do with the problem i was using walmart 2 stroke oil.....just dont have a clue and dont like breaking down on the water any help would be greatly app...
The Crankcase Pressure One Way Check Valve is responsible for generating the air pressure in the oil injection system. It regulates the PSI level of pressure in the oil tank while the motor is running and releases this pressure soon after the motor is turned off. While there are two other valves on the oil injection system, the Crankcase Pressure One Way Check Valve is the only one that regulates pressure. If you have too much pressure in the system, then I would suspect this valve as the culprit.
While I generally prefer to confirm that a component is bad before replacing it on a hunch, there are no practical bench tests that you can perform on this valve to test it for proper operation. The symptom of having too much pressure in the oil tank is the best indicator of it's failure. This valve is easy to replace and not very expensive. I would suggest that you just go ahead and replace it to see if it solves the problem.
The below link contains a very long discussion on the potential problems that can result from a failed valve in the oil injection system. It might help too.
Now im wonderig why the same probs would be,with both motors.I took off the check valve.Screwed into motor with a screen in it?Do you think it could be the res on the boat or maybe the lines mixed up,or even the oil?but both check valves in both motors doing the same thing..not sure?
I have no idea as to what you mean by the above phrase and I am not sure you are actually swapping the Crankcase Pressure Check Valve or something else. I don't know about any screen. The Crankcase Pressure Check Valve screws into the crankase on the starboard side of the motor just below the starter. A hose runs from this valve directly to the remote oil tank.
Quote:
My oil res.in the boat fills with so much air pressure that the motor stalls and wont start untill you open it.
Swapping the valves between motors would have provided some confirmation, unless both valves have failed at the same time or you really do not have too much pressure in the system. Further, I don't know how too much pressure in the oil injection system would cause the motor to stall unless it is pushing so much oil into the carbs that the plugs can not fire. If so, I would have expected you to mention excessive smoke as another symptom.
Anyway, I suggest buying a new valve and installing it on the motor to definitively eliminate excessive pressure as the cause. If the problem does not go away, then it is time to troubleshoot for other possiblities. Just my thoughts...
__________________
1996 Mercury 150HP V6 carbed outboard motor and Maxum 1900XR bowrider boat
Just to confirm. Way too much oil pressure will stall the engine by flooding it with oil at idle. Continued pressure will force oil into the fuel system clear back to the gas tank.
I would guess the check valve under the starter is bad. Also be sure your hoses are right.
thanks for the help.this site is a great help and so are u guys for helpping. i replaced the crankcase valve and also the tee on the lines. there was so much oil in the motor i changed plugs and bled lines.ayway i think that did the trick? i guess there is supp.to be a little press in the remote tank..i hope anyway. after i run the motor turn it off the tank hisses a bit when i crack it. is this normal?
i guess there is supp.to be a little press in the remote tank..i hope anyway. after i run the motor turn it off the tank hisses a bit when i crack it. is this normal?
It is normal to have some pressure in the remote tank while the motor is running and for the pressure to remain in the tank a short while after the motor is turned off. It is also normal to hear a hiss when removing the cap on the remote tank right after the motor is turned off.
The question, of course, is how long after the motor is turned off does it stop being normal for the pressure to remain in the tank. There are no Mercury published specs on this, as far as I know. Based upon my own experience, if the pressure remains in the tank for longer than 15-30 minutes after motor shut down, then I would think that the valve is suspect. I have read of other people having "too much smoke problems" and finding pressure remaining in their remote tank for hours or days, which is clearly too long. I will not be using my boat for several weeks, so I can not do an actual time measurement on my own motor right now. Perhaps someone else on the forum may be able to do this and report the results.
__________________
1996 Mercury 150HP V6 carbed outboard motor and Maxum 1900XR bowrider boat
I changed the crank ckeck val which is the air press into remote tank right? . I changed the tee check val. which is oil to res tank on motor ? Thought that had prob fixed. Fired right up no smoke. Alittle press in the remote tank but nothing like before. Started up 2 hrs later fired right up.Happy love u guys, but then today was going out, until I checked remote tank to much press plus there was oil all the way into fuel line.Draned some fuel. opened tank top, pressed that enricher button finally started. Did u say there was a third check val somewhere? Also checked lines to remote tank made sure they didnt get rev somehow they were right. I am not sure but it seems like that tee, it does not bleed from the bottom even by blowing air threw it 100 psi. Its brand new so again any more help Ill keep trying every thing u guys say. I still have that cheaper oil in the remote but dont see how that could be doing all this.Also it has had the same problem with 2 different motors and the tee valve was used on bth so I thought for sure that was it.Once u told me its job.But now im lost again.
I changed the tee check val. which is oil to res tank on motor
You wrote kind of a long confusing narative and I don't know what the "tee check valve" is, but I'll try to answer what I understand.
The Crankcase Pressure One Way Check Valve is one of three check valves on the oil injection system. It is the only check valve that regulates the pressure in the sytem. If you have too much pressure in the system, it can only be caused by this check valve. However, there is another check valve that, if defective, can cause too much oil to flow into the fuel line after the motor is turned off. This is the check valve that is located in-line between the oil pump and the fuel pump. If this valve is stuck open, it will allow oil to drain/siphon from the reservoir tank into the fuel line while the motor is off. I replaced both valves on my motor when I had a "too much smoke" problem on my motor.
Some cheaper oils will smoke more than others, and all oils will smoke somewhat.
The below thread contains lots of information on how the oil injection system works.
Im confusing when I try and type thanks for trying to help me anyway....I read ur link I was talking about check valve A when I said tee.Now I understand that vavles job after reading what u wrote.I thought it was backwards cause it wasnot releving pressure. Its made to suck air if needed.Anyway thats new. So is the crankcase valve. Where is the third check vavle that I hope is my problem....Thanks again...
Just as a side note, I inquired about the massive smoking on my 135 and got the same good advice about the check valve. Just received the new checkvalve (not in the boat yet) and noticed that you can blow both ways through it with your mouth, although blowing through the side connected to the oil containers is much harder but does pass air. On my original check valve you could not blow back through it at all.
2 stroke oil problems mercury 150
Re: 2 stroke oil problems mercury 150
Linear Mode
