92 Mercury v6 air in outlet hose

[garybutler767]

I have rebuilt my engine. First time ever did something like this. When finished I took it to the marina and had them set the timing and check the oil pump. The oil pump did need replaced.Since I discovered that the origin of the problem was the oil pump, I educated myself as much as I could about the oil pump systems. Everything I read stated that the oil pump must be bleeded from the inlet hose going to the oil pump and also the outlet hose must be bled as well. I still have air in the outlet hose and cannot seem to get it out. I took it back to the marina and expressed this concern. They said that you will always have some air in the outlet hose because it drips like an IV would. I wanted a second opinion and other marinas said that there should be no air in the outlet hose. I searched the internet and was thinking that the check valve on the outlet hose could cause air. I inspected my motor and gas does not get into the outlet hose so it is closed off. I need to know if this is normal? I went through alot of reading and rebuilding to get my motor back to good running shape. I dont want to have a lean mixture due to air in my outlet hose cause the same concerns of scoring my cylinder wall. If anyone can give me some advise on how this outlet hose in relation to air seen in the hose works, that would be great. I am not completely satisfied yet or feel completely safe.

 

[gss036]

Re: 92 Mercury v6 air in outlet hose

I just reread my OEM manual for my 1989 200 hp Merc which should be the same I would think. While it does not specifically say there should not be air in the it does say that if there is any bubbles, they should bleed them out of the system. So, I would think that air is not a good thing. The OEM manual gives good instructions over several pages on how to check the system and how to bleed the system. It also tell you how to check oil pump volume flow.
I would suspect that you have an OEM manual, my instructions are in sec 8.
It also specifially says you should be running 50-1 mix plus the regular mix during the 1st 30 hours of operation.
Hope this helps you out.

 

[garybutler767]

Re: 92 Mercury v6 air in outlet hose

Thanks for the reply. It is similar to what I read as well. That is why I didnt feel comfortable with what the Marina mechanic told me. I am currently running a 50:1 mixture. One thing I am curious. Can you or anyone out there who has a V6 Mercury and has been running this summer without any concerns check your oil outlet hose and let me know if it is full of oil or does it have any air in the line and maybe just 1/3 oil settled at the bottom of the next the check valve?

 

[P51D]

Re: 92 Mercury v6 air in outlet hose

Gary - if you tell me where to look, I'll check my Merc V6 next time I'm at the boat.

 

[garybutler767]

Re: 92 Mercury v6 air in outlet hose

Follow the oil line from your oil tank on the motor itself. It should lead you to the oil pump. Next there is a line or (clear hose) that leads to the fuel line near the bottom of your powerhead near the controls for shifting. This particular clear hose is called an outlet hose (Hose going out of your oil pump). This particular website path give a great illustration and talks about how to bleed the air in outlet if there is air bubbles but does not specifically say no air is allowed. Look at the Bleed the air portion which will show you the outlet hose.

http://continuouswave.com/whaler/reference/mercuryOilInjection.html

Anyway, the marina says air is okay in the outlet hose but this article implies different. If yours has air in the outlet hose and never have a problem, then this may validate what the marina told me.

thank you for your response.

 

[gss036]

Re: 92 Mercury v6 air in outlet hose

I would not think it matters if there is a slight amount of air, but at the same time, I would think that if you opened the bleed screw that the air would bleed out, especially if the engine is not running. The oil in the line is forced into the "T" where it is blended w/gas and then to the carbs. If the system is tight I would not think the air would remain in the line unless there is a small vaccum leak and keeps sucking in a small amout of air. Interesting situation.

 

[garybutler767]

Re: 92 Mercury v6 air in outlet hose

I was told that the bleed screw allow air to be purged from the inlet hose going into the oil pump as well as any air trapped in the pump itself. Your comment on the vacuum makes me think that this is a leak somewhere. I think I will go ahead and replace the check valve on the outlet hose to the fuel line. If somehow that area is effecting the vacuum that would make sense. Your may be right that some air should be allowed. I need to find someone with the same motor and inspect that motor for the same condition. I should come across one similar soon. Thank you for your reply's.

 

[gss036]

Re: 92 Mercury v6 air in outlet hose

I wish I could help more, I won't be putting my boat into the water until 1st of July.
Another word of caution, while you are looking and messing with those clear oil lines, make sure they are not brittle or stiff. I replaced mine last summer as a precaution after reading a thread about the lines being brittle and cracked. They guy toasted his engine. If the feed line does leak or come loose, it will not send any type of signal to the oil alarm system and you just keep runnig w/o oil until there is a seizure for lack of oil. Mercury lists 2 different sizes of oil lines for my engine and I bought both, ended up w/enough hose to change out again if ever needed. I asked about them sending extra lengths and parts guy said it kind of ageneric thing since different motors take different lengths. Not that much $$, maybe $20 +s&h.
Good luck

 

[garybutler767]

Re: 92 Mercury v6 air in outlet hose

You nailed it. That is exactly why I had to rebuild my engine. My oil line broke because it became brittle and I did not find out til it was too late. That is why I have focused in on that area and read as much as I could on how this oil system works before I go through that again.I am making sure everything functions correctly. It runs nice now but some mechanics have different ideas about air still in this see through hose. Some say okay and some say absolutely no air allowed. They have me a little confused and nervous about running around and not having another problem.

 

[P51D]

Re: 92 Mercury v6 air in outlet hose

garybutler767 - I was finally able to get to the boat to check the outlet hose. I saw no air bubbles. I hope this helps answer your question.

 

[hkeiner]

Re: 92 Mercury v6 air in outlet hose

Hi,

If it helps any, I checked the clear oil line on my 1996 150HP Mercury motor and did not see any air bubbles.

 

[garybutler767]

Re: 92 Mercury v6 air in outlet hose

Thank you for your help. I was very curious if any one else could see air in that hose.

 

[garybutler767]

Re: 92 Mercury v6 air in outlet hose

All,

Thanks to those who responded. I figured out what the problem was. The metal pc (check valve) connecting the oil hose to the gas line was bad. It cost $11 to replace and it now works fine. The oil kept leaking out into the gas line when stored and engine off. I ran the engine for a while this week-end, let it sit and no more air.