can the oil pump be bypassed?

jiffyboat

Petty Officer 2nd Class
Joined
Oct 4, 2009
Messages
114
hi, yesterday I got my boat in the river and after been cruising for some minutes I when back to idle and notice a knocking noise coming from the motor , went back home and checked the compression and in one bank is 100psi and the other 120psi, they where all 120 psi before, also noticed that the plugs where very dry , like if the motor is not getting oil...I have a 1997 130HP Johnson 90 degree with the VRO , and I would like to disconnect the oil pump and premix the gas , that I really preffer and I think is more secure, having two cylinder with 20psi low still is no that bad, because the motor still runs very strong...there is a way to do this ?..any help thanks
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: can the oil pump be bypassed?

Check out the Engine FAQs Forum for info on disconnecting VRO.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: can the oil pump be bypassed?

First, you don't have have a VRO, you have an OMS.

Second, the pumps are not selective as to cylinders, so a problem that affects only one cylinder is almost never a VRO/OMS problem.
 

jiffyboat

Petty Officer 2nd Class
Joined
Oct 4, 2009
Messages
114
Re: can the oil pump be bypassed?

I understand that point that the oil pump will feed the four carb at the same time ,I think it was matter of time that I didn't run the motor for a longer time and just two cylinder were partially affected if no, how to explain that the plugs were so dry and clean , like they were just running with plain fuel , the carbs were just rebuild with OMC kits, and why the knocking noise that was not there before taking it to the water , and I think it was lack of oil because I started it today morning for like 15-seconds and the noise was gone
 

w2much

Lieutenant
Joined
Jun 22, 2005
Messages
1,289
Re: can the oil pump be bypassed?

Noise was gone huh? No technical info here only an experience. On my bro inlaws boat against my advice and common sense to the wind he decided to cut through a large kelp patty instead of around it. The kelp clogged the water intakes and the motor knocked loud and stalled. I was certain he blew the engine. I cleared the kelp and after a few minutes to cool down the block the motor started back up.We let it run for a while got out of the kelp and headed in. Been running fine since. I would premix my fuel til you are certain about your oiling.Keep an eye on your oil reservoir and check for air leaks in your oil line.You may care to remove the heads to check for scoring.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: can the oil pump be bypassed?

Premix your fuel as well for a while and monitor the oil tank level. Your OMS would not cause a 1 bank fuel issue. It would be something in between.
 

jiffyboat

Petty Officer 2nd Class
Joined
Oct 4, 2009
Messages
114
Re: can the oil pump be bypassed?

thanks for all the info and ideas guys , I will try all of this and I will post the results lately
 

jiffyboat

Petty Officer 2nd Class
Joined
Oct 4, 2009
Messages
114
Re: can the oil pump be bypassed?

Ok today morning I opened the oil tank and pulled the oil filter , and it was super nasty , so much slush , that you won't believe me, I think this was all the problem and it was just matter of time to damage the other two cylinders also, probably at idle it was getting some oil, but no enough at high speed, I desired to cut the oil hose and plug the oil pump ,and unpluged the oil sensor, I will premix the oil and gas , and be relax in the water no thinking if the motor is getting or not the right amount of oil..
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: can the oil pump be bypassed?

Be sure to disconnect both harnesses and verify that the overheat signal still works.

Probably 13 years without changing the oil filter. I wonder how many others out there are like that?
 
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