97 25hp Evinrude burning excessive oil/smoking

[scott324a]

I am having a problem with my outboard. I just bought a used boat and it came with a 97 25hp evinrude. I have used it every weekend for the past 6 weeks crabbing(6hrs per weekend). Mostly idling around, but I try to clean out the carbs occasionally by taking a spin on plane. The past 2 times out it has been smoking pretty bad (more than normal). The most recent trip(8/9/08) I burned an excessive amount of oil. It has the built in tank which I filled before leaving. I noticed the red indicator light (low oil) blinking while checking the traps. I filled the tank again about half way through the trip. Right now it is sitting a little above half. I burned about 3.5 gallons of gas the entire day. This should only require ~8 ounces of oil. I am not sure how much oil the built in resavoir holds, but it is signicantly more than 8 ounces. I estimate that I burned a little less than one whole resavoir of oil using only 3.5 gallons of gas. I also noticed a small problem which never occurred before. While trying to get on plane to return to the ramp the motor felt sluggish and stalled a couple of times. Previously to wrapping up for the day we shut the motor off to debait all of the traps(~20 minutes). I had to let it idle for a bit before being able to get on plane. This had not occurred before and I ran around about 5 times to check out other areas on Saturday. Any suggestions as to why I would be burning so much oil.

On a side note I am noticing a decent amount of oil draining from the prop while sitting in my garage. I read this is normal...

The motor has ~60 hrs according to the guy I bought it from and it sat for at least the entire year of 07 up to July of 08. It may have been longer as the registration on the boat had run out in 06.

Any help is appreciated.

Thanks

Scott

 

[scott324a]

Re: 97 25hp Evinrude burning excessive oil/smoking

I was planning on pulling the oil pump and checking it, but can't for the life of me figure out how you are supposed to get it out. It is stuck below the oil resavoir and I have no wrench that can squeeze in there. Anyone have any tips.

Also, I noticed it has no electrical or mechanical operation. It is fed by gas running through it. Is it a venturi type?

Thanks

Scott

 

[clanton]

Re: 97 25hp Evinrude burning excessive oil/smoking

If this is a 3 cylinder engine, remove the oiling system and premix 50-1 in fuel tank.

 

[scott324a]

Re: 97 25hp Evinrude burning excessive oil/smoking

Thanks for the response. Yes it is a 3 cylinder. I was planning on doing that as a test, but would like to understand what the problem is or could be.

Thanks

Scott

 

[clanton]

Re: 97 25hp Evinrude burning excessive oil/smoking

I would guess a check valve in the pump is bad. This engine has a history of oiling problems and pack failures. Suppose to be the answer to Suz and Yam 3 cylinders. Did not happen. If you premix, you will never have an oil related engine problem.

 

[scott324a]

Re: 97 25hp Evinrude burning excessive oil/smoking

Thanks for the response. The oil mixture never changes based on rpms? 50:1 is the ration throughout it's operating range??

If I bypass the oil pump do any alarms need to be silenced? The motor has the s.l.o.w. feature, but I believe that is just temperature based.

Is it as simple as premixing and bypassing the oil pump?

Thanks

Scott

 

[HighTrim]

Re: 97 25hp Evinrude burning excessive oil/smoking

I am not saying do not start pre mixing, but the OMS system that you have is a great system. Read the following links for some pertinent information. The FAQ will also have some reading for you.

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

If you do wish to start premixing, it is fairly easy to do. Let us know if you need instructions.

 

[scott324a]

Re: 97 25hp Evinrude burning excessive oil/smoking

Chris,

Thanks for the great link. That gives me a better understanding of what's going on. What I am looking for is reason for the excess oil use. I did notice that the tube in my gas tank had a crack in it so it may be sucking air as full is used. I will give it a good once over to test it out.

Are there any other reasons the motor would be using so much oil. I would prefer to keep the motor stock if possible.

Thanks

Scott

 

[kenmyfam]

Re: 97 25hp Evinrude burning excessive oil/smoking

I had no issue with my VRO until it quit pumping. That is when I moved to premix.