Fuel and oil OMC 3.0 >

I just purchased an inboard, OMC 3.0 L. Can someone tell me the proper fuel and what type of oil to use? I am assuming that because it is basically a car engine that I would use standard oil, but I figure better safe than sorry. And that you do not mix the oil in fuel tank.

Re: Fuel and oil OMC 3.0 >

Any gas station pump fuel but premium is best to prevent spark knock (detonation). Oil - any brand SAE 30, straight 30 weight, I prefer Mobil or Pennzoil. No mix oil in fuel. You should also be concerned with lower unit oil / lube. You didn't mention what drive you have but if it's a cobra, look here:

Re: Fuel and oil OMC 3.0 >

Outstanding and it is a Cobra bottom end and thanks. Does anyone know where I can find a manual for a 1992 Forester and the OMC Cobra, same year?

Re: Fuel and oil OMC 3.0 >

What a coincidence! My boat is a Forester as well! I think that MFG lasted only two - three years. However, mine is 1990 w/4.3 liter motor. I will be searching for manual/s too, but for a tip, locate your model and serial numbers for the engine and drive. The drive was pretty easy (little aluminum tag) but I still haven't found my engine model. As stated before, it's a 1990 boat I bought new in the fall of '89. But I am fairly confident it is '89 motor because it has points. Right about '90 is when they switched to CDI ignitions and mine was a left over I guess. I selected this Forester at the time because all of the specs I researched, it had the most HP, least weight for the least $. 205HP - 2100 lbs, ~$12500. Anyway, once you know what motor / year is, should be able to pic up off Ebay. Or maybe one of the pros here will chime in with a source.

Re: Fuel and oil OMC 3.0 >

FSM link. 88 megs. NOt sure the year but my boats an 88' and this has helped me immensely. My Files

Re: Fuel and oil OMC 3.0 >

bonzoscott said:

What a coincidence! My boat is a Forester as well! I think that MFG lasted only two - three years. However, mine is 1990 w/4.3 liter motor. I will be searching for manual/s too, but for a tip, locate your model and serial numbers for the engine and drive. The drive was pretty easy (little aluminum tag) but I still haven't found my engine model. As stated before, it's a 1990 boat I bought new in the fall of '89. But I am fairly confident it is '89 motor because it has points. Right about '90 is when they switched to CDI ignitions and mine was a left over I guess. I selected this Forester at the time because all of the specs I researched, it had the most HP, least weight for the least $. 205HP - 2100 lbs, ~$12500. Anyway, once you know what motor / year is, should be able to pic up off Ebay. Or maybe one of the pros here will chime in with a source.

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Hi guys I am new to this forum but I as well have a 1992 Forrester Diva 1800 GT with a 3.0 cobra with cobra sterndrive... I am quite thankfull to finally run into someone else with this same manufacturer.. i love this boat and so does everyone else i come across.. such clean lines, they really are a beautiful boat.. I was beggining to wonder if there were any other forrester owners in this world.. The 3.0 cobra is a little light out of the hole but hummes along fine at speed.. I have trying to get a little better hole shot without changing the prop.. My preticulat model is the 3.0 ho and is rated at 140 hp with the holly 2barrel.. any tips or tricks..? i had the carb rebult last year which helped but she isnt quite there yet.. Thanx and again nice to meet fellow forresters..!!

Re: Fuel and oil OMC 3.0 >

I run a mixture of 87 & 89 octane. The 89 will help to avoid run on. Oil is SAE straight 30 like someone else posted. Stay away from multi weights such as 10w30.

Re: Fuel and oil OMC 3.0 >

Vertigo said:

Outstanding and it is a Cobra bottom end and thanks. Does anyone know where I can find a manual for a 1992 Forester and the OMC Cobra, same year?

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I found my manuel on ebay.. It is the factery manuel and is in very good shape.. the price wasnt bad either..

Re: Fuel and oil OMC 3.0 >

buy your manuel off iboats.com. Thats where i got mine, It was like 25 bucks came in 2 days.