1993 Mercruiser 350 Ski Magnum carbed oil type

[Rugglesworth]

I'm sure this has been beaten to death over the years but I haven't seen a consensus. New boat to me. only had it out once and now waiting for a prop replacement. I'll be using the boat to mostly wakeboard and trying to surf it. Lots of constant rpms and weighted down with ballast bags. So should I stick with 20w40 quicksilver synthetic or is there a better oil to use these days? Also what's the best oil filter to use?

 

[Scott06]

I'm sure this has been beaten to death over the years but I haven't seen a consensus. New boat to me. only had it out once and now waiting for a prop replacement. I'll be using the boat to mostly wakeboard and trying to surf it. Lots of constant rpms and weighted down with ballast bags. So should I stick with 20w40 quicksilver synthetic or is there a better oil to use these days? Also what's the best oil filter to use?

Ask two guys what oil to use you will get 3 answers. ....

The quicksilver sythetic or not is fine. I run Mobil 1 15w-50. A lot of guys will Rotella T4 15w 40. Wix or baldwin filters get good recommendations. Napa used to be supplied by wix.

Dont over think it. Use a weight such that you keep 10 psi of oil pressure for every 1000 rpm of engine speed (50 psi at 5000 rpm when engine is hot). More importantly check the level daily as we've seen a few folks here loose oil pressure underway due to leaks.

 

[Rugglesworth]

Ask two guys what oil to use you will get 3 answers. ....

The quicksilver sythetic or not is fine. I run Mobil 1 15w-50. A lot of guys will Rotella T4 15w 40. Wix or baldwin filters get good recommendations. Napa used to be supplied by wix.

Dont over think it. Use a weight such that you keep 10 psi of oil pressure for every 1000 rpm of engine speed (50 psi at 5000 rpm when engine is hot). More importantly check the level daily as we've seen a few folks here loose oil pressure underway due to leaks.

I am a goof

I'll check out the Rotella and quicksilver. It's only going to run in warm weather and will be used to skiing and tubing as well.

 

[Scott06]

I do not help Wake Boaters.

 

[Scott06]

Wake boaters are useless. They attack anyone who does not like their dangerous wakes. Grow up goofy people.

You don’t even know this guy and you are attacking him. Not every one who wakeboards or surfs is an ahole. He may be an ahole in training, you know working he may be working up to it….
just like not everyone on iboat is as much of an ahole as you are acting like.

bottom line if you dont have anything useful to say ( most of your posts) why don’t you not say it.

 

[Mc Tool]

I do not help Wake Boaters.

Ha ha , yeah ,I was waiting for that

 

[Bt Doctur]

Rotella15 w-40

 

[flashback]

ithe rotella has a high zinc content which is good for the flat tappets.

 

[Scott Danforth]

on a flat-tappet motor, Rotella T4 15W-40 diesel

 

[Chris1956]

Gee, what kind of oil is specified for your motor? I will bet it is FC-W oil. FC-W oil is specifically designed for sterndrive and 4 cycle OB motors. Why not use that?

 

[Lou C]

Pick one, run a season and do an oil analysis that will tell you if it's good enough for your use.

 

[Bt Doctur]

on a flat-tappet motor, Rotella T4 15W-40 diesel

with high zinc for flat tappets,
I see better oil pressure and lower temps using it .

 

[Rugglesworth]

You don’t even know this guy and you are attacking him. Not every one who wakeboards or surfs is an ahole. He may be an ahole in training, you know working he may be working up to it….
just like not everyone on iboat is as much of an ahole as you are acting like.

bottom line if you don't have anything useful to say ( most of your posts) why don’t you not say it.

First of all, thanks for that. My family has had a cabin on a lake for over 100 years and I respect everyone. I only do watersports in bays that don't have any docks, cabins. Secondly, this is my first year with a ski boat and so my boys want to try skiing. Thirdly, if you know anything about direct drive boats, the wake is F all (meant for slalom) and that's where the ballasts come in. Thirdly, I/O's make a lot of wake, (deeper v hull etc.) probably the same amount as my ski boat WITH ballast so maybe people on here should think before throwing everyone into the same category. Finally, the guy that says gee what kind of oil did your boat call for, I was asking if there had been something that has changed since 1993 and also due to the fact that I am using it differently than designed may change what oil I want. I already explained I knew what the manual calls for.

To everyone that actually gave helpful advice I appreciate you.

 

[Scott06]

First of all, thanks for that. My family has had a cabin on a lake for over 100 years and I respect everyone. I only do watersports in bays that don't have any docks, cabins. Secondly, this is my first year with a ski boat and so my boys want to try skiing. Thirdly, if you know anything about direct drive boats, the wake is F all (meant for slalom) and that's where the ballasts come in. Thirdly, I/O's make a lot of wake, (deeper v hull etc.) probably the same amount as my ski boat WITH ballast so maybe people on here should think before throwing everyone into the same category. Finally, the guy that says gee what kind of oil did your boat call for, I was asking if there had been something that has changed since 1993 and also due to the fact that I am using it differently than designed may change what oil I want. I already explained I knew what the manual calls for.

To everyone that actually gave helpful advice I appreciate you.

Like you life long lake boater, some fishing, some water sports... always skied behind what ever we or our neighbors had (Typically underpowered IO bowriders).

Probably 10 years ago bought my daughters a wakeboard, and they really took to it, especially our youngest. Of course this lead to better boards, better skis, and put a tower on the current IO bowrider. Didnt do it to say look at me (as cyclops wrote in a different post on same subject) but because at 52 and being a big guy it is just plain easier to get out of the water...

I'd love to try surfing but cant rationalize the $ for something that we can only use 3 months a year. Personally im interested to see if you can press and direct drive into other service and run what you brung.

As for the oil use any 15-40 or 50 wt , a decent filter, change it annually and the engine will outlast the boat.

 

[Rugglesworth]

Like you life long lake boater, some fishing, some water sports... always skied behind what ever we or our neighbors had (Typically underpowered IO bowriders).

Probably 10 years ago bought my daughters a wakeboard, and they really took to it, especially our youngest. Of course this lead to better boards, better skis, and put a tower on the current IO bowrider. Didnt do it to say look at me (as cyclops wrote in a different post on same subject) but because at 52 and being a big guy it is just plain easier to get out of the water...

I'd love to try surfing but cant rationalize the $ for something that we can only use 3 months a year. Personally im interested to see if you can press and direct drive into other service and run what you brung.

As for the oil use any 15-40 or 50 wt , a decent filter, change it annually and the engine will outlast the boat.

I hear you I'm 48. I will report back regarding if I can get it to surf or not when I get back. I am going to make a couple wake shapers as well. BTW I ended up going with Pennzoil Marine Plus 20w40

 

[cyclops222]

Our best Wake boat is a 48' cabin cruiser. It can make a double wake no problem. Plus it is great while others are waiting to Wake. We wake in a dead end area. With no houses or boats tied to docks. Food, drink, warmth and conversation. We have 2 jet boats to pick up downers. Cruiser only stops to transfer riders.
Life is Good.

 

[Scott06]

I hear you I'm 48. I will report back regarding if I can get it to surf or not when I get back. I am going to make a couple wake shapers as well. BTW I ended up going with Pennzoil Marine Plus 20w40

Yeah there are some good sites out there and you tubes on direct drive surfing.
on the oil I have used everything from marine specific 25-40 , Walmart super tech, Mobil one and rotella.… Penns oil is a great choice, what ever is locally available. The only perceptible difference I have seen is the Mobil 1 and the synthetic blend and full synthetic mercury products seem to resist shear and keep oil pressure higher on long hot higher rpm runs (4000-5000 rpm) for longer periods of time. other than that dont over think it

 

[Chris1956]

Automotive multivis oil is not recommended for sterndrive or OB boats. It does not have the warm viscosity to protect the engine under the high loads of water cooled, 4 cycle, marine engines. I do not know if the diesel oils protect or not.

Now I have never run auto oil in my sterndrive, and then analyzed the failure, so I could determine what failed......

 

[Scott06]

Automotive multivis oil is not recommended for sterndrive or OB boats. It does not have the warm viscosity to protect the engine under the high loads of water cooled, 4 cycle, marine engines. I do not know if the diesel oils protect or not.

Now I have never run auto oil in my sterndrive, and then analyzed the failure, so I could determine what failed......

I have for years (15-40 and 20-50) no failure at all. diesels have a similar load to boats, in fact when I repowered a new to me boat in 2016 Michigan Motorz required rotella T4 for break in and recommended it for use

 

[Chris1956]

Scott, Is your engine made by Michigan Motors?

Now my knowledge is dated, but my MerCruiser called for SAE-30 or SAE-40 or the Quicksilver 25W-40. I have seen newer four cycle marine motors that specified an FC-W oil, but never diesel motor oil.

Run what you want, but please update us on the failure cause.