Opinions???

[sweeper3]

I have a VF250 SHO, 2010. 400Hrs. This engine is making oil, fuel dilution i assume. When I change the oil, frequently, i use Yamaha full syn.( LUB-05W30-FC) , but I'm changing oil every 40 hours or so. Do any of the experts on here think it is necessary to use it, vs. the Normal 4M motor oi?? 05W30. Or stick with the extra lubricity of the Full Syn..??

Thanks in advance.

[boscoe99]

I see no benefit whatsoever of using Yamaha synthetic. Particularly if you are changing it every 40 hours or so.

I take that back somewhat. I see a benefit to Yamaha.

[sweeper3]

I see no benefit whatsoever of using Yamaha synthetic. Particularly if you are changing it every 40 hours or so.

I take that back somewhat. I see a benefit to Yamaha.

This is what I was thinking too:-)

But on the other hand, will natural oil breakdown easier or more completely the Syn. with fuel dilution? Humm need to put a call into the engineers \..

THanks for the opinion

[99yam40]

seems you need to be trying to fix the making oil

[boscoe99]

The engineers are all in Japan. Engineers sometimes can't even agree amongst themselves. Ask 10 engineers and you may very well get 12 opinions.

Has your motor always "made oil"? There are a number of issues known to contribute to this phenomenon. Lots of idling time, usage in cold water, being over propped, thermostats stuck open, leaking fuel pumps (does not apply to the SHO), injectors sticking open, carbon build up, rings not being seated, etc. Also, it is quite easy to over fill a four stroke outboard motor. Folks do it by mistake and erroneously think they have a making oil issue.

Again, this is just an opinion, but I would use regular dino oil and just change it as needed. If a problem can't be found with the motor and the oil dilution issue persists, I would just fill to the minimum oil line. If and when it rises to the maximum oil line I would change the oil.

[sweeper3]

seems you need to be trying to fix the making
oil

From what I've read. Some of them do it and some of them don't. I really dont want to dig into the power head. If it is easier to change oil often then that is what I'll do till it's time buy a new engine.

The engineers are all in Japan. Engineers sometimes can't even agree amongst themselves. Ask 10 engineers and you may very well get 12 opinions.

I am an engineer, electrical:-) And you are correct on this assessment.

Has your motor always "made oil"? There are a number of issues known to contribute to this phenomenon. Lots of idling time, usage in cold water, being over propped, thermostats stuck open, leaking fuel pumps (does not apply to the SHO), injectors sticking open, carbon build up, rings not being seated, etc. Also, it is quite easy to over fill a four stroke outboard motor. Folks do it by mistake and erroneously think they have a making oil issue.

Again, this is just an opinion, but I would use regular dino oil and just change it as needed. If a problem can't be found with the motor and the oil dilution issue persists, I would just fill to the minimum oil line. If and when it rises to the maximum oil line I would change the oil.

I didnt buy this engine new, but it had 75 hours on it. It has made oil since i've had it.. It takes around 40 hrs to raise the level from mid dip stick to full and when it does it reeks of gas. I regularly use Ring Free, and that seems to help (snake oil).. I suspect it could be over propped, since it cant get it to rev more than 5200 RPMs. I don't do a lot of *****ing, but i do have a little "No Wake" area to get out

My idea is to run it like I stole it and add multiple maintenance points. Keep an eye on it every day. It runs like a champ and gets acceptable MPG. I go 140 miles on 34 gallons.
So instead of working myself up, and contacting Yamaha. I just change the oil a lot. and trade after 600 hours..
The failure of the power head on these engines is related to the lack of lubrication from dlilution.. Several have blow PH's around here in Florida. But they never check the oil

Thanks for all the input.. Regular natural base stock oils for me now..

BTW this engine is a 2010, and it's out of warranty.. For once I should have bought the extended warranty.. Live and learn
I think the Syn oils are probably better, as it will provide better heat transfer.. But not if its a Qt. high do to gas.

[99yam40]

I am not the expert on this , but I would think a leak down test would show if leaking by rings due to carbon sticking rings.
If ring free helps maybe you need a shock treatment to clear out carbon in ring lands.
Over propped should be easy enough to find out by trying other props.
testing or replacing stats should deal with stat sticking open.

Sending injectors to have them tested/ cleaned should eliminate them.
what else am I missing ?

[sweeper3]

I am not the expert on this , but I would think a leak down test would show if leaking by rings due to carbon sticking rings.
If ring free helps maybe you need a shock treatment to clear out carbon in ring lands.
Over propped should be easy enough to find out by trying other props.
testing or replacing stats should deal with stat sticking open.

Sending injectors to have them tested/ cleaned should eliminate them.
what else am I missing ?

You know I thought about a leak down test, I need to have the boat pulled and checked since I don't have the tools here to do it myself.

Thanks for the suggestion

[rodbolt17]

and fix the WAY over propped issue.

never saw an oil related failure on a 4 stroke motor other than rusted oil pans that leaked the oil out.

the typical failure (rare) that I see is either corroded heads or thrust bearings.

that motor must be able to hit 6K anytime you wish.

[sweeper3]

and fix the WAY over propped issue.

never saw an oil related failure on a 4 stroke motor other than rusted oil pans that leaked the oil out.

the typical failure (rare) that I see is either corroded heads or thrust bearings.

that motor must be able to hit 6K anytime you wish.

Really? My boat never comes close to 6K.. It has a Powertech 22p, 4blade. 15.25" diameter

[99yam40]

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