Logo
FULL SITE MENU

So...... oil.

M

metal-chicken

Regular Contributor
I was reading an old thread where 25w-40 was suggested rather than 10w-30 as it would 'cling' better and thus give more protection to an engine that's been sat for a number of months.

It's probably not warm enough in the UK to go with 25w-40 so I use 10w-40 semi-synthetic in my 225. Is it advisable to turn the engine over without the kill cord in to circulate some oil to the bearings before starting proper after a long period of non-running?

I'm struggling to believe that bearings etc. become 'dry' after a week or two of inactivity, in which case the viscosity of the 25w-40 really only potentially helps on that one first start up of the season.
 
Last edited:
In your colder waters I would be inclined to stick with factory recommendation of 10W30 although 10W40 would also work fine.
 
I agree with NOT changing viscosity of oil used but spinning the engine with the fuel shut off and ignition dead would be a way to
"pre-lube" the bearings after an extended shut down. A too high viscosity would actually prevent the oil from flowing properly and could, theoretically, starve the bearings of oil on cold start.

However, one, or even two, weeks of inaction wouldn't be an extended period of time in my opinion.

Good luck.
 
Just one thing jgmo, I have known 75s and 90s to get an airlock in the oil pump so that the only way to reprime is to give a quick burst of throttle or loosen the oil filter. With the oil pump sitting above the oil level I think instant start up is imperative. I know Suzukis are programmed to rev up to about 2000 rpm at start up and it is for this reason, to ensure the pump primes quickly.
 
Back to the oil weight. I live on the lower Potomac near the Chesapeake bay. Here, a lot of recreational boaters fire up their boats in May and put them to bed in September. Under that scenario, quite a few experienced thrust washer failure, which is usually catastrophic for the engine. The local mechanics and dealers switched over to the Merc 25W-40 FC-W oil at the fall pull out season and reported that the incidence of thrust bearing failures dramatically dropped.

Personally, I do not ever leave my engine sit anywhere near that long without being run. However, at about 1500 hours, I did switch from 10W-30 (as Honda recommends) to 25W-40. After an additional 600+ hours, I've experienced no obvious problems. Thrust washer play remains within specs.

I agree with Jimmy and Ian that in colder waters or with a new engine under warranty, it's probably best to stick with the 10W-30 or 10W-40. However, as a cautionary procedure, I would try to make sure my engine was run more frequently and not allowed to sit up for many months at a time. This is especially true with an older engine where the thrust washer may already have some wear on it.
 
[ quote]However, as a cautionary procedure, I would try to make sure my engine was run more frequently and not allowed to sit up for many months at a time.[/quote]So with this in mind seeing as I've got a 750 litre tank of water sat under my [tilted up] engine it would be easy for me to drop it down every 4 weeks over the winter and to give it a run.
Does this make sense? And if so what sort of time should I be running the engine for 10-15 mins?
 
Install a " prelube system "-------That would circulate oil through the bearings without the crankshaft turning in the " dry " bearings.
 
Metal-chicken,

That sounds like a good plan to me. 15 to 20 minutes to get everything warmed up well. That has the added benefit of keeping the water pump and pressure relief valves in good shape.

Racerone - never seen or heard of a prelube system installed on an outboard - only big diesel engines. Seems like it would take a lot of pressure to force oil into the crank and cam bearings. Can you expand on that idea?
 
??----Pressure?-----How much pressure and why does it put out that pressure with the oil pump on the motor ?-----It would not take more than 10 psi to supply oil to main bearings.--------Now if you wanted to raise a 100 ton steam turbine rotor clear off a babbitt bearing you would need a lot of square inches and high oil pressure !!
 
Well, OK. You're obviously more knowledgeable than I am on the subject. Just never seen one on an outboard before. How would you hook it up? Seems like you would need an external oil sump and a pressurized feed into the oil pan.
 
?---Yes you would need an oil pump.----Supply to that oil pump.----Supply to an oil gallery ( with a check valve ) on the motor.-----The OP is concerned about wear to the bearings on start-up.----He might be interested / has the budget to install such a system.
 
This all seems very extreme, if you're paranoid about bearing metal to metal issues would it not be easier to use one of those excellent engine protection additives and run it through before storage time and then drain and refill with normal oil in the new season.
 
CHawk 25 DLX, I live in Chesapeake VA. and this was my first time storing my boat (dry storage) is there any special steps to take prior to starting my BF200 for the first time this season?
 
DABUTZ - I'm not the best person to give advice on that. I don't store my boat anymore. I just jack it up on the lift, then every 4 or 5 weeks drop it in the water, run it for 30 to 45 minutes. Then flush it really good, tilt the motor all the way in, make sure the flush hose is completely drained, then jack it back up on the lift. I don't even remove the batteries since it's never gotten cold enough in this area to damage them. Before storing, use a good fuel stabilizer, like Marine Sta-bil in the fuel.

As a minimum most folks would change out the oil & filter before storage. Also, drain the VST. If any fuel filters need to be changed out, it's a good time to do that before storage.

I think some folks might recommend fogging the cylinders before storage it it's going to be a long time before its run again.
 
Back
Top