Yamaha EF2400IS Generator Engine Oil?

Submitted: Saturday, Mar 17, 2018 at 02:19
ThreadID: 136425 Views:6552 Replies:7 FollowUps:4
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Howdy all,

I've just purchased a used Yamaha EF2400IS and looking for a little help in the selection of the correct engine oil to do a oil change. I've had a look in the book and it recommends Yamalube 10w 40, though I was very interested in any suggestion of alternatives that others may be using and recommending.

I'm currently in Perth and while I can find Yamaha dealers in Perth, I can't find one that sell Generators or parts. While they do sell Yamalube Oil, everything is about motorbikes and the people behind the counter couldn't help me.

The book talks about 'mineral based' oil in the 10w 40, though what I've seen on the shelves seems to be semi synthetic or synthetic.

Any help appreciated,

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Reply By: RMD - Saturday, Mar 17, 2018 at 09:26

Saturday, Mar 17, 2018 at 09:26
G'day Greg
The 10 W means it is 10 viscosity when the oil is cold and the 40 means, that cold 10W grade doesn't thin down to more than 40 would thin to when hot.
Note: the 40 aspect will be far thinner when hot than 10W is cold.Therefore the engine is hot running on thin oil as they all do.

I have a Honda 2 and it specifies 30W but I run it on 10W40 Mobil 1.
Mobil 1 seems to seal the rings better on most engines and therefore less usage of sump contents. Sealing also means the oil stays cleaner for longer.

PS, although probably a bit unnecessary, I run my Honda 4stroke whipper snipper and Honda Motor mower on the same stuff. Rarely have to change oil because it is dirty.
AnswerID: 617622

Reply By: Hoyks - Saturday, Mar 17, 2018 at 09:29

Saturday, Mar 17, 2018 at 09:29
All the stuff in the bike shops will be synthetic or semi synthetic and designed to perform in a motor that is under a lot more stress in a wider range of environments, temperatures, rpm ranges and lean angles than a generator that just sits there, nice and level chugging away at a governed RPM.

I'd just go into an auto parts store and buy some mid priced 10W40 for petrol vehicles or stationary engines from a reputable manufacturer and use that.

As a bonus it will be less than 1/2 the price of the Yamalube so you can change it twice as often and still be ahead.

I use 10W40 diesel engine oil in my ride-on, generator and pressure washer and for years in the bike (push mower gets monograde). It works fine, meets the specification for petrol motors but has more detergents in it to keep carbon in suspension.
AnswerID: 617623

Follow Up By: RMD - Saturday, Mar 17, 2018 at 14:57

Saturday, Mar 17, 2018 at 14:57
I am absolutely sure that a bike lean hasn't got much to do with oil performance.
An aircooled small engine driving an alternator in a so called generator runs much hotter than a water cooled motorcycle engine does. Often Generator engines are pretty well maxxed out in load while delivering their designated output, bikes are not.
If I rode my bike near the stress level of a generator engine I wouldn't have a licence long before lunchtime.
I cannot see why a bike engine oil will not suit a generator engine as long as the specs are similar or same.

The amount of oil you use in a generator is a low volume and unless running all day everyday the relative cost of good quality oil for it is low.
FollowupID: 889346

Follow Up By: Hoyks - Saturday, Mar 17, 2018 at 15:21

Saturday, Mar 17, 2018 at 15:21
But bikes do have dry sumps, significantly higher redline and the ability to contaminate the oil with clutch fibers.

I didn't say bike oil wouldn't suit a generator, I said the price wasn't justified when you can get a cheaper oil that will do the job more than adequately.
FollowupID: 889347

Follow Up By: RMD - Sunday, Mar 18, 2018 at 12:16

Sunday, Mar 18, 2018 at 12:16
Some bikes "may" have dry sumps, nearly all don't, but that doesn't change anything regarding the oil. Unless you are riding the bike upside down for a period of time the oil supply is not affected by lean, braking or acceleration.
If a bike revs higher than a generator does, true, then good bike oil is probably better for it.
Bikes have oil filters, all the bikes I have had since 1970 all have fliters like a car engine does. My current bike does. Generators don't, so superior oil and not run of the mill, is better for them.

I like an oil which is better than adequate. Cheap insurance seeing there is not much oil quantity involved.
FollowupID: 889388

Reply By: Ron N - Saturday, Mar 17, 2018 at 14:20

Saturday, Mar 17, 2018 at 14:20
Greg & Julie - The Yamalube 10W-40 is a semi-synthetic oil formulated to meet the JASO MA oil standard.

The MA, MA1, MA2 and MB oil standards are set by the Japanese Automotive Standards Organization, so that oils can be produced with improved specifications for motorcycles - and the MA1 and MA2 oils are produced particularly for those machines with wet clutches, that have the clutch oil supply combined with the engine oil.

The MA is a lower-spec oil that is not designed or approved for use with wet clutches - but it is basically a straight engine oil designed for high-RPM air-cooled engines.

The MB standard is a lower spec again, for use in motorcycles where the clutch and gearbox use separate oil compartments from the engine.

Air-cooled engines operate at increased temperatures to water-cooled engines, and the oil in these engines has the task of assisting in cooling, as well as lubricating.

Naturally, it has to have additives that make the oil perform well at higher temperatures, than those encountered in water-cooled engines.

All you need for your Yamaha EF2400iS is any brand of oil that meets the JASO MA oil standard.

Penrite's 10W-40 is a recommended alternative to Yamalube 10W-40.
In the link below is an explanation of the JASO MA and MB standards.

If you click on the blue link ("Click here"), it leads to Penrites oil selection webpage, where you can select your model to find the correct Penrite oil.

Penrite Technical Bulletin

On the oil selection page, your menu selection needs to be ... > Power Saws, Brushcutters and Trimmers > Yamaha [Generators] > EF2400iS

Many other brands of oil will also meet the JASO MA oil standard, you just need to go to the oil manufacturers webpage and find their selection chart.

Yamaha have a store locator page - but you will find the Yamaha generator retail points usually only sell Yamaha generators as a sideline to their main business.

Yamaha generator store locator

The days of bricks-and-mortar shops dealing in only generators and pumps and small engines - and fixing same - are long gone.

Even my local mower shop has moved 3 times in the last 5 years, and downgraded his operations to a smaller setup each time.

Cheers, Ron.
AnswerID: 617630

Reply By: Member - McLaren3030 - Saturday, Mar 17, 2018 at 14:26

Saturday, Mar 17, 2018 at 14:26
Hi Greg & Judy,

Another vote for Mobil 1. Yes it is synthetic, but will not do your generator any harm, in fact as has already been stated, will actually improve the performance and reliability of your engine. The only downside is that it is pricey.

I ran Mobil 1 in my 1998 Petrol Landcruiser exclusively, and it had well over 300,000 kms on it and was still going strong when I traded up.

I also used Mobil 1 V Twin in my Harleys over the years. Again, this is a synthetic oil, but has been specifically designed for air cooled motors such as motorcycles & stationary air cooled petrol engines. In fact, Harley Davidson approached ExxonMobil to supply their Mobil 1 V Twin in Harley Davidson branded containers. ExxonMobil refused as the Mobil 1 V Twin is a proprietary blend.


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AnswerID: 617631

Reply By: Dean K3 - Saturday, Mar 17, 2018 at 18:25

Saturday, Mar 17, 2018 at 18:25
Go to any lawn mower shop SAE 30 will be sufficent not like a generator has to work in temp ranges like a automotive engine does.

Think the auto chains will also have it in a small 1 l container they use bugger all oil.

One thing to do is never fill it and leave fuel standing in tank this will go satle causing startign issues later on, and add a fuel additive (stabiliser) this will help assist slow down the degradation of the rubbers in the carburettor.

can of aerostart or start ya bastard is useful to have esp if you have dodgy shoulders like I have and pulling stregth isn;t very much

AnswerID: 617640

Follow Up By: RMD - Saturday, Mar 17, 2018 at 20:50

Saturday, Mar 17, 2018 at 20:50
Dean K3
Generators run far hotter and often in conditions worse than liquid cooled Petrol or Diesel engines do. The above mentioned because they are controlled in their coolant temp, a generator is not.

Apart from perhaps one “O”ring which is long lasting, there aren’t any rubbers as far as I have seen.

Do not under any circumstances use Aerostart rubbish on any engine. If everything is correct, a petrol engine will start easily. Even on a cold day if choke works properly.
The use of Aerostart causes extremely sudden and excessive cylinder pressures in both petrol and Diesel engines and hammers big ends, and squeezes bearing metal out sideways from the bearing shells, if fitted.
It bends con rods and cracks pistons and rings. I have seen a $30,000 engine destroyed by Aerostart. I have had to repair John Deere tractor engine where bearings disintegrated and con rods were bent after it’s use by road repair gangs.
FollowupID: 889354

Reply By: Member - Greg and Julie - Saturday, Mar 17, 2018 at 21:42

Saturday, Mar 17, 2018 at 21:42
Hi all,

Many thanks for your comments and suggestions; they’ve all been very informative and helpful.


AnswerID: 617648

Reply By: RMD - Sunday, Mar 18, 2018 at 16:55

Sunday, Mar 18, 2018 at 16:55
Greg & Julie.
Since you possibly don't know what servicing has been done on the generator, it is a good idea to run it on Mobil Delvac 10W40, it is a diesel engine oil and will cause no harm to the engine, but it will clean the inside of the engine of buildup, if there, and leave the innards clean when drained. Many petrol engine oils don't clean very well.
A couple of hours running with it will do the cleaning and then use a 10W40 of your choice, or better if you prefer.
AnswerID: 617677

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