Best oil for Generator ????

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I was just given a brand new Coleman Powermate 5000 Generator,
from Home Depot. It has a Robin Subaru 10 hp OHC single cylinder engine (EX30D). I put in Castrol GTX 5w30 for the break in oil, and ran it for 45 minutes yesterday with no load. I will be using it primarily as a back up generator, so it will sit for long periods of time. Though I'll probably run it once a month or so. Should I stick with dino, or should I use a Synthetic. I thought the syn might be better, as it will sit for a while. And I also was wondering if I could use syn at the first oil change(20 Hours) or do I need to run dino longer for the break in?
I plan on doing the first oil change at 20 hours, and doing 100 hour/1 year oci's there after per the manual suggestions.
If I do go with syn, what should I use. I was thinking about PP 5w30, or M1 5w30. Thanks in advance for your advice.

Justin
 
10W30 of latest API service rating.

Yes, flush the oil (change it when warm) a few times to rid of any metal shavings and from that point onwards, any motor oil other than straight weight or API SA/SB shall be fine. Most of these latest type air cooled 4-cyl engines such as Robin-Subaru, Honda, Yahama and Mitsubishis call for multiviscosity motor oil just like ordinary automobile engine does).

You can feed it with fancy full syn if it makes you feel better. I, for one, use Tech2000 full syn HDEO 15W40 on all my lawn mower, tiller, pressure washers, etc. and been doing well so far...
 
That genset is air-cooled, right? My Generac recommends synthetic 5W30. The initial fill should be changed after 8 hours of run time. Once/year or 100 hours would be fine after that.
 
Check the "Lawn Mower and Small Engine" section. There are several threads on this topic. I plan to use a dino diesel rated 10w30 on my next OCI - trying to find Delo 10w30. I am currently using Citgo syn 10w30 since my last change 2 years ago - the generator is not used a lot.
 
In the air cooled Honda's we run (not as big as your Robin), we use your typical 10W-30, same stuff as we run in our service vehicles. Some of these tools, like the big trencher, will sit for months at a time. Never seem to have a problem firing them up when we needed.

I'd imagine that Amsoil product Pablo linked would be perfect.
 
I have posted many times on this subject. Having seen (and fixed) many portable generators fail on dino 5-30 I suggest a synthetic of slightly higher viscosity.

Florida heat is tough, as is running an entire house on a 11hp generator. Example: my 2 air cooled Honda water pumps failed early with dino oil. 15W-50 M1 resulted in much longer engine life.

My Robin 11HP gen set has only seen M1 15W-50 with 50 hour oil changes. It has serious hours on it with 3 hurricanes and home construction, without any problems. The oil is even clean when drained.

Contrast that with the many failures (including my co-workers) run on thin dino oil. The engines get ultra hot, the oil gets very thin and the connecting rod bearing (really just an aluminum con rod) fails. Every time. This situation was repeated thousands of times here in hurricane central.

Remember that 500 degree cylinder head temps are the norm in air cooled engines under full overload. I have seen 280 crankcase temps with my digital thermometer.

Chris
 
Justin,
I recently purchased a Subaru/Robin generator, so went though the same exersize. Subaru recommends a 10W-40 if the generator is going to be used above 90 degrees F. I chose Amsoil MCF, their 10W-40 Motorcycle oil. It had all the properties I was looking for including the enhanced corrosion protection. Pablo can set you up with this one too.

Robin recommends a 10W-30 for their engines at all temperatures except for their generators. It seems they prefer a heavier oil for the constant, high loads that a generator can put on the engine.

I would also suggest running it under varying loads up to 5K watts for another 45 minutes and changing the oil at 1.5 hours. The Robin engines won't have the silver soup that is often seen in B&S and Tecumseh engines. They do generate some brass colored particles during the first few hours, and a 1.5 hour change will get rid of ~90% of that. I used Delo 10W-30 for the break-in. Put 10-20 hours on it before swithching to synthetic (Robin's recommendation).

Ed
 
Just a note:

Mobil has reintroduced my very favorite oil, the original 15-50, not EP. It has the higher ZDDP levels that air cooled flat tappet engines require.

Chris
 
Well, I ran the generator for about 1.5 hours yesterday.
(Had to do my rear brakes and used it to power the air compressor) I figured i'd run it a little more before changing the oil. Then I changed the oil with Formula Shell 10w30 SM rated. The old oil had some brass colored particles in it.
I originally chose the 5w30 because we have seen temps in the
7-20F degree range, and I had some left over from my camry lof. The Generator has approx. 3 hours on it now. How long should I run it on this Dino, before changing over to syn.
I bought 1 more quart of Formula Shell 10w30, and a quart of Mobil 1 10w30. I wasn't sure if I should run it like another 2 hours on this, then another dino for 2? then Syn? or just go to syn after this run of dino? Should I run this dino for another 5 hours and change to syn? I dunno.

Thanks again for your help,
Justin
 
I think I'd run dino for a few hours (3-5?)repeat if necessary, and not switch to the synthetic until the amount of "flakes" is near zero.
 
I break in my small air cooled non-oil filtered engines by using the recomended Dino oil and change it at 1 hour, 2 hours and then at 6 hours and again at 12 hours. I flush the crankcase out with solvent on the first two changes and then at the 12 hour mark. After the 12 hour change and flush I fill with 10w-30 Mobil 1 that stays in till either 25 hours if the engine is under heavy/dusty/hot use or at 50 hours if the use is less harsh. I have had very good luck with my small engines using this process. It may seem like a lot of changes, but small engines use little oil and no filter so cost is minimal. You can't hurt your engine by over doing the oil changes, however you may shorten the life of the engine if you don't change it enough especially during the first few hours when it is wearing in.
 
I'm using GC in my Briggs powered gen set.
It doesn't run much. If we ever have a storm that kills the utility power I'll find out how good it is.
 
There's a lot of good advice in this thread, particularly from Cujet, Quest and EdHackett.

I'd use Mobil 1 15W-50 in an air-cooled small engine, because it is a bit thin for a 50 weight, but I wouldn't use a 20W-50 mineral or other brand 20W-50 synthetic as I'd be afraid it would cause too much drag and the dipper/splasher on the crank or rod may not splash the thicker oil as effective as a slightly thinner oil. Hard to see where the line should be drawn, but I've tried 20W-50 mineral oils in small engines (an old wood splitter comes to mind) and the engine seemed to be laboring, even when under no load.

My favorite oils for these applications are the 15W-40 mineral and 5W-40 synthetic HDEOs. Great additive package, good weight for sustained heavy use. Although, if the engine is still fairly new and you want to stick with a manufacturers recommendation of a XW-30, be sure to use a shear-stable synthetic or synthetic blend such as Schaeffer, Amsoil, GC, etc ...

I'm another fan of breaking in a new motor using mineral oil and draining every 2-3 hours to flush out the break-in debris. This stuff can get pretty nasty, pretty quick. After you see the dreaded "silver soup" once, you'll cringe thinking of all the people who don't do this. For this initial break-in period, I'll use any old 5W-30 or 10W-30 because it is drained so frequently.

Another thing people should do more often is change the oil in the middle of a prolonged event. Using a generator or water pump for a day or days at a time? Consider changing the oil when the machine runs out of fuel. What will it take ... 2 or 3 minutes? (Assuming you're prepared ahead of time.)
 
It seems like a lot of people are recomending 15w50. Please consider the fact that I live in nh. And the temp can get rather cold here. I am nervous that running a 15wX may be to thick for this application. The yearly temp range is usually
-20 F to 85 F. I currently have Formula Shell 10w30 in the engine now. I had just a couple of hours on the GTX 5w30 before I changed it. I plan to run M1 10w30 after break-in.
What about Rotella Synthetic 5w40 would this be ok? would it be too thick in winter, or too thin in summer?
I understand that a 15w50 is ideal in florida, as Cujet has suggested. But would it be ok here year round ? Who makes a better syn? Shell RTS, M1, or PP ?
Sorry I just got a bit confused.

Thanks,
Justin
 
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