Honda EG650 Gen. Best Oil ? Spec is 10-40

Joined
Jun 22, 2004
Messages
259
Location
upstate NY
I know.....I'm still not sure when I can safely change the spec to a different weight. I have plenty of 0W, 5W-30's even GC from a sale a while back but I don't want to ruin this old beauty. Does it really need the 10 in hot weather?
 
Upstate NY, if really upstate you will never pull start it at 0 with a 15w in it. I had to go to synth. 0w-40 to winter start my 10hp briggs 6k unit in sub zero temps. in the ADK . Even with synth. 5w-30 in it the recoil pull would lift the gen. set off the ground without enough spin over to start.
Plenty of 0w-40 on hand as that's what's in the SkiDoo's .
 
As a very general rule, 0w oils tend to shear more rapidly. A 0w-40 would at first seem like a great choice. However, in air cooled engines any of the 5W or 0W oils tend not to hold up all that well. They achieve the higher viscosity rating through the use of viscosity index improvers and the use of high quality base stocks.

An example: 5W-30 mobil 1 has an HTHS (high temperature viscosity 150 Deg C), of 3.1, where as straight dino 30 oil has an HTHS of 3.8. The 100C rating for both is 30 (5W-30 vs 30) , but clearly the straight viscosity oil is more suited for the high temps of air cooled engines.
 
Upstate NY, if really upstate you will never pull start it at 0 with a 15w in it.

That might be true with a larger generator. But the unit in question is a 650 watt hand carry unit. It's a flat head 97cc engine with a 5.6 to 1 compression ratio, and it's easy to pull over, regardless of oil choice.

I have the 500W version and I use Mobil 1, 15W-50. No problems what so ever.
 
Since the EG650 was originally sold 30ish years ago, ANY modern oil is going to far and away exceed the oil that was originally specified (SF).

I have an early 90's EG1000 and the owners manual for that calls for 10w30 which would be fine in the EG650, too, I would expect. The main thing is to keep it full and clean. I'm running 5w30 Rotella Gas Truck in mine at the moment and it sounds great and hasn't consumed any oil, though we've only used it on a couple of camping trips this year.
 
Here's a link for the 1995 version of the EG650 owners manual. The specified oil is not 10w40 in this publication, but 10w30 is preferred for temps up to 85f or straight 30w for 50f and above.


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If you're upstate ny you can safely stick with a 10w30 for all year use.. If you really want you can run a hd sae30 summer months. I don't see a need to change to a 40
 
I know.....I'm still not sure when I can safely change the spec to a different weight. I have plenty of 0W, 5W-30's even GC from a sale a while back but I don't want to ruin this old beauty. Does it really need the 10 in hot weather?
Just noticed your previous entry. Sorry to hear.
 
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