Advice on Oil for older Honda motors ?

It is Queens Birthday weekend here and the likes of Repco and Supercheap have good prices on motor oil.
Both my Hondas are powered with older GXV120 as are my project motors waiting in the wings.
I have always had older motor vehicles too and when they had a few miles on the clock, ring and bearing wear etc, I would use a heavier oil.
My question is this; what weight oils do you use in your older mowers, especially Honda?
I have a preference for Penrite and this is due to my experience when I owned a Evo 1340. Where other oils showed a lack of viscosity at temperature after a long run, say Auckland to Kaitaia when the oil light would flicker at idle, when I changed to Penrite this no lomger happened and the oil still had viscosity (using the slip test with fingers).
Honda advise 10/30 weight. Penrite has a 10/30 small engine oil but would it be sensible to use their 30 weight or their 15/40 Vantage?
https://www.repco.co.nz/en/brands/penrite/penrite-vantage-15w-40-6l/p/A1262663

Penrite oils
http://www.penriteoil.co.nz/tech_pdfs_new/April2013/Small Engine_April2013.pdf

You should always run mower oil in mowers.

Heavy oil is no substitute for new rings and rings are cheap.

Honda use 10 w oil to make them easier to start, particularly when cold
I put strait 30 in Honda mowers down here, 10w30 in pumps & generators and 10w40 in hand helds.

The heat characterics of a governed engine are a lot different to a motorcycle.
You cant run one way faster than it can cool as you can on a bike

Thanks Bert. The 4 running Hondas all blow white smoke for a very short moment on start-up only. Otherwise they a clean runners.
Temperatures down here dont reach much above 28-30C on average, with lows of Winter in 10-20C.
Is 30W suitable at those temperatures?
Penrite have a range from 10/30, 20/50, 30. The 30 and 20/50 are both full zinc.
Zinc is a good thing, right?

I'd stick with 10W30 or switch to 10 weight as bertsmobile1 states if you're willing to give up something at start-up. Beyond that, I wouldn't change viscosity unless the situation warranted it.

slow_runner said:

Thanks Bert. The 4 running Hondas all blow white smoke for a very short moment on start-up only. Otherwise they a clean runners.
Temperatures down here dont reach much above 28-30C on average, with lows of Winter in 10-20C.
Is 30W suitable at those temperatures?
Penrite have a range from 10/30, 20/50, 30. The 30 and 20/50 are both full zinc.
Zinc is a good thing, right?

Click to expand...

SAE 10 weight oil is fine at temperatures from 10-30C and even a little beyond. I'm not certain what you mean by "full zinc". Zinc has been a common additive in motor oil for 50 years primarily because of its anti-wear ability by enhancing lubrication and because it's a cost effective way of doing so. In addition, zinc reduces oxidation. However, "zinc" in this regard really refers to compounds created with zinc, primarily ZDDP or ZDTP.

" full zinc" is highlighted in the Penrite bulletin Tony - page 7 http://www.penriteoil.co.nz/tech_pdf..._April2013.pdf

I have read where it has been said that the zinc component is reduced/replaced in a number of modern oils, so I guess that Penrite are maybe marketing the difference?

slow_runner said:

Thanks Bert. The 4 running Hondas all blow white smoke for a very short moment on start-up only. Otherwise they a clean runners.
Temperatures down here dont reach much above 28-30C on average, with lows of Winter in 10-20C.
Is 30W suitable at those temperatures?
Penrite have a range from 10/30, 20/50, 30. The 30 and 20/50 are both full zinc.
Zinc is a good thing, right?

Click to expand...

Yes it tends to be a little cooler is the Shakey Isles than it does here in Sinny on the Mainland.
And yes I do run Penrite in my old motorcycle but not in lawnmowers unless it is a lawnmower oil.
lawnmowers get used very infrequently and then usually for short periods so the entire package used in mower oils is substantially different in mower oils than it is in motorcycle oils which are again different to car oils.
Zinc is mainly there for anti scuffing on cams and to protect bronze bushes.
It is an extreme load lubricant and not really needed in a mower oil but a good idea in your bike.
Mower oils contain a lot more corrosion inhibitors and stabilizers than any other oil apart from fork & hydraulic oils.

If the mower blows a little white smoke at start up then either it is getting too hot or the valve stem oil seal on the inlet valve is on the way out or the valve itself has a bit of stem wear.
10W30 will suit you quite fine in mowers & snow ploughs.
Or plain 30 in the mower , which will make it a little harder to pull start when cold .

Well said Bert.
Penrite 10/30 looks to fit the bill and the local outlet stocks it.
I will be getting some tomorrow as it is pi**ing down here at the moment and has been doing so all day:frown:

Wanna send some of it over here ?

My vintage & worked hard Honda FG 100 Mini-tiller I use 30w, no problems.

1/2 pull on the rope & it's idling away. I didn't get an online repair manual till after I had done a lot of work on it including a engine flush & some fresh 30w oil.
Book says 10w-30 but I'm not gonna do that. It's very happy on the 30w imo.