SuperTech 5w-20 in a B&S Lawnmower engine

[84zmyfavorite]

I recently got a Craftsman pressure washer with a seized B&S 6.75ftlb engine for free. After using WD-40 to Un-Seize the motor, it has been running like a champ. I put the engine on my Craftsman walk behind mower as its 5Hp B&S is worn out. Has been running like a champ for a month and a half now, so decided to change most likely factory oil out for fresh. I am using SuperTech 5w-20 for this Oil Change. I have a reason that I am using such a low weight oil, but I wont reveal it today. What do you all think?

 

[jeepman3071]

Originally Posted By: 84zmyfavorite
I recently got a Craftsman pressure washer with a seized B&S 6.75ftlb engine for free. After using WD-40 to Un-Seize the motor, it has been running like a champ. I put the engine on my Craftsman walk behind mower as its 5Hp B&S is worn out. Has been running like a champ for a month and a half now, so decided to change most likely factory oil out for fresh. I am using SuperTech 5w-20 for this Oil Change. I have a reason that I am using such a low weight oil, but I wont reveal it today. What do you all think?


I doubt it will harm the engine, but I wouldn't be surprised if it burned quite a bit of it.

 

[tommygunn]

As its in a pressure washer I dunno. Its probably fine but its pretty thin. I'd expect operating temperatures to still be pretty intense and oil shear, fuel dilution and high temperature oil breakdown to be contributing to a lot of oil thinning.

I certainly wouldn't run it. I've had 5w30 shear down and burn off even. Assuming the oil doesn't burn off on you I bet it'll keep running fine though, check it regularly.

 

[Trav]

Splash lubed ball bearings, the thing could probably run on 3in1 (not really). It might use some though as the other poster noted.

 

[Hootbro]

Originally Posted By: 84zmyfavorite
............. What do you all think?


I think it is stupid to run such a low weight oil. Lowest B&S has ever recommend was a 5w30 and only if it was a synthetic.

Your going to have consumption with that 5W-20.

 

[bepperb]

" Lowest B&S has ever recommend "


Nooooo...... they recommended 20 weight oils for cold temps into the 70's. My manual actually states to dillute the 20 weight oil with kerosene if starting is still difficult.

I doubt you'll have a problem with the 20 weight, but I'd keep an eye on the oil level. Funny that it seized on factory sae 30, any idea on why?

 

[TFB1]

I took temperature readings on two '80s B&S 3.5Hp engines I have and both read around 275* on the block at the little side valve cover... Oil does flow through this area... The one that has had a thorough cleaning of the cylinder cooling fins runs around 220* at the bulge on the block that's over the cam gear(lots of internal oil splash in this area), while the other with minimal cleaning measured 236*... It was approx 15* hotter the day I took readings on this one...

5W-20? I'd oil the wheels with it...

 

[ARCOgraphite]

Originally Posted By: Trav
Splash lubed ball bearings, the thing could probably run on 3in1 (not really). It might use some though as the other poster noted.
I though the rod big end was plain bearing with a dipper? (At least on the 3.5hp)

 

[TFB1]

Originally Posted By: ARCOgraphite
Originally Posted By: Trav
Splash lubed ball bearings, the thing could probably run on 3in1 (not really). It might use some though as the other poster noted.
I though the rod big end was plain bearing with a dipper? (At least on the 3.5hp)


I'm yet to see a B&S with any ball bearings...

Originally Posted By: bepperb
Funny that it seized on factory sae 30, any idea on why?


Probably lack of....

 

[JR]

b&s suggest 5w-20 up to 1991. my vanguard calls for 5w20/30 syn only below 0degrees.

kc

 

[wag123]

Originally Posted By: TFB1

I'm yet to see a B&S with any ball bearings...

You haven't had any horizontal shaft engines apart, have you?

 

[Trav]

Yes it is. The last one i did had a coating similar to those found in some oil less small compressors.

 

[stxonall8]

Well this isnt fair lol, I was hoping to see the reason for this.