Briggs 22HP els motor backfiring loosing power I am stumped.

[ultrarunner]

Why would a multi-grade be detrimental?

Only asking because so often the recommendation is to use synthetic and I only see multi-grade synthetics.

 

[spokane 1]

Multi grade is designed for tight tolerances with water cooled engines. The engine warms and via coolant thermostat never varys in temp.

this is not true in small engines. air cooled 30 weight sae is the ONLY oil to use PERIOD......take my word for it.
small engines have sloppy tolerances with aluminum interior parts. the engines goes from regular temps to extremely hot under load..it requires a thicker oil that does not thin to water viscosity under extreme heat.

the owner manuals on all these engines request sae 30 for 60 degree temps.....Your playing with fire to grab anything off the shelf.
Im a old certified mechanic with UAW experience.

 

[IslandTractor]

Multi grade is designed for tight tolerances with water cooled engines. The engine warms and via coolant thermostat never varys in temp.

this is not true in small engines. air cooled 30 weight sae is the ONLY oil to use PERIOD......take my word for it.
small engines have sloppy tolerances with aluminum interior parts. the engines goes from regular temps to extremely hot under load..it requires a thicker oil that does not thin to water viscosity under extreme heat.

the owner manuals on all these engines request sae 30 for 60 degree temps.....Your playing with fire to grab anything off the shelf.
Im a old certified mechanic with UAW experience.

Thanks for the advice and explanation. Learn something new every day here.

 

[Sawyer Rob]

Multi grade is designed for tight tolerances with water cooled engines. The engine warms and via coolant thermostat never varys in temp.

this is not true in small engines. air cooled 30 weight sae is the ONLY oil to use PERIOD......take my word for it.
small engines have sloppy tolerances with aluminum interior parts. the engines goes from regular temps to extremely hot under load..it requires a thicker oil that does not thin to water viscosity under extreme heat.

the owner manuals on all these engines request sae 30 for 60 degree temps.....Your playing with fire to grab anything off the shelf.
Im a old certified mechanic with UAW experience.

That's NOT what the manual for MY Vanguard says...

It says, use 30W above 40F OR synthetic 5w 30 OR synthetic 10w 30 for ALL temps...

I've been using 10w 30 synthetic in my Vanguard 23 since I bought it in 2003 and it still starts/runs perfect! I can't detect any power loss at all, and it does not use any oil.

I would not use a 10w 30 that wasn't synthetic though...

SR

 

[rustydollar]

Yea we've been using a multi-grade 5/30 in our GM truck, anyhow the thermostat was stuck open the oil never coming up to temperature. Prematurely wore out the distributor gear triggering the engine light to light up.

With the worn gear engine timing was retarded after installing a new distributor and and new thermostat we had the engine re timed.

I still think it's a band aid repair as the gear on the camshaft will have been equally worn.

Something to be said about multi grade oils for sure and its not all good news.