My push lawn mower that I use for trimming where my Kubota won't go has an engine knock, would anyone know if I put in a heavy grade oil or an additive or both would help get me some running time on the this engine, it is a Powersmart 170cc any comments please .
My Kubota Helper
- Thread starter bluelight16
- Start date
Heavy weight oil will take up some of the clearance that is causing the knock, but you have to realize that it won't cure the cause. Do you by chance mow hilly terrain with this mower or the sides of hills?
NCL4701
Well-known member
Equipment
L4701, T2290, WC68, grapple, BB1572, Farmi W50R, Howes 500, 16kW IMD gen, WG24
If you’re not already running straight 30W (not multi-grade), I’d try that first. If it’s knocking with straight 30W, I’d switch to 30-50. Run it until it blows up and either bolt on another motor or get another mower.
Yes, I looked up a Powersmart 170cc. Unless my search failed me, it’s not worth trying to rebuild that motor. More of a run it until it locks up situation.
Yes, I looked up a Powersmart 170cc. Unless my search failed me, it’s not worth trying to rebuild that motor. More of a run it until it locks up situation.
Ok thanks I will try heavy oil, the mower was cheap from HD and as the old saying goes you get what you paid for.
The reason I asked about cutting on slopes is that my mother destroyed one push mower per year mowing our yard that had quite a large number of slopes. The oil ran away from the crankshaft and you'd get a rod knock. I bought her a 2 stroke Lawn Boy mower and never had a problem again.
thanks to everyone for there suggestions, I decided to mix some 85w/140 gear oil with 10/30 motor oil, I turned the crank over a few trimes then gave it start pull and it started first pull and there is no knock sounds like it did when it was new, I don't know how long this will last but if I can a season out of it that would be great, thanks again
Outnumbered
Well-known member
Equipment
Kubota L3901, FEL, BB1260, RCF2060, FDR2572, Titan Forks, Caryall, 5' Tiller
A lot of people miss this one. Most of the small engines use a mechanical "slinger" for oil and if there is enough slope away from the slinger it will effective starve for for oil and in my case a premature detonation ending in the rod exiting the engine block.
Only pressurized oils systems for me now on my mowers. No problems on my hilly mowing in 30 years since realizing this.
90 weight gear oil is about the same as 50 weight engine oil. Get the heaviest single weight oil you can buy and add some Motor Honey or STP to it. Gear oil is not meant for internal combustion engines and will not do the engine any good.
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I have a Kawasaki FH721V that runs an oil pump. You can use it on slopes, but the manufacturer states nothing over 30 degrees if cutting along the slope or the engine will starve.A lot of people miss this one. Most of the small engines use a mechanical "slinger" for oil and if there is enough slope away from the slinger it will effective starve for for oil and in my case a premature detonation ending in the rod exiting the engine block.
I contacted Kawasaki directly and asked them the maximum angle that the engine can safely operate. I assumed since they manufactured the engine they would know. Sure beats laying out $1K for a new engine.