4-cycle trimmers -- is it safe to run upside down

[jas67]

I just purchased a LEHR ST025DS 25cc Propane Powered 4-Stroke Detachable Straight-Shaft Trimmer. This model can take various attachments, including a pole-trimmer saw.

Now, I know that aside from lighter weight, one of the reasons that chainsaws use two stroke engines, is because they can be run at all angles w/o worries of starving the engine for lubrication. What about 4 cycle engines in hand-held equipment such as this? I'm I going to ruin the engine in this trimmer if I put a pole-saw on it (which requires it to run upside down)?

Thanks,
Jay

 

[jwstewar]

I'm not saying it is right or wrong, but I've got an old 4-cycle Ryobi that I purchased in 96. I've used it at every angle imaginable. I have no idea how many hours on this thing, but it is bunches. I've never experienced any ill effects. These things don't run an oil pump, they are like the lower end B&S engine that count on slinging the oil up into the engine. If it is upside down, it isn't having to sling the oil up, it is already running there via gravity. That is my opinion at least.

 

[jas67]

The answer I got back from Lehr was:

Hi Jay,

Thank you for contacting LEHR Incorporated and for your interest in our
Eco Products.

When using our Eco Trimmers you can turn them sideways or even upside
down for a while without hurting the engine. Just make sure that the oil
level is not too high.

Also on the Eco Trimmers there are two positions that you can attach an
attachment, so you can have the engine straight while the attachment is
sideways.

I hope this helps. Please let me know if you have any further questions.

Thank you,

David Kurens
Customer Support
8922 Ellis Ave.
Los Angeles, CA 90034
Ph: 310.839.9009
Fax: 323.370.6811
dkurens@golehr.com
LEHR - Environmentally Friendly Technology​

 

[arrabil]

My Ryobi 4-cycle went poof after three or four minutes of straight up/down usage. I was pruning trees with it. When I took it apart, the piston had seized from lack of lubrication. That was in hour six or so from new.