Hacker News new | ask | show | jobs
by luma 1415 days ago
One of the major benefits of a two stroke engine is the simplicity of the design, which lowers cost, reduces size, and increases reliability. Your proposal is a net loss on all these factors.

A far better solution is to replace these sorts of things with battery powered electric solutions.
2 comments
bradfa 1415 days ago
2-strokes output more power. This isn't my proposal, this is a thing which exists in the world today, produced by various different engine manufacturers for sale to the public today in motorcycles.

Miniaturizing it to work on a hand-held lawn care device is just an engineering task.

link
snovv_crash 1415 days ago
It needs a high pressure rail with fuel pump, electronic injection and ignition control. This adds considerably to the cost, which when you take it into the engineering optimization problem, starts pointing to electric plus batteries for these small sizes. You need about 100cc before it makes sense to start looking for fuel engines, or some application that requires really high energy density for long endurance at light weight (eg. surveillance drones).
link
sojournerc 1415 days ago
Intuitively I think an injected engine would be more reliable. Gummed up carburator causes the pull-start blues for me frequently on my chainsaw when I haven't used it for a while. I do get a nice arm workout though.
link
tzs 1415 days ago
It was the same with my lawn mower. It only gets used maybe 6-8 times a year. For some recent years here were how many days it had been idle before each use: (245, 22, 14, 15, 14, 33), (258, 24, 12, 13, 17, 11, 38, 71), (167, 21, 21, 20, 15, 61).

Two simple things fixed that:

1. I switched to gasoline that does not have ethanol added.

2. Once every 2 to 4 weeks in the off season I start it and run the engine for a minute.

The container I use to store gas holds about two years worth and the mower runs fine on the the two year old gas. I do add fuel stabilizer. The bottle of that claims it is good for 2 years but my previous bottle was 6 years old when I replaced it and the mower was fine on 2 year old fuel with 6 year old stabilizer.

If you live near any body of water big enough to attract boats you might try at marinas. CENEX also often sells it. Here's a site that can help you find it locally if you are in the US or Canada [1].

I do not do any winterizing procedure for the off season. I asked the repair place I took it too one year when it would not start before I started doing #1 and #2 if winterizing was necessary if you were running it occasionally, and they verified that you only need winterizing if it is going to not be used.

[1] https://www.pure-gas.org/

link
mizzack 1414 days ago
100% agree on the ethanol-free gas to reduce carb gumming.

For overwintering, I just detach the hose after the fuel filter and drain the remaining mower fuel back into the can. Or, on small push mowers where this isn't possible, use the fuel shutoff and just leave the gas in the tank.

Then run the mower until it dies. Doesn't take more than a minute.

Finally, unscrew sparkplug(s), pour a teaspoon of motor oil into the cylinder (keeps rings from seizing/rusting).

Leftover gas in the can gets put into vehicles at the end of the season so I'm not storing stale gas.

link