Uh oh. Ran the wrong gas in my trimmer; now it's seized up.

I goofed up! I accidentally put straight gas in my Shindaiwa trimmer. It ran a few minutes then stopped and wouldn't start. That's when I realized what I had done. I think the engine seized up (it wouldn't pull to start).
Is there anything I can do?

 

What model do you have and how old is it? I'm wondering if it's worth putting much into it for a repair versus shopping for a 4 stroke trimmer.

 

The only way to know how bad it is is to take it apart and see what got ruined.

 

Do they even make 4 stroke trimmers?
I've only ever seen 2-stroke units here. Would imaging a 4-stroke would be pretty heavy.

I'm pretty sure you'll be looking for a replacement unit or at least a motor (if you can find one cheap). These trimmers sell so cheap now, just the labor to repair would probably cost more then a new unit.

 

Shindaiwas don't go cheap... you're looking at $300 plus. They do have 4 stroke trimmers but they are not preferred in my opinion.

 

I have a 4-stroke Honda and a 2-stroke Stihl. I like them both but for different reasons and they cost about the same.

For residential use cutting "normal" grass the 35cc 4 stroke Honda has more than enough power and it is boringly easy to start and it just sits there making a cute little put, put, put sound as it idles. It throttles down well so you can easily trim delicate areas. It's great on fuel. There is no worry about mixing gas and it's quite smooth so your hands don't go numb if using it for long periods. Where it falls short is in brute force for turning a saw blade or trimming through heavy overgrown weeds & briars.

The 36cc 2-stroke Stihl has much more power and shines on heavy cutting tasks. It runs best with full length of lines out and with a load of at least light grass on it. Without a load it misses as if saying "come on give me something to chew". It is difficult to hold it at less than full throttle so it can be a bit much when detail trimming. It vibrates noticeably more so if I go through a tank of fuel in one stretch my hands are shot for a couple hours. The fuel consumption is somewhat higher than the Honda but with such a small engine it's not a big deal. And, it's about 2 pounds lighter than the Honda.

 

I won't get into the debate of 2 vs. 4 stroke as they each have their place. I just never had seen a 4 stroke trimmer.

Also love the smell of 2-stroke exhaust (snow mobiles especially).

 

Remove the spark plug and dump some penetrating oil, PB-Blaster, Liquid wrench, acetone&ATF, in the cylinder and let it set overnight, now you need to get to bolt under the starter, remove whatever it takes to remove the starter rope housing, after the trimmer has sat overnight put a wrench on the crankshaft nut and rock it back and forth it should break the rings and bearings loose, if not add more penetrating oil and wait another day, when it comes loose turn the engine clockwise for several turns, put it back together. Check the compression to see if anything(rings) got broken. Have a good one. Geo

 

I assume you mean one of that list, not all? I have liquid wrench penetrating oil (and another brand). Others have mentioned soaking it in 2-cycle oil overnight; would that be better/worse?

Thanks.

 

Any one of them will work, use the penetrating oil, 2-cycle oil is not meant for this purpose. If you can't get to the nut on the crankshaft you can use a 1/4-3/8 in dowel through the spark plug hole and smack it with a hammer, your trimmer is a quality product so don't give up on it. Have a good one. Geo

 

I've been soakin' and smackin' (using penetrating oil and a dowel). Should the cylinder physically move down when I smack it? (It ain't yet).

 

Yes and/or no.
If the piston is at the bottom of the stroke, it's not going to go any further, despite how much hitting.
Personally, I don't like sticking foreign objects into the cylender head.

Try removing the recoil and turning it with a wrench (with the sparkplug removed). If/when you get it moving freely, re-assemble the coil and pull it over a number of times with the sparkplug hole facing the ground to blow out any left over oil (saves your plug).
If all is good and lucky, mix the first tank of fuel a bit richer then normal.

 

Sorry I didn't get back earlier on this. Much appreciation to everyone. I was able to free it up and it seems to be working the same as always. I just used a penetrating oil as suggested, tapping the cylinder lightly with a wooden dowel every day. It freed up in about a week.

 

Success is a wonderful sound. Have a good one. Geo