Does anybody have a Homelite St-275 trimmer? I need the oil-gas ratio!

S

Squashfan

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Jun 6, 2012
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A very generous person gave a free running Homelite St-275. I have looked and looked for the oil-gas ratio. My Google-Fu is weak and I cannot find it. Can anybody help me?

EDIT: Actually, this was 3+ years ago I got this tool and the person who gave it to me didn't know the ratio either. I got the weedeater running on a 40-1 gas oil this morning. But I didn't see any smoke which worries me that I have the ratio to lean.
 
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I run 50:1 in all my handheld 2-strokes, regardless of the recommendations. Modern oil is so good that it does not require a richer mixture.
 
I've had many homelite string trimmers over the last few years. They have all been 50:1. Even after they switched rotation direction which I assume was due to a different motor, it stayed 50:1. Also, every single one I have owned has broken the muffler. It doesn't affect it running, but it sure does scream pretty loud! I just put ear buds in and crank the music up :D


-X
 
40:1 and 50:1 are very common proportions these days. A richer mixture will only provide more lubrication, and more smoke, and foul up the plug a bit faster. So if in doubt add a bit too much of oil rather than not enough.
 
Old Homelites were 32:1.

"I have a Homelite ST-275 (25cc powerhead) from the same vintage as your HLT-16. I believe that the manual recommends 32:1 oil/gas ratio.
I have used multiple different oils in mine over the years. The majority of the time I have run at a 50:1 ratio. Mine is about 14 years old, and I would estimate has between 100-150 hours usage. I am currently using Mobil 1 Racing 2T at 50:1 in mine."

"It is listed as 32 to 1, but you could run Echo Pro-mix at 50 to 1 with no problems. Opti-1 is good also, as rredogg stated. I'm just a little nervous about some of the ratios they suggest, like 100 to 1."
quote from here
http://forums2.gardenweb.com/forums/load/tools/msg0410182422262.html

You can find gas/oil ratio discussions/fights:D all over the web.
What ever you do, Remember to tune the carb for the ratio, so not to run lean.

I know this isn't a saw, but you can find where pro saw guys are shying away from 50:1 or less oil to favoring 40:1 and going back to 32:1 for more oil to protect the bottom end.
Take a look at some engine tear downs, they tell the story.
 
I called my dad and he had it written on an old gas can. It is 32:1. And I found out that I mixed the gas wrong. I put 4oz of gas in (a little less than) one gallon which works out to be... 32:1. So I already had the right mix and I didn't even know it. But I think it is running lean because of the lack of smoke and there was a strange burning smell after I shut the motor off. It did not smell right to me but it may be because of my inexperience.

Do you happen to have a guide to tuning carb for a newb? I saw a guy do it in a video but how do I know when I have the carb tuned right?
 
Thanks for all the help folks. I was pushed for time in my last reply and I didn't get to properly thank you all.

Well, I looked up some how tos for tuning a carb and it seems fairly straight forward. Not necessarily simple though. Just follow instructions like these: http://www.instructables.com/id/Tuning-Two-Stroke-Engines/step3/The-Nitty-Gritty/

And then through more research, I also found out this is illegal. Yay!

EDTI: I need to replace the fuel line too. They are leaking on the top of the tank. I wonder how I would find out what kind of line I would need?
 
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Go to a mower and saw repair shop, or a hobby shop. They will sell fuel line by the foot and it might also be a good idea to replace the primer bulb at the same time. If the fuel lines are cracked, the bulb is the same material as the line and might be ready to go as well.


-X
 
I think I may replace the fuel filter with the fuel lines. And maybe the gas cap too since I am pretty sure it is leaking. Or to be more accurate, that the gas cap lacks a seal.
 
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