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.

I just bought the Honda HHT25SLTC Trimmer Bush Cutter.Four CYCLE engine. It is a bit heavy, but the shoulder strap makes this bearable with no real effort. Last year I bought an Echo two cycle with the head that uses replaceable strings. The string is easy to replace, but one must start the engine each time. This can be very tricky with a two stroke engine. It worked fine last year, but his year it wouldn't start reliably. I called the service depots and couldn't get it looked at for about six weeks, because the yard was full of two strokes requiring repair.This was a message to me. NO MORE TWO STROKES. I might add the Echo gas tank leaks through the gasoline gasket, and they use a gas line that deteriotes in gasoline, believe it or not. Anyway I bit the bullet and purchased the Honda. What a marvellous machine. I even learned how to wind the string on the bump real, which is easy after one knows the method.The instruction manual is well written. Apparently all those English Teachers in Japan are having an effect. My yard is large and I needed a reliable product, and this Honda meets the requirement. Expensive yes, but it is well made. I gave the useless Echo away, since there is no second hand market for two strokes that usually don't start reliably. Such is life. Durgan.

The trimmer you write about is most likely a Homelite trimmer manufactured for John Deere and sold at the Home Depot (I have one too - and love it). Regarding the bulb - instead of looking for a Homelite or JD Primer bulb, do a generic search for "primer bulb". I don't think they are mfged for a specific model/engine type.

Please give me some feed back on my related post on page #1, "Will all trimmer's primer bulbs work the same?" A reply to rcrown@charter.net: Fuel line diagram link below: The fuel line on the Craftsman Weed Whacker probably could have been replaced w/m removing the carb. It was straight forward 2 ports (carb and primer bulb, 2 holes in tank that could serve either port. The challenge is getting the line into the tank. Simple! Cut the line at a thin angle 1" or less that will slide into the tank and push with needle nose pliers or tweezers in needed. You should see enough line in the tank to pull the full dia the length you need (with needle nose pliers or tweezers)into the tank which seal to the tank from being tight. http://media.fotki.com/1_p,srggdwfqbktrkttxgtqsskgwtqkq,vi/ttfrfwdtqxrkddbgrwkxrqkbrswfb/1/1303472/5961857/image5991553081932560263img-or.jpg