bill67 wrote on 04/05/13 at 15:38:32:

Motorcycles over the years probably 20, snowmobiles 0 I live in TX
things that use 2 stroke engines I couldn't even begin to estimate how many I've owned.

R.F.

I have been waiting for years for someone to devise a repeatable test for SeaFoam and other comparable additives. Personally, I think they are useless despite the apocryphal stories of the magical cures wrought by them. I suggest you type into your favorite search engine the term "MSDS" and your favorite product. In the case of SeaFoam you will find it contains naptha (lighter fluid); Pale Oil (SAE 20 oil); and isopropyl (rubbing) alcohol. Which of those three do you think is a better solvent than plain old gasoline?

OK......I was going to avoid posting on this again....as I believe that trying to run this engine without cleaning the carb is a huge mistake....however I will tell you how to adjust the carb on a 2 cycle engine.  (And so that Bill believe my credentials I have worked on chainsaws since 1973,  and I currently own 3.  I have probably repaired a couple of hundred chainsaws, along with 2 cycle tillers. hedge clippers and weed wackers.  Most of the problems have been from sitting with old fuel in them, as these are seasonal use items and sit more then they are ever used).  

A 2 cycle engine needs to run rich when no load is on the engine, and it will run cleanly when a load is applied.  The sound you are looking for is called a "burble" or "4 stroking" in the trade.  If the engine currently is running - just start with the current settings on the carb.  There will be 3 screws and one should be marked (L) which is the low speed mix, one should be marked (H) which is the high speed mix, and the idle speed may not be marked or might be marked (A).  You should adjust the idle mix just like you do for a 4 stroke engine....you turn the screw in until the engine speed drops, then back it out until the speed increases and then just a bit more until you hear the engine tone change to rich.....then turn the screw back in until the engine runs smoothly again.  Then adjusting the high speed screw is painful, as it requires that you run the engine with the throttle wide open.....although it doesn't have to be very long.  The engine should not run smooth at full throttle with no load.....it should run rich and hav a "burble" sound.  You can pull full throttle and adjust the (H) screw in until the engine speeds up - then adjust the screw out until the engine just starts to burble and run rich.  The engine should have this sound until you put the saw into some wood and start cutting under a load.  Small branches and light loads should still have a bit of a burbling sound -but when you start cutting with a good load the engine should run clean and strong.

Here is a link to a the adjustment from Madsen's, which is a very reputable shop.  The page includes sound clips for the idle adjustment and for the high speed adjustment.  You can hear what the sound should be when adjusted correctly.
http://www.madsens1.com/saw_carb_tune.htm

I, Too, thot "All fuel additives are created equal. None do a thing."
Then, I poured Sea Foam into my back hoe. It was making a hard clacking sound that made me think something was gonna come thru the block, but, I knew it was an injector. In about 5 minutes, the sound was much diminished. After that, when I fueled up, if I forgot to add it, it would clack. I recently had the injectors re-worked & no longer need the Sea Foam, but I have some around, because it works.

Dave wrote on 04/07/13 at 13:53:53:


That's what I've been trying to relay as well,  fuel additives/Oil additives are maintenance items to be used on something that is still running, They are not a magical liquid that will make a non-running engine run properly or fix a mechanical issue that requires you to replace parts.

I myself in my cages use a fuel cleaner additive once a month to keep the injectors clean.  I will not go into brands here but it's not SeaFoam as I refuse to pay that kind of price for something that will do the same job and is made of the same exact stuff for a much lesser cost.

R.F.