Do it Yourself: Re: [DIY] Trimmer Hi/Lo tuning

13 April 2016

Re: [DIY] Trimmer Hi/Lo tuning

2 cycle engines do not pass the fuel directly into the cylinder because they do not have intake and exhaust valves like 4 cycle engines . It passes first through the crank case and is metered via the flutter or reed valve. If the reed valve is cracked or if there is an air leak where the two halves of the crankcase are joined they will not run right. This link may help you see what I am talking about. It also has an animated diagram

https://en.wikipedia.org/wiki/Two-stroke_engine

Flat_Land Dale

subprong subprong@gmail.com [DoIt_Yourself] wrote:

Well, speaking of leaks.

I had replaced all of the hoses, fuel filter and spark plug. Also washed the air filter and wiped/sprayed out the exhaust port as best as I could. At some point, I took apart the carb just to make sure the diagrams/gaskets weren't ripped or cracked. After several cranks and switching between chokes several times, it finally started. It was used and worked fine so long as there was only a hair on the trigger.

I let it set for a week. The true test being whether it would fire up again. Of course, it did not. At this point, I decided to spray in some sea foam into the spark plug hole. It didn't start up so I simply let it sit for a few days and let the foam do its duty. A few days later, I noticed that all of the fuel had leaked out of the gas tank somehow. I'm not even sure how this is a possibility but gas was in the air exhaust port area.

After inspection, I really couldn't tell exactly where it was coming from....only that I saw it collected at the bottom of the port. I took apart the carb again, dried everything up and even removed and re-installed the.... well, I've forgotten the name. A very small lever in the carb with a very small spring underneath it. Made sure there was no blockage in there. I put the carb back together and reattached to the trimmer. I made sure that the carb was seated very securely just in case it was leaking out of that area and perhaps dripped back into the air port.

Later, the trimmer worked as it did before. Usable and working but only with a hair trigger.

On Tue, Apr 12, 2016 at 2:05 PM, Dale Schoepflin dalu@hbcomm.net [DoIt_Yourself] <DoIt_Yourself@yahoogroups.com> wrote:

You may have an air leak at the crank case and be losing vacuum.

Flat_Land Dale

subprong subprong@gmail.com [DoIt_Yourself] wrote:

Tried to fix up a trimmer for a friend. After much replacing of items, it finally started up. However, it only runs when the throttle is only very, very slightly pulled. Any more throttle and it dies.

Is this a Hi/Lo tuning issue? I cannot find anything in the manual or online that shows how to factory reset the dials (Hi/Lo/Idle) to neutral in order to work off of that point.

Virus-free. www.avast.com