Seafoams gets a +1, but i need 2cycle help

thatguy · May 1, 2011

Not sure where the best place for this was..

I have an old (+10 yrs) string trimmer (Echo) that my dad gave me.. I havent used it much in the past because it would take 45min to get it running and then it would be hard to keep running..

Testimonial -

I had heard about SeaFoam and decided to try it.. Removed the spark plug poured the seafoam in, pulled the starter to rotate the piston and poured more in.. Let set overnight.. reinstalled the spark plug.. choked it, first pull it fires right up... Smokes like a house fire, but that settled down after a few minutes... I was impressed...

Help me with a problem -
NOW - the problem is that it will run great for about 10 min and then starts to sputter/sput and then quits.. Give it a few minutes and it will then restart and run great for another 10 minutes.. I thought that the gas cap was building up pressure (could hear it release pressure when you took the cap off) and it was getting air locked, so I made the vent in the cap bigger which seemed to help BUT it now allows the gas to pour out of the cap if you turn it the wrong way (OOPS)... BUT it did run better, 20 min or so before it started slowly trying to quit. Its like it is starved for gas or air - sputtering, sputting.. you can feather the trigger to keep it going a little bit longer but untimately it quits....

air filter is clean

thoughts.. Ideas.. Suggestions

And NO using only 10 min at a time is not a viable answer.. sorry

Brian

fishman · May 1, 2011

This is probably a silly question so forgive me in advance. Are you sure you have the correct gas/oil mix? Too little oil can cause the engine to seize when it overheats and then it can eventually be restarted when it cools a little.

I would examine the old cap to see if it has deteriorated. Perhaps a new cap is in order?

groundcover · May 1, 2011

First see if it is a fuel or spark issue. Pull the plug wire when she shuts down and pull the spark plug, ground it to the motor and give it a pull. No spark , bad ignition issue, I had the solid state ignition go on my Echo Blower, lifetime warranty, replaced free. If you have good spark check for the fuel problem ! Good luck.

thatguy · May 1, 2011

"First see if it is a fuel or spark issue. "

The spark plug was brand new last year (one of those high dollar 'no foul' plugs) Also it runs great for a while, so I think a plug issue can be ruled out..

Someone commented on another forum to check for detoriated fuel line and replace the fuel filter - I am thinking those two will be my next step to rule out..

"Are you sure you have the correct gas/oil mix?"

I dont remember the ratio right of but it was mixed either 40:1 or 50:1, I looked it up online based on the model when I mixed it..

thanks

brian

JimRB · May 1, 2011

New spark plug does not tell you if you have an ignition/spark issue. Coil packs have been known to fail with heat but start to work again when they cool down. I vote for fuel issues but you need to be comfortable taking a carb apart to inspect and clean.

fishman · May 2, 2011

JimRB said:
New spark plug does not tell you if you have an ignition/spark issue. Coil packs have been known to fail with heat but start to work again when they cool down. I vote for fuel issues but you need to be comfortable taking a carb apart to inspect and clean.

I agree with this. You can also run a small bit of seafoam in the gas to see if that cleans up your carb. I have successfully done this with small engines with carb issues.

mostly_gas · May 6, 2011

Pull the plug after running it till it quits. It will likely be wet if no spark is stopping the engine. If changing the vent in the gas tank helped, I think you have a fuel delivery problem. At ten years old the fuel lines may be shot, fuel filter may be plugged or the fuel pump ( probably part of the carb) needs a new diaphragm. Replace your gas cap while you are working on the weed eater.

mostly_gas · May 6, 2011

BTW have yet to see a plug that won't foul in a two stroke. Modern ignition systems help but you just don't get near the plug life in a two stroke. It is easier to change a plug than almost anything else you can do, and works surprisingly often.

2manyrocks · May 6, 2011

First impression is that you need to rebuild the carb.

I have an older Echo that runs like a top after I rebuilt the carb. These older machines are quality built if they aren't worn out.

They were built for nonethanol gas, however. You will have less problems if you use 100% gas.

thatguy · May 7, 2011

Just a few more thoughts.. it has been mentioned that the ignition may be breaking down when it gets hot - I found a few CDI modules online but they sell for close to $80.. Im not going to drop that much on something this old..

I pulled the fuel tank last night and the fuel like appears to be in good condition and i recently replace the fuel filter.. still need to find a new fuel cap OR rebuild the cap i have since I 'modified' it a tad too much LOL

I also found a few posts online saying those symptons are a sign its on its last legs.. Not sure if i believe it or not since it does wrong so strong when it does run

Thirdly.. - downloaded the owners manual last night (after I figured out what model it was)... it is suppose to run on 25:1 or 32:1 gas mix... OOPS.. Looks like that could be the issue - Since 40:1 is about all you can buy in the small containers Im sure that is what I have been using.. the manual does say it can run on 40:1 'special fuel approved by echo'

brian