# 2 cycle engine problems



## noquacks (Jun 5, 2010)

Hi People,

have a Homelite weeder tool with 2 cycle engine with ZAMA carb, which has the tamper proof limiter caps on both idle and high speed set screws. 

http://www.zamacarb.com/prodlist.html#C1U

Got the engine started, then warm it up, then press the throttle button to rev engine and it immediately stalls unless I quickly let off on the throttle button and let it just idle. 

Those 2 tamper proof tabs [pprevent one from backing them out the 2 full turns, after which, I understand, one can fine tune the low, then the high. Ive backed them out only about 3/4 turn each or so. Cant go any further. Cant figure it out. 

Unless my problem is other than that.......

Thanks!


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## Know It ALL (Nov 13, 2010)

Weak gas (old) or gummed up carb. Never leave gas sitting in a small engine. Too much oil will throw a 2 cycle out of tune. 
Go to a marine dealership and purchase some "power tune". Pull the fuel line and proceed to fill the carb. Must allow it to sit over night. Power tune is 10 times better than most carb cleaner.
Add fresh fuel and reset the mixture.
The adjustment locks were added because of people trying to run old or stale gas only to find that when they later added fresh gas the card had to be readjusted again.


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## Aggie67 (Dec 20, 2008)

I've been using Youtube for a while for small engine and carb repair. I redid my B&S snowblower motor/carb last winter off a youtube video, and my Stihl trimmer this past spring. Good info in there.

From an engine perspective, if your engine is dying when you open the throttle, could be a couple different things. Fuel delivery issues or air issues will cause it to die when you gun it. Bad gas is bad gas. Too much fuel can be caused by a bad carb. Too little fuel can be caused by a clogged jet or port. Too little air (actually, too deep a vacuum) can be caused by clogged tank vents. Too much air, by a bad gasket between the carb and the motor. Best "first" thing to check is to see if it runs with the gas cap off, which would peg the problem as a vent issue.

Carbs and carb kits are dirt cheap, too. Don't think about getting rid of the trimmer. My uncle gave me a "busted" blower about 10 years ago, and swore to high heaven when I had it running by the end of the day. I still have that beast.


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## noquacks (Jun 5, 2010)

Thanks, guys. Loks like I should yank the carb, and clean all, then use fresh gas. man, I always drain the gas when Im done with the stupid toy. Also, the gas is good enough for my 2 cycle chain saw (?).......

Thanks!


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## noquacks (Jun 5, 2010)

Know It ALL said:


> Weak gas (old) or gummed up carb. Never leave gas sitting in a small engine. Too much oil will throw a 2 cycle out of tune.
> Go to a marine dealership and purchase some "power tune". Pull the fuel line and proceed to fill the carb. Must allow it to sit over night. Power tune is 10 times better than most carb cleaner.
> Add fresh fuel and reset the mixture.
> The adjustment locks were added because of people trying to run old or stale gas only to find that when they later added fresh gas the card had to be readjusted again.


Thanks, Know it all....funny name. But this power tune elixir, biggest component is Naphtha. Is that the stuff that is supposed to be 10X stronger than carb cleaner? Cuz most carb cleaners are solvents way more powerful (toluene. acetone,hexane, etc). Not sure why carb cleaner wouldnt work....

Still, do you know exactly how I should set those plastic tabs to start? They , as you know, are not as clear cut as screw heads. One is red(High), other white(low). Should I start with both counterclockwise out then turn in to get best engine speeds for idle/high?

Thanks, Man


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## Know It ALL (Nov 13, 2010)

I found out about "quicksilver power tune" nearly 10 years ago from a marine mechanic friend. He was seriously hesitant about showing me his secrete formula to get boat engines back to life. In the past he would spend a few hours tearing apart carbs where as now he just pumps the system full of the power tune. Same money, just 1/4 the time. As you may know it is easy to leave gas in a boat carb over the winter and wind up with a clogged jet. Back in the 80s I remember one man who ruined his Johnson Stinger outboard engine because of a clogged jet. I have worked on and off around marine engines since 1978. I had an uncle (in law) who owned a glasstron boat dealership. 
I could tune your carb, but I will not guess as to your needle settings. In my line of work I get fined for making mistakes. Thanks to the epa.
Just trust me, powertune will make you smile.


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## liquidvw (Jun 8, 2009)

I have the same thing. First thing to do is to use a small screw driver to pry off those plastic caps. Once they are gone you should have 2 screws that you can use a flat head on. On mine, every 3 or 4 years, I remove the carb and open it up. Then I spray everything out with carb cleaner and put it back together. Then I set the carb using some instructions I found on the internet. You can google for that. Lastly use stable in your fuel year round and you should never have to drain it. Good luck. :thumbsup:


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## Wildie (Jul 23, 2008)

I had the same problem with the same Homelite model.
My solution was to put it out on the front curb. In the morning it was gone and so was my problem.


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## noquacks (Jun 5, 2010)

Yahoooooo!! Started up and runds great!!!

I put in fresh gas. Thats it. I adjusted the high speed screw slightly for max rpm's. The Homelite lives on! No need to put it out on the curb tonight........

Thanks, people.


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## romiir (Jul 27, 2011)

I registered on this forum to tell you guys you rock. I have a similar poulin/weedeater brand 2 cycle weed eater with zama carb that I also refused to throw away. (I also got this one free cause it wasn't working)

Anyways, last season I got it working again, and its been fine stored with fuel stabilizer, but this year I've been putting a couple hours here and there into it for weeks trying to get it to run correctly again, tore the carb apart today and put most of the rebuild kit into it and was still having trouble getting it to run, but after playing with it for a couple hours and replacing all the fuel screens/filters I got it priming properly again. Turned out the final problem was bad gas just as you guys mentioned above. At first I thought I wasted my money on some gas and oil that didn't need to be mixed since I have no other 40:1 equipment, but after letting it sit a bit it is running great now! Just like new! These things are cheaply built, but they are really easy to work on, and it seems only the carb has issues.

Anyways, sorry about pulling a dead thread up, but I just wanted to say thanks!


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## 95025 (Nov 14, 2010)

About 99% of the problems people run into with these 2-cycle engines is simple: FUEL SUPPLY

The orifices are so tiny that a shard of a blade of grass can plug up the carb. Or a bit of gas that has "varnished." Even ethanol blend gas can really jack some of them. Another frequent culprit is the "primer bubble" that many 2-cycle engines have. Over time it gets brittle, and develops hairline cracks that are hard to see, but let in air. When the primer bubble is sucking air instead of gas, you've got a non running engine.


Glad to hear you got your Homelite running again! :thumbsup:


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