Echo srm2100 engine flooding

Snapperfreak

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I bought my srm2100 new almost 20 years ago. It's the only item out of all my equipment that was purchased new. It's always been well maintained and just used at home. But a frequent problem, even when it was relatively new, was that the cylinder would tend to flood with fuel making it impossible to start. It's always leaked fuel (or maybe oil, seems thick) out the muffler and other places around the engine making it really gunned up after a few uses. A couple years ago I replaced the carb with a new sams carb, new fuel lines and filter and air filter all at once to see if that helped. Since the new carb was installed its only seen full synthetic fuel. Now it won't start even if I pull the plug, dry it off and put it back in. Floods immediately. Any help would be appreciated. Thanks.
 

Snapperfreak

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Meant to say gunked up. And forgot to mention I love the trimmer and would rather fix it that by a new one.
 

Snapperfreak

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Jeez sorry about all the misspelled words. Zama carb, not sams carb.
 

bertsmobile1

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Could very well be a poor spark.
If it don' spark, the engine will wet the plug and unburned fuel & oil will condense in the muffler
After dark slip out into the shed and check for spark, they are very hard to see in the daylight.
Do a compression test, you should see 75 psi or greater if you have a good tester with the appropriate adapters.
The on/off switches are notoriously problematic.
Also because they spin so fast the kill wire fretts through then grounds out on the engine.
To test it, tip out all of the fuel, disconnect the switch at the coil start the trimmer.
You tip the fuel out because without the switch connected you can not stop it and pulling the plug can be difficult on some models.

You said you look after it , does that include removing the spark arestor screen and cleaning it regularly /
Also check the amount of carbon build up around the exhaust port.
If you have been running it with too much oil there will be a big build up which can be enough to choke the engine.
 

Snapperfreak

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Good info, thank you. I will look into if it has spark and the kill switch issue. I don't have a compression tester, may have to pick one of those up, but it feels like it has just as much compression as ever. So odd, it was running perfectly the last time I used it a few weeks ago until this latest headache. The spark arrestor I have taken out and it was not plugged up but, just to see if it helped, I left it out. No difference. But it sounds like the spark or kill switch may very well be the culprit here. I have not checked either of those yet. Thank you so much for the info sir.
 

Snapperfreak

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Forgot about the exhaust port you mentioned...when I had the spark arrestor and muffler off I checked in there. Totally clean and the piston clean as well. Guess I'm doing something right. I've probably looked after it more than any other mower I have. Besides the non-ethanol 93 octane synthetic fuel, I always store it empty. Been in love with this trimmer since I bought it. The 2400 is really just a back up, although I want to get it running right just the same. Both are my current projects.
 

Snapperfreak

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Just got home and couldn't wait to check things out and all checks out well. Spark is good and on/off switch is good also. Don't have a compression tester but it feels just as it always has. I guess my last resort is to rebuild this new carb, it has been in there a couple years and maybe the needle has become an issue. Pretty frustrated here. Everything looks good but it just does not want to start. Thanks again for your help.
 

cpurvis

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I have the same trimmer, just a few years older. Still starts and runs good.

Mine slobbered oil out the exhaust, too, but I ran too rich of oil mixture for a long time. Haven't noticed it doing that as bad since running 50:1 as the book calls for. The spark arrestor screen has caused no more problems since I threw it away.
 

Snapperfreak

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I've kept the mix at 50:1, what's weird is even when it was new the spewing of oil thing was going on. It ran fine otherwise though. Ya I yanked the arrestor and tossed it too. I have a carb kit for it so I will take it apart this weekend and replace the diaphrams and gaskets and check the needle. Not hopeful but if still no luck I'll spend the $22 to have the shop look at it one last time. If they can't figure it out then screw it im buying a stihl FS94R.
 

bertsmobile1

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Blue smokes have 2 compressions.
1 Primary compression ( in the crank case)
2 Secondary compression ( above the piston )
However is the primary is bad the engine runs lean and wears the rings quicker than it should .
Low primary compression makes the engine really had to start.
Modern fuel is highly conductive at cylinder pressure and if the plug has fouled once, they can be very hard to clean.

You might like to try a new plug, or put your plug in your mower or some other engine and put it in the Echo hot to prevent fuel condensing on the plug & extinguishing the spark.
If it is fouls the plug then either it passing way too much fuel, the choke is cutting off too much air ot the spark is at the wrong time or the spark is not jumping the gap
 
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