# Echo SRM-210 Removing the fan case



## RVC (Aug 14, 2009)

Good evening, everyone.

I want to check the gap between the coil and the flywheel on this trimmer but I can't figure out how to get the fan case off. I don't have a service manual but I do have the on-line parts diagram and it is not very helpful. If anyone could help I would appreciate it.

Thanks.

RVC


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## 30yearTech (Sep 14, 2006)

Coil air gap can't really change, so there is no real reason to check. The fan case is held on with 4 Allen head screws, you will need a 3 mm wrench to remove them. There are a couple of alignment pins that kind of also keep the cover from coming off, so you will have to pry on the case a little to get it off.


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## RVC (Aug 14, 2009)

Thank you. I have all the allen bolts off. It's those alignment pins you mention that are the problem. Can't seem to get the case off them. Guess I'll need a bigger screw driver.

I appreciate your help.

RVC


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## RVC (Aug 14, 2009)

Hello again. I'm still working on the same SRM-210. I took your advice and did not try to take the fan case off. As it turns out it has sufficient spark to run.

I recently installed a new ZAMA RB-K75 carb on the trimmer. It will run for a second if I pour a little gas into the cylinder and replace the spark plug. It won't run with just the carb after that.

I'm not sure what to try next and would appreciate some advice.

Thank you.

RVC


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## usmcgrunt (Sep 16, 2007)

Did you replace or at least check to make sure the fuel lines are both good with no cracks and a clean gas filter?Are you sure you put the lines back on correctly?The carb will not draw fuel if the lines are reversed.


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## RVC (Aug 14, 2009)

Yep. The fuel lines, filter and the rubber grommet in the tank they both pass through are new. As far as the fuel lines being reversed, I'm pretty sure they are not. There are two of them. The larger yellow line is plugged into the larger tube on the carb and the smaller black line is plugged into the smaller tube on the carb. Is this correct? Is the yellow line the supply which the filter is supposed to be connected to?

Thanks for your reply.

RVC


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## Rentahusband (Aug 25, 2008)

Are you getting gas in the primer bulb when you prime it?


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## 30yearTech (Sep 14, 2006)

RVC said:


> Yep. The fuel lines, filter and the rubber grommet in the tank they both pass through are new. As far as the fuel lines being reversed, I'm pretty sure they are not. There are two of them. The larger yellow line is plugged into the larger tube on the carb and the smaller black line is plugged into the smaller tube on the carb. Is this correct? Is the yellow line the supply which the filter is supposed to be connected to?
> 
> Thanks for your reply.
> 
> RVC


The yellow line is the return hose from the carburetor to the tank. The black hose should have the fuel pick-up filter on it and is the supply hose. If the lines are hooked up properly you should be able to see the fuel flow back into the tank when you push on the bulb on the carburetor.


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## RVC (Aug 14, 2009)

Thanks all. Sorry to have two threads going on this same topic. Interest seemed to have died out on this thread which is why I started the new one.

If what you say is correct, and I have no reason to doubt it, then I have my lines backwards. Doesn't seem logical as the yellow line is larger and seemed like it should go on the larger tube on the carb. Same with the black one being smaller and going on the smaller tube. Never the less I'll take your word for it and swap them in the morning.

I really appreciate your help here guys. I'll let you know how it turns out.

RVC


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## dawgpile (Apr 28, 2008)

Hello RVC

I'm pretty sure my Echo trimmer is an SRM-210 also. I'll get home from work today in the early afternoon(eastern time), and if so, I'll check and photograph the fuel lines for you and post here!

Just as an fyi from my own servicing experience, you can't always make the assumption about size of the fuel line vs size of the pipe on the carb. What would appear to make common sense is sometimes just not the case!

Stay tuned...


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## dawgpile (Apr 28, 2008)

*Echo SRM-210 fuel line pic*

My unit is an Echo SRM-210

As you can see from the photo, there are 3 fuel lines in view.

- The clear one on the left of the primer bulb is the return line to the tank. It extends into the tank about 0.5" to 1.0" [just like the black vent line discussed below]
- The black one on the right of the primer bulb is the supply line which comes from the tank. This one extends into the tank and has the filter/weight attached.
- The third black one from the tank goes up to a vent. It extends into the tank about 0.5" to 1.0".

Fuel comes from the tank into the primer through the black fuel line on the right of the bulb. It exits the primer bulb through the clear line on the left of the bulb and returns into the tank. Since the fuel cap is NOT vented, the third line is required to vent the tank to atmosphere.

I hope this helps! Good luck. 

(FWIW, this unit also has a ZAMA carb.)


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## RVC (Aug 14, 2009)

I appreciate the picture and the time spent taking and posting it. I'll check mine out in the morning.

RVC


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## RVC (Aug 14, 2009)

Well as it turns out my lines were going to the wrong places on the carb. Many thanks to dawgpile for your pictures and description and others for suggesting the same thing. So now I've switched them and the thing still doesn't run, but today has been hectic and I haven't tried very hard. Maybe tomorrow.

I really appreciate all the input and help to this point. I'll let you know how it turns out.

RVC


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## dawgpile (Apr 28, 2008)

RVC

If you now see fuel cycling back through to the fuel tank when you are depressing the primer bulb a few times and no fuel is leaking out anywhere around the primer bulb and carb, then as geogrubb mentioned, I'd be looking for an air leak on the intake side. When you replaced the carb, did you check the two 5X20 bolts that hold the intake insulator to the head for tightness? They are underneath the gasket that's between the carb and the insulator. Likewise did you inspect and/or replace the gasket between the carb and the insulator? I can't recall if you can put that gasket on backwards and block the pulse port. Obviously, it needs to be oriented properly for pulse pressure/vacuum to make it to the carb.

When you tried to start it after proper routing of fuel lines, with the unit choked, did it ever pop even once? After several pulls, I'd consider examining the plug to determine if fuel is indeed making it in. If it isn't, then I'd focus on the intake side for obvious reasons but if it is, then I'd consider examining the exhaust side and check for blockage. Pull the muffler and check the exhaust port and the muffler screen itself and look for carbon buildup.

Let us know how you make out!


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## dawgpile (Apr 28, 2008)

Finally, another potential source of leakage is the where the head attaches to the two halves of the crankcase. Said another way, if there is a leak between the two halves of the crankcase and/or between the head and the crankcase, that will also cause no/low fuel draw. This problem is less likely, but certainly can occur. You can try and grab the plug in one hand and hold the rest of the unit in the other and rock the plug to see if you see or feel any play or looseness between the head and the case. Likewise, you try and do the same with the case halves, although it's easier said than done! The more definitive way would be to do a pressure leakdown and a vacuum leakdown test of the unit. However, this can be difficult if you don't have the means to properly block off the intake and exhaust ports of the head.

BTW, I don't recall from your previous posts if the problem that caused you to replace the carb in the first place cropped up all of a sudden after the unit was working properly, or if you just tried to start it at the beginning of this new season after sitting over the winter. You might comment on that as well.

Good luck!


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## RVC (Aug 14, 2009)

Good evening. I apologize for the delay in getting back to you. Weekends for me are generally filled with many priorities higher than weed hackers.

To answer your questions, the trimmer was given to me by a friend to see if I could fix it for him. I don't know any of the history of it other than it wouldn't crank when I got it.

I can now see fuel returning to the tank when I press the primer. The intake insulator is correctly installed with gasket in the correct location. The gasket between the carb and insulator is new and is also installed and tightened correctly. Incidentally the gasket can be installed either way and still function correctly. It cannot be installed upside down, however. The carb is new, as has been mentioned. The needle came without the protective plug installed over it. Could there be a problem with the needle not correctly set?

When I tried to crank the thing it did not fire at all and I gave it a bunch of pulls. I have not tried any of the suggestions you mentioned. Time is a factor but I hope to work on it in the morning.

Thanks again for your help and input. I'll get back to you tomorrow.

RVC


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## dawgpile (Apr 28, 2008)

The next time you try to start it, first remove the plug and make sure it's clean and dry. Then reinstall it, prime 5 or 6 times, choke it and try starting. After several pulls, and no starting, remove the plug and inspect. See if it's wet.

If it is, let us know and we can go down that path. If it's not, you can try one other simple test, albeit temporary, to check for cylinder related problems. With the plug out, squirt a small amount(a teaspoon at most) of 30wt oil in the plug hole and slowly pull the starter cord. The goal is to try and coat cylinder walls and piston ring with oil to provide a temporary air seal and create more vacuum when trying to start. Replace the plug and try again.

If this caused it to fire, however temporarily, it's time to check for cylinder/piston/ring damage. Remove the muffler and turn it over until you can see in the cylinder. Check for scoring. Slowly turn it over and look at the piston and ring area as they pass the exhaust port. See how scored/galled/grooved the piston and ring are. Typically, the scoring is the most severe on the exhaust port side of the cylinder, so peering in the exhaust port alone may not reveal a big problem on the opposite or intake side of the cylinder. If you see scoring on the intake side of the cylinder wall, that's usually a pretty bad case! The hottest part of the cylinder is the exhaust side and that is where scoring usually happens. That's why it's important to inspect the piston/ring as it passes the port.

If you discover cylinder/piston/ring damage, you just have to decide how much money you want to put into the machine. New comparable units are running about $200. You've already bought a carb. Check ebay. I just priced a new cylinder and piston kit for an old Craftsman(Poulan) unit at $55 and that was more than my customer wanted to spend on it. If you decide to give up on it, pull that new carb off and put it on ebay. That and other parts will get your money back!

As before, keep us posted!


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## RVC (Aug 14, 2009)

Well, I pulled the exhaust, and the piston and ring were smooth as a baby's behind with only slight discoloration of the piston. I was going to move on to putting some oil in the combustion chamber like you recommended to try to bring up the compression but decided to try squirting some gas in there one more time. I replaced the plug and the thing fired up on the first crank and this time kept running. I have no idea what I may have done but there is the sneaking suspicion that I didn't have the spark plug wire on all the way. Kind of embarrassing if that was the problem but at least it finally runs.

One more question before I move on. What is the single needle for?

Thanks for your help there dawgpile and others. It is very much appreciated.

Rick


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## dawgpile (Apr 28, 2008)

Rick:

Glad to hear you got it going. I'm sure all of us have stories like yours so don't sweat it! You got it running and that's what counts.

I'm not exactly sure what single "needle" you are referring to so I'll take a guess. There is an adjustment for setting the idle speed. Is this what you are referring to?

If you don't have an Op Manual for it, you can find it here:

http://www.echo-usa.com/Support-Help/Technical-Documents.aspx?s=SRM-210&c=en-us

They detail this adjustment and other info. Parts lists are there also fyi.

Happy Trimming!


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## RVC (Aug 14, 2009)

Thanks for the Op Manual.

Regarding the needle, on the picture you provided a few days back, just below the primer bulb is a white piece of plastic. Just to the left of that is the needle in the carb body. From the factory it has a plastic protective plug over it. On my new carb the needle is exposed recessed back in there and the plug is provided to cover it presumably when the carb is correctly adjusted.

Thanks again!

Rick


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