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SRM 225 won't rev up.

#1

G

Geardrive1

Hello everyone, I'm new to this forum. I have a problem with an Echo srm225 trimmer.

It's about 7 years old and I use it about twice a month. I always empty the tank and idle untill it dies.

About 2 years ago it started running bad, so I bought a gasket kit and took apart the carb blasted it with brakekleen and air also drilled out the plug to adjust the air and fuel. It ran fine till about February of this year. So, I finally ordered a new carb from Amazon and it ran great till last month.
The problem was that I would have to keep the choke way up to keep it running. Till it would not start period. So I ordered another carb. (different brand). I installed it, changed the air filter and the fuel filter and removed the muffler soaked it in solvent overnight and cleaned it, changed the fuel lines the spark plug. and it does the same thing.
It idles great, and it somewhat revs up when it is dead cold but as soon as it warms up it won't rev up. This carb has a plug on the air to fuel mixture screw so I did not attempt to remove it in case I have to return it.
I removed the gas cap also.
It will idle for great for a long time but I can't get to rev up it just stumbles wherever ever the choke lever is at.

Thank You , any thoughts would be greatly appreciated.


#2

R

Rivets

Have you check to see if the spark arrester is not plugged?


#3

StarTech

StarTech

This what you get by buy China clones. But as Rivets suggest check the spark arrester first.

But just for fun which of the 16 serial breaks for the SRM-225, 14 serial breaks for the SRM-225i, 3 serial number breaks for the SRM-225SB, or the 6 serial number breaks for the SRM-225U is it? And do you have tach and tape measure for tuning?


#4

G

Geardrive1

I don't know what a tach and tape measure is for tunning, the spark arrester is long gone.


#5

H

hlw49

Did you check the exhaust port in the cylinder to make sure it is open?


#6

StarTech

StarTech

Geardrive1 said:
I don't know what a tach and tape measure is for tunning, the spark arrester is long gone.
Click to expand...
Well there is specific tuning instructions from Echo requiring specific string lengths and rpms. Strings length spec is for proper loading of the engine during the tuning process.

These specs can be different depending the model and serial numbers as there were four different carburetor used on this and the tuning is done with a Speed Feed 400 trimmer head. The main adjustment to set the idle mixture rich for a specifed rpm drop from max idle speed.

Here is just a sample what the Echo/Shimdaiwa should using to tune these engines.
1694169424304.png

So there is more involved than what the average user knows. Without proper adjustment engine damage can occur. Specially if you run with the mixture too lean.


#7

Tiger Small Engine

Tiger Small Engine

StarTech said:
Well there is specific tuning instructions from Echo requiring specific string lengths and rpms. Strings length spec is for proper loading of the engine during the tuning process.

These specs can be different depending the model and serial numbers as there were four different carburetor used on this and the tuning is done with a Speed Feed 400 trimmer head. The main adjustment to set the idle mixture rich for a specifed rpm drop from max idle speed.

Here is just a sample what the Echo/Shimdaiwa should using to tune these engines.
View attachment 66643

So there is more involved than what the average user knows. Without proper adjustment engine damage can occur. Specially if you run with the mixture too lean.
Click to expand...
Hopefully you didn’t throw away the OEM carburetor. Clean it thoroughly and replace metering diaphragm. So you are going to return a $20 carburetor that has been used? Take the low and high plugs out if necessary are adjust the darn thing. The fact that you know those hidden screws are there is amazing to me. Pull the muffler and check the condition of the piston, rings, and cylinder.


#8

R

Rivets

The spark arrester is under the muffler, not on the outside. Did you remove the muffler to check it. When you remove the muffler you can check the exhaust ports as suggested. This site shows the location. https://www.partstree.com/models/srm-225-echo-string-trimmer-sn-s03912001001-s03912999999/exhaust-5/


#9

StarTech

StarTech

Rivets, The spark arrester when present is under a deflector cover; NOT under the muffler. You got it in your mind wrong. On the diagram it is held by 5 screws. All the OP had to do is remove the engine shroud to access it. The two main muffler screws are never touched unless the muffler is being removed. These 5 screws can be a pain to remove depending how rusty things are.

Now there are time the defector can be removed without removing the shroud but it is much with the shroud removed.


#10

R

Rivets

Star, you are correct, haven’t finished my first cup of coffee yet. Sorry about the terrible post.


#11

StarTech

StarTech

OR in my case the first pot....Just trying to figure a way to remove a split retainer on a Gravely spindle. Just like to know what bearing were used. I already knnow I can't the retainer so it is a new spindle. Now just debating if OEM or aftermarket one. Reading reviews and about 10% are bad so far. At least Rotary and Stens gives an one year warranty on them. Trying to find out what Ariens/Gravely warranty is. Still $200+ is a lot for the customer to pay for either one. I got time as I having to wait on bushings and spacers for the deck otherwise.


#12

R

rutbuster1

Geardrive1 said:
Hello everyone, I'm new to this forum. I have a problem with an Echo srm225 trimmer.

It's about 7 years old and I use it about twice a month. I always empty the tank and idle untill it dies.

About 2 years ago it started running bad, so I bought a gasket kit and took apart the carb blasted it with brakekleen and air also drilled out the plug to adjust the air and fuel. It ran fine till about February of this year. So, I finally ordered a new carb from Amazon and it ran great till last month.
The problem was that I would have to keep the choke way up to keep it running. Till it would not start period. So I ordered another carb. (different brand). I installed it, changed the air filter and the fuel filter and removed the muffler soaked it in solvent overnight and cleaned it, changed the fuel lines the spark plug. and it does the same thing.
It idles great, and it somewhat revs up when it is dead cold but as soon as it warms up it won't rev up. This carb has a plug on the air to fuel mixture screw so I did not attempt to remove it in case I have to return it.
I removed the gas cap also.
It will idle for great for a long time but I can't get to rev up it just stumbles wherever ever the choke lever is at.

Thank You , any thoughts would be greatly appreciated.
Click to expand...
If the spark arrestor isn't clogged, most likely the carburetor just needs adjustment. If the arrestor is clogged you can either clean it or toss it. I toss em. They're not needed. If the carb screws are blocked with a cap, take em out to get to the adjustment screw. You don't have to drill em out.


#13

R

rutbuster1

StarTech said:
This what you get by buy China clones. But as Rivets suggest check the spark arrester first.

But just for fun which of the 16 serial breaks for the SRM-225, 14 serial breaks for the SRM-225i, 3 serial number breaks for the SRM-225SB, or the 6 serial number breaks for the SRM-225U is it? And do you have tach and tape measure for tuning?
Click to expand...
There's nothing wrong with the China clones. I use em all the time and have no issues with them. I mainly us Hipa products. One customer just had to have an OEM carb on his chainsaw. I ordered it, received it, looked it over and what do you know? Where was it made? "Made in China." Practically everything is made in China nowadays. Sad, but true.


#14

H

hlw49

Check the exhaust port as well they can clog too.


#15

M

MParr

I have the same trimmer. It’s older than yours. It still has the original carburetor. The only things that I’ve done to it were to change the primer bulb, the fuel lines and their filters, the fuel tank grommet, air filter, and the two gaskets on both sides of the intake manifold block. I replace the plug regularly. The spark arrester was clean It runs as good as it did New.


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