Echo SRM225

[goulgetter88]

Hello Everyone!!

I am not a professional and a novice at best. I am working on an ECHO SRM-225. The only history I have on this weed eater is my sister in-law had it and it hasn't started since she had it. So with that being said it will not start. Will not hit at all no matter how many times you pull the string. Here's what I have checked/done so far. It has good fuel in it with now water in it. It primes every time and fuel is getting to the plug. Checked the plug and it is getting wet. I did replace the Autolite that was in there with the correct NGK it calls for. Its getting spark I know because I have tested it and seen its getting spark. So moving on to the next thing I did a compression check. With the throttle wide open and pulling the string several times the gauge only reads 60-70 psi. That's not enough to start it I assuming. Pulled the muffler off just to check the spark arrestor screen and to look at the piston ring. The screen was a little nd I cleaned it off. Looking at the piston through the exhaust port, and it looks clean and the ring looks good from what I can see. With that being said where do I go from here???? I've been down this road with a Craftsman leaf blower and replaced all kinds of things including the piston ring and that blower still will not start and has the same compression issue .

I'm looking for any and all advise and again I am not a professional. I really want to figure this out on my own and fix it.

[38racing]

Try a bit of carb cleaner into the air intake and pull a few times and see if it fires briefly.

[goulgetter88]

Try a bit of carb cleaner into the air intake and pull a few times and see if it fires briefly.

Tried it hasn't worked yet sadly

[bgsengine]

60-70 PSI is no where near enough compression for these to start - Minimum is 110 PSI before it'd even "think" about starting - If ring "looks" good, then likely it may be stuck ring - (Or, if it is high hours and/or spent any time with lack of maintenance or cheap aftermarket air filter (which would not be a surprise since you found an autolite plug in it) in dusty conditions, ring could have rapidly worn down.)

[goulgetter88]

60-70 PSI is no where near enough compression for these to start - Minimum is 110 PSI before it'd even "think" about starting - If ring "looks" good, then likely it may be stuck ring - (Or, if it is high hours and/or spent any time with lack of maintenance or cheap aftermarket air filter (which would not be a surprise since you found an autolite plug in it) in dusty conditions, ring could have rapidly worn down.)

See I have run into these same conditions before with a craftsman blower motor. Put a piston ring in and it still does the same thing and has low compression. I just don't want to buy more parts tear it down replace the ring and be back at square one. If you think it is a stuck ring then that's what I will go with. I do not want to be a parts replacer , but be able to diagnose the fix it properly. You have confirmed my fears of what I was thinking. Would still like other opinions as well.

[Skywatcher]

Hi GG88

Do you have good crankcase compression to properly feed the cylinder? With sparkplug out, throttle and choke both wide open, do you hear a crisp Pop from the sparkplug hole when you spin the engine over with the starter cord? (Be sure to have ignition switch off or plug lead grounded so you don't fry the coil).

As for priming these little engines, I feel that carburetor cleaner is too drying and will remove essential lubricating oil from the internal parts. I always use a 40:1 premium (91 octane)two cycle fuel mix in a squirt bottle for priming purposes. Let us know what you find,

Sky

[KE4AVB]

You probably will upon disassembly find that the cylinder plating is worn through in places. As mention a stuck ring is a possible but this can be checked for by removing the muffler. When this is done you can also you get a view of piston for sorcing and the intake side of the cylinder wall. If piston is scored the engine has straight gassed then it will need to be short blocked.

If so short blocking (PNC) replacement is the best way to go but it is fairly expensive. Just look up SB1096 for pricing usually around $100 -$125 depending where get the parts.

[goulgetter88]

You probably will upon disassembly find that the cylinder plating is worn through in places. As mention a stuck ring is a possible but this can be checked for by removing the muffler. When this is done you can also you get a view of piston for sorcing and the intake side of the cylinder wall. If piston is scored the engine has straight gassed then it will need to be short blocked.

If so short blocking (PNC) replacement is the best way to go but it is fairly expensive. Just look up SB1096 for pricing usually around $100 -$125 depending where get the parts.

Hi GG88

Do you have good crankcase compression to properly feed the cylinder? With sparkplug out, throttle and choke both wide open, do you hear a crisp Pop from the sparkplug hole when you spin the engine over with the starter cord? (Be sure to have ignition switch off or plug lead grounded so you don't fry the coil).

As for priming these little engines, I feel that carburetor cleaner is too drying and will remove essential lubricating oil from the internal parts. I always use a 40:1 premium (91 octane)two cycle fuel mix in a squirt bottle for priming purposes. Let us know what you find,

Sky

So I wanted to answer the one question and then give my findings for today.

Skywatcher: Yes there is a noise when the plug is out and holding the throttle open. Is it a popping noise. I guess you could call it that lol. I don't think continuing to pour fuel down the carb is going to make a difference. Just my opinion and I could be wrong. That's why I am here.

KE4AVB: I removed the muffler again and looked at the ring and the ring "looks good". However there was a little bit of discoloring brownish in coloring under the ring in one stop. I can barely see down the exhaust port and I will post a picture of what I saw if I can. Looks like possible scoring on the intake side of the cylinder wall.

Please more advise and things to try are good. I am here to learn how to diagnosis things. I take every ones opinion seriously.

[bgsengine]

I can barely see down the exhaust port and I will post a picture of what I saw if I can. Looks like possible scoring on the intake side of the cylinder wall.
.

Ooohh if you can barely see - By any chance do you mean it is a heavy black build-up? Using poor quality 2-stroke oil can lead to excess carbon build up that blocks exhaust port.. what to do in that case: remove plug and roll engine over until piston is just about top center, and then use a wooden or plastic dowel (nothing of sharp metal) and scrape away carbon until you get to bare metal on the exhaust port.. if you have a lot of carbon build-up in the port it can cause your problem - once you finish cleaning out the carbon have the port side down and see if you can squirt a bit of 2-cycle gas to flush away chips then roll it a couple times , leave muffler off, squirt a bit of gas into spark plug hole, install plug and ignition wire and see if it will fire that fuel charge (it may even start and run) - don't run more than a few seconds with muffler removed.. If it does run then, put muffler back on and see if it will still run - if not, and you did have a lot of carbon, it is possible the muffler's catalyst element is clogged...

Running them at less than full throttle when in use can lead to excess carbon build-up and catalyst element clogging since there's not enough heat generated at part throttle for things to work as designed...

In any case, if the exhaust port is heavily clogged with carbon it'd need to be cleaned up as normal maintenance anyhow..

[goulgetter88]

I can barely see down the exhaust port and I will post a picture of what I saw if I can. Looks like possible scoring on the intake side of the cylinder wall.
.

Ooohh if you can barely see - By any chance do you mean it is a heavy black build-up? Using poor quality 2-stroke oil can lead to excess carbon build up that blocks exhaust port.. what to do in that case: remove plug and roll engine over until piston is just about top center, and then use a wooden or plastic dowel (nothing of sharp metal) and scrape away carbon until you get to bare metal on the exhaust port.. if you have a lot of carbon build-up in the port it can cause your problem - once you finish cleaning out the carbon have the port side down and see if you can squirt a bit of 2-cycle gas to flush away chips then roll it a couple times , leave muffler off, squirt a bit of gas into spark plug hole, install plug and ignition wire and see if it will fire that fuel charge (it may even start and run) - don't run more than a few seconds with muffler removed.. If it does run then, put muffler back on and see if it will still run - if not, and you did have a lot of carbon, it is possible the muffler's catalyst element is clogged...

Running them at less than full throttle when in use can lead to excess carbon build-up and catalyst element clogging since there's not enough heat generated at part throttle for things to work as designed...

In any case, if the exhaust port is heavily clogged with carbon it'd need to be cleaned up as normal maintenance anyhow..

There is some carbon build up in the port. However is it not enough to block it I believe. What I meant was my eyes are not that great (I wear glasses and still have trouble seeing small things) and that I didn't have enough light to see in the port so go. I will try this and see what happens. I am not giving this much hope to work as everything else has failed to work so far. Ill be in touch tomorrow.

Id love to know how to insert an image on here to show the exhaust port