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My SRM-230 had been running poorly the last few uses. Bogging and dying under full throttle once warm. Figured it was carb related but was due for a new plug and air and fuel filters, so figured the $18 kit with everything plus a new carb would get it all good as new.

Replaced everything tonight and now it won’t even try to fire up. Driving me nuts.

Lines are hooked up correctly…I see fuel flowing out down the overflow line when pressing the primer.

Plug is a bit wet but the piston doesn’t look soaked or anything. Plus you’d think if I flooded it, it would start while holding it full throttle with the choke setting off. It won’t even sputter on any combo of throttle or choke.

Waste of time but for giggles I tried the old plug (wasn’t in bad shape anyway) and same issue.

Fuel is brand new Trufuel

Doesn’t make sense that the high side adjustment would cause it to not even try to start but for the heck of it I tried all the way in, all the way out, and halfway and no luck no matter what.

Only thing I haven’t tried is putting the old carb back on. It’s a minor pain because the new carb came with a wrong size grommet so I have to swap the lines to the OEM correct grommet.

Curious if I’m missing anything or if it sounds like a bad new carb

Ezatnova said:

My SRM-230 had been running poorly the last few uses. Bogging and dying under full throttle once warm. Figured it was carb related but was due for a new plug and air and fuel filters, so figured the $18 kit with everything plus a new carb would get it all good as new.

Replaced everything tonight and now it won’t even try to fire up. Driving me nuts.

Lines are hooked up correctly…I see fuel flowing out down the overflow line when pressing the primer.

Plug is a bit wet but the piston doesn’t look soaked or anything. Plus you’d think if I flooded it, it would start while holding it full throttle with the choke setting off. It won’t even sputter on any combo of throttle or choke.

Waste of time but for giggles I tried the old plug (wasn’t in bad shape anyway) and same issue.

Fuel is brand new Trufuel

Doesn’t make sense that the high side adjustment would cause it to not even try to start but for the heck of it I tried all the way in, all the way out, and halfway and no luck no matter what.

Only thing I haven’t tried is putting the old carb back on. It’s a minor pain because the new carb came with a wrong size grommet so I have to swap the lines to the OEM correct grommet.

Curious if I’m missing anything or if it sounds like a bad new carb

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You could have ordered wrong carburetor, they could have shipped wrong carburetor, new $18 carburetor is defective, the carburetor wasn’t the issue. Also, pre-mix is better that Trufuel. Do some reading online about canned $20/gallon fuel vs pre-mix.

Now that I ave finished shaking my head and having a chuckle I will attempt to give you an answer
And you are not alone I get at least 5 of your kindred souls through the gate every month

My SRM-230 had been running poorly the last few uses. Bogging and dying under full throttle once warm. Figured it was carb related but was due for a new plug and air and fuel filters, so figured the $18 kit with everything plus a new carb would get it all good as new.

Click to expand...

Well that is your first mistake
You find the problem first then decide weather you are going to fix it or to replace suspect part
At this time of year there is a very good chance it was nothing more than a blocked muffler screen or outlet .
Other biggie is a carbon blocked exhaust port because you have been running with too much oil, too long or too thick line .

Replaced everything tonight and now it won’t even try to fire up. Driving me nuts.

Click to expand...

And it drives us nuts too because we now have the original problem plus to possibility that every new part is faulty

Doesn’t make sense that the high side adjustment would cause it to not even try to start but for the heck of it I tried all the way in, all the way out, and halfway and no luck no matter what.

Click to expand...

Makes perfect sense
The high jet does not come into play till around 3000 rpm and in many cases I set the Low speed ( and starting ) jet with the high totally closed when I am having difficulty getting a trimmer to start cold .
However what does not make sense is what the hell you are adjusting
You should have a Zama RB K 70a which as the name implies ( R= Rotary ) is a rotary valve carburettor which has a high speed just under a plug that is not readily accessible and rarely needs to be touched

Curious if I’m missing anything or if it sounds like a bad new carb

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Well a genuine RB k 70a is $ 75
A guaranteed aftermarket carb from an honest distributor is $ 50 and you paid $ 18 including air filter, fuel filter & fuel lines
So what do you think ?

Now Zama have the generic service manual for the RB series as a free download from their web page
Below I will upload the tuning proceedure for the SM235 which is basically the same as the 230
Finally do not spray carb cleaner inside any hole
The RB series has several internal check valves that are destroyed by carb cleaner .

Personally I would have done a compression test before ordering any parts. If the compression was under 100 psi I would scrape the engine as nearly all handheld two cycles require at least 100 psi to even try to start.

Installed a new carburetor?
Was the carburetor OEM or some generic model bought off of Amazon or EBay?
Were new gaskets installed on both sides of the intake block?
There was likely nothing wrong with the original carburetor.

People are quick to change out carburetors, when there is nothing wrong with the carburetor.

MParr said:

Installed a new carburetor?
Was the carburetor OEM or some generic model bought off of Amazon or EBay?
Were new gaskets installed on both sides of the intake block?
There was likely nothing wrong with the original carburetor.

People are quick to change out carburetors, when there is nothing wrong with the carburetor.

Click to expand...

when I disassembled things, there was only one gasket, which was between the carb and the intake hole on the engine. The kit did come with two gaskets but I know they usually do sometimes have extras for other fitments. Are you sure there is supposed to be a second gasket?

Just throwing out things.

Echo in question does not have a gasket on each side of the carburetor. The air box side has no gasket.


Also there several serial numbers breaks so you need make sure you using the correct IPL for parts even they all use the same carb.

bertsmobile1 said:

Now that I ave finished shaking my head and having a chuckle I will attempt to give you an answer
And you are not alone I get at least 5 of your kindred souls through the gate every month

Well that is your first mistake
You find the problem first then decide weather you are going to fix it or to replace suspect part
At this time of year there is a very good chance it was nothing more than a blocked muffler screen or outlet .
Other biggie is a carbon blocked exhaust port because you have been running with too much oil, too long or too thick line .

And it drives us nuts too because we now have the original problem plus to possibility that every new part is faulty

Makes perfect sense
The high jet does not come into play till around 3000 rpm and in many cases I set the Low speed ( and starting ) jet with the high totally closed when I am having difficulty getting a trimmer to start cold .
However what does not make sense is what the hell you are adjusting
You should have a Zama RB K 70a which as the name implies ( R= Rotary ) is a rotary valve carburettor which has a high speed just under a plug that is not readily accessible and rarely needs to be touched



Well a genuine RB k 70a is $ 75
A guaranteed aftermarket carb from an honest distributor is $ 50 and you paid $ 18 including air filter, fuel filter & fuel lines
So what do you think ?

Now Zama have the generic service manual for the RB series as a free download from their web page
Below I will upload the tuning proceedure for the SM235 which is basically the same as the 230
Finally do not spray carb cleaner inside any hole
The RB series has several internal check valves that are destroyed by carb cleaner .
View attachment 65606

View attachment 65607

Click to expand...

Thanks for the info. Forgot to mention the exhaust port is clear and ok.

What I WAS missing was the fact that there was an idle mixture adjustment . It was alllll the way out from the factory. Only have 2 minutes and have to run out for the day but I quickly put that screw in all the way and backed it off a touch and it fired right up in 3 pulls! Rough idle but I’ll get that sorted later with tuning and report back.

Well that is a good start
Follow the instruction to the letter or you will end up with a hole in the piston in no time flat
Also note the bit at the end about having line hanging out of the head when you do the final tune up
THIS IS VERY IMPORTANT
So now we know there may not be blockages strangleing the engine hen your original problem is typical of a hard or punctured metering diaphragm
After that the next most common fault that causes those symptoms is a bad needle height, but these should not change in use
When you come to the final tune, turn the H needle out till it stalls rich and do the opposite till it stalls lean
Listen carefully and remember the different sounds of too rich & too lean.

And don't be surprised if you can not get the cheapis carb to run right no matter what you do a lot of them are defective which is why they are so cheap as the vendor bought them for the scrap metal valuse whic is about 4¢ each

Ezatnova said:

when I disassembled things, there was only one gasket, which was between the carb and the intake hole on the engine. The kit did come with two gaskets but I know they usually do sometimes have extras for other fitments. Are you sure there is supposed to be a second gasket?

Click to expand...

I just got through repairing my personal SRM 225. I purchased the Echo YouCan Kit to replace the fuel lines, fuel tank grommet, primer bulb, fuel filter, fuel cap gasket and vent filter. I also replaced the intake gaskets (sold separately). There was one gasket on each side of the intake block. One gasket went between the carburetor and the intake block, the other went between the intake block and the engine. That kit, along with an air filter, spark plug, and intake gaskets fixed all of my problems. The spark arrester screen was clean. No fuel mix leaking. No bogging. It runs like new.

StarTech said:

Just throwing out things.

Echo in question does not have a gasket on each side of the carburetor. The air box side has no gasket.
View attachment 65608

Also there several serial numbers breaks so you need make sure you using the correct IPL for parts even they all use the same carb.
View attachment 65609
View attachment 65610

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It’s very important to replace #11 and #14 when you are in there. Make sure those gaskets are oriented correctly.

Ah, I never took off the intake block to see gasket #14. Now I see in the diagram it matches the gasket I have left sitting on my bench lol. I’ll replace it when I can, but, good news for now is after tweaking the low and the high mixture screws it’s running great.

Couple other things

- it stinks after I ran it for 5 minutes and shut it down and it puffing smoke from the exhaust. It is a nasty smell similar to after I’ve installed new exhausts on cars and run them hard. I’m hoping this is just the new carb breaking in. It does not smell like oil or fuel. I think I remember the same smoke happening when I replaced the carb in my echo blower.

- one thing that I didn’t find easily on YouTube or google is the throttle cable length adjustment. When I installed the new carb, the cable would only pull the butterfly about 90% of the way. I noticed the long 8mm hex shaft piece that the cable went through right up at the top where the barrel on the cable latched in. I turned that shaft counter clockwise and it snugged up the cable so now I get 100% throttle movement.

curious to see how it does when I really use it next. Seems much improved and running strong in the quick test.

If the plug is wet it is flooded. Take the plug out, let it sit overnight and put it back in. Try again without priming it. Maybe rebuild the original carb if the carb listing is indeed RB 70 https://www.carbtech21.com/ProductDetails.asp?ProductCode=RB-070