Echo HC-1500 hedge trimmer has always run great. Just tried to fire her up after sitting 5 months. Started and idled ok. Also accelerates to high speed ok but then surges badly. Put in fresh mix and new plug, same performance. Fuel filter and supply line ok. Took carb apart but did not do any deep cleaning. Diaphragm looks ok. Maybe weak ignition or maybe needs a carb rebuild. Any suggestions? Thx.
Echo won’t run on high speed
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The diaphragm can take a set & get brittle, less fuel delivered, no consistent high speed operation.
There are two diaphragms, one that moves the fuel, another that acts on the inlet needle & seat that fills the fuel chamber. They can both 'take a set' & cause hunting.
A kit with fresh diaphragms may solve it, if there isn't dirt causing the inlet needle from closing.
There are two diaphragms, one that moves the fuel, another that acts on the inlet needle & seat that fills the fuel chamber. They can both 'take a set' & cause hunting.
A kit with fresh diaphragms may solve it, if there isn't dirt causing the inlet needle from closing.
I've had luck with spraying a bit of seafoam, a bit, for a minute or two, WOT.
The carbs are cheap and easy to replace.
The carbs are cheap and easy to replace.
The Mantis tiller has an Echo engine. Had to replace the carb evry spring. I down loaded a PDF for the owners manual. It says to dump all the fuel and run the carb dry after EVERY use. I have the carb set a bit rich. It doesn't need to be choked for a cold start.
My first thought is that you need to adjust the high speed mixture screw/needle, but you probably don't have one.
Originally Posted by das_peikko
My first thought is that you need to adjust the high speed mixture screw/needle, but you probably don't have one.
I do have an hi speed adjusting needle. It has no effect on the surging.
My first thought is that you need to adjust the high speed mixture screw/needle, but you probably don't have one.
I do have an hi speed adjusting needle. It has no effect on the surging.
Originally Posted by gman2304
My Echo blower would do the same. A new air filter fixed it.
I ran her without the air cleaner and it did not make a difference.
My Echo blower would do the same. A new air filter fixed it.
I ran her without the air cleaner and it did not make a difference.
My CS340 McCulloch chainsaw does this with incorrect or missing air filter:
Starts ok when cold,
Surges badly when WOT after 30 seconds and then stalls.
A new air filter solved the problem
Starts ok when cold,
Surges badly when WOT after 30 seconds and then stalls.
A new air filter solved the problem
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Originally Posted by vw7674
The diaphragm can take a set & get brittle, less fuel delivered, no consistent high speed operation.
There are two diaphragms, one that moves the fuel, another that acts on the inlet needle & seat that fills the fuel chamber. They can both 'take a set' & cause hunting.
A kit with fresh diaphragms may solve it, if there isn't dirt causing the inlet needle from closing.
I agree.
The diaphragm can take a set & get brittle, less fuel delivered, no consistent high speed operation.
There are two diaphragms, one that moves the fuel, another that acts on the inlet needle & seat that fills the fuel chamber. They can both 'take a set' & cause hunting.
A kit with fresh diaphragms may solve it, if there isn't dirt causing the inlet needle from closing.
I agree.
I took her apart again this morning with a fresh attitude and better light. I discovered the primer bulb is cracked. Do you think this could cause the high speed surge, similar to what you would get with a broken impulse line on a chainsaw?
Re the air filter, engine runs the same with and without filter installed. Doesn't that rule out the air cleaner?
All of the circuits are clean and open. Assuming it is not ignition related, it must be either the cracked primer bulb or hardened gaskets. Thx for your help.
Re the air filter, engine runs the same with and without filter installed. Doesn't that rule out the air cleaner?
All of the circuits are clean and open. Assuming it is not ignition related, it must be either the cracked primer bulb or hardened gaskets. Thx for your help.
Assuming the fuel is clean and fresh, I check the air filter, primer bulb, and spark plug, and replace if needed. If they check out, I clean the carb and adjust it if needed. If that doesn't work I rebuild the carb or replace it.
I generally start to treat a surging engine with a seafoam or techron soak, and then running it for a while with fresh gas. However, given the cost of Seafoam vs a new tune up kit, I would just replace everything and call it a day. Especially since the bulb is cracked.
https://www.ebay.com/itm/Carburetor...4839104?_trksid=p2385738.m4383.l4275.c10
https://www.ebay.com/itm/Carburetor...4839104?_trksid=p2385738.m4383.l4275.c10
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Originally Posted by RyanY
I generally start to treat a surging engine with a seafoam or techron soak, and then running it for a while with fresh gas. However, given the cost of Seafoam vs a new tune up kit, I would just replace everything and call it a day. Especially since the bulb is cracked.
https://www.ebay.com/itm/Carburetor...4839104?_trksid=p2385738.m4383.l4275.c10
Don't see any reason to replace everything just because the bulb is cracked. Also, getting a new carb, plug, fuel line, etc for less than $15 tells me quality must be super low. Thx for the link but I would not trust this source.
I generally start to treat a surging engine with a seafoam or techron soak, and then running it for a while with fresh gas. However, given the cost of Seafoam vs a new tune up kit, I would just replace everything and call it a day. Especially since the bulb is cracked.
https://www.ebay.com/itm/Carburetor...4839104?_trksid=p2385738.m4383.l4275.c10
Don't see any reason to replace everything just because the bulb is cracked. Also, getting a new carb, plug, fuel line, etc for less than $15 tells me quality must be super low. Thx for the link but I would not trust this source.
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Originally Posted by artbuc
Don't see any reason to replace everything just because the bulb is cracked. Also, getting a new carb, plug, fuel line, etc for less than $15 tells me quality must be super low. Thx for the link but I would not trust this source.
It's true that the linked kit is aftermarket, and I am certainly in favor of OEM whenever practical/economical. However, at this point i am not convinced that the OEM carbs are superior to aftermarket. In fact, the one i have on my old edger has the same markings as the original. I dont know if it was made as a true replica or what, but it works well. So far I have been running aftermarket carb kits on several pieces of equipment for 6+ years with no problems; originals lasted around 10-15 so too early to tell whether the cheapies will last that long. If they dont last, i will be quick to change my opinion on aftermarket vs oem!
Don't see any reason to replace everything just because the bulb is cracked. Also, getting a new carb, plug, fuel line, etc for less than $15 tells me quality must be super low. Thx for the link but I would not trust this source.
It's true that the linked kit is aftermarket, and I am certainly in favor of OEM whenever practical/economical. However, at this point i am not convinced that the OEM carbs are superior to aftermarket. In fact, the one i have on my old edger has the same markings as the original. I dont know if it was made as a true replica or what, but it works well. So far I have been running aftermarket carb kits on several pieces of equipment for 6+ years with no problems; originals lasted around 10-15 so too early to tell whether the cheapies will last that long. If they dont last, i will be quick to change my opinion on aftermarket vs oem!
Ryan, I just found this which supports your recommendation and experience:
https://handymanwire.com/ubbthreads/ubbthreads.php/topics/951541/chinese-clone-carbs#Post951541
https://handymanwire.com/ubbthreads/ubbthreads.php/topics/951541/chinese-clone-carbs#Post951541
Originally Posted by artbuc
Ryan, I just found this which supports your recommendation and experience:
https://handymanwire.com/ubbthreads/ubbthreads.php/topics/951541/chinese-clone-carbs#Post951541
Thanks for sending that! After these last few posts I questioned whether I am setting myself up for unnecessary maintenance with the budget products! It is reassuring that my success with the cheapies is not uncommon.
I should have mentioned that I am a homeowner and it isn't the end of the world if my OPE fails for a day or two before I have time to repair. If my job depended on it, I would probably take a different approach.
One more thing regarding the fuel lines, etc. IME the little transparent fuel lines and bulb have always failed or were brittle at the time I replaced the carb. By replacing these items along with the carb, I think I am preventing another hour of work in the near future when they actually fail. After all, they have to be removed to replace the carb, anyway.
Ryan, I just found this which supports your recommendation and experience:
https://handymanwire.com/ubbthreads/ubbthreads.php/topics/951541/chinese-clone-carbs#Post951541
Thanks for sending that! After these last few posts I questioned whether I am setting myself up for unnecessary maintenance with the budget products! It is reassuring that my success with the cheapies is not uncommon.
I should have mentioned that I am a homeowner and it isn't the end of the world if my OPE fails for a day or two before I have time to repair. If my job depended on it, I would probably take a different approach.
One more thing regarding the fuel lines, etc. IME the little transparent fuel lines and bulb have always failed or were brittle at the time I replaced the carb. By replacing these items along with the carb, I think I am preventing another hour of work in the near future when they actually fail. After all, they have to be removed to replace the carb, anyway.
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The high speed circuit in the carb is plugged, probably with varnish caused by old gas. Adding something (like Seafoam) to the gas won't help, the restriction will have to be manually/physically removed. The carb does not need to be replaced. I have gone into detail about how to do this in the past, so I won't go into it again.
wag123's suggestion is certainly worth exploring.
However, i just remembered an issue my brother experienced a few years ago. His trimmer gets a lot of use (on his farm) and had some bogging and poor performance at wide open throttle. Seafoam and carb adjustments did not help. He then removed the fuel filter and left it off to test it's functionality. The trimmer ran fine with no filter...installed a new line/filter and all was well.
However, i just remembered an issue my brother experienced a few years ago. His trimmer gets a lot of use (on his farm) and had some bogging and poor performance at wide open throttle. Seafoam and carb adjustments did not help. He then removed the fuel filter and left it off to test it's functionality. The trimmer ran fine with no filter...installed a new line/filter and all was well.
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