Compression on ECHO Weed eater

Reply

  #1  
Old 10-01-09, 07:11 AM
Member
Thread Starter
Join Date: Oct 2009
Location: Hampton VA
Posts: 35
Cool Compression on ECHO Weed eater

Hello everyone,

I am new here. So this maybe a topic already covered once.

First thing I need to know, What is a good Compression pressure for ECHO or even any product out of the same size and design? 100, 110, 125, 150 What is good and or bad?

I am asking this becasue I have an ECHO SRM 260S and can't seem to keep it running and make it idle at all.

I took off the Spark arrester and it runs but short term. I cleaned it and placed it back on and will not start or starts short period with allot of effort invovled.

But with it off it starts hard and I can get it to run hard and fast.

The Carb is a Walbro WYJ 250A. I down loaded the book. I followed it to the T.

So here what I have done so far as in trouble shooting and or repeairs.

1. Checked Spark, There
2. Checked Compression, PSI is 125
3. New Gas lines.
4. New Primmer Bulb
5. Cleaned the Carb, I have not rebuilt it yet, Next step.
6. Adjsut the Needle and is set right.
7. Adjusted the IDLE needle in side the slide assembly 10 to 12 turns in and even backed it out. Hit or miss when I do this. I have a question on the idle fine tune screw on the top that pushes on the throtle arm. How should that be set? All the way back and then set the internal idle screw? Unknown here and can not find any data on that.
8. Cleaned the Spark arrester and muffler assembly.
9. Cleaned and set the gap on the plug.

Could be the Diaphram is to stiff, small hole if so then I will rebuild it!

I am at a lost other than completley replacing and or rebuilding the carb from ground zero.

Any recommendations be great. I have tried everything excpet agian total rebuild!

Thanks Henry
 
Sponsored Links
  #2  
Old 10-01-09, 07:59 AM
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,728
The problem isn't the compression, it's probably in the fuel system. 125psi is workable.

First check for spark when it dies - ground a good plug and turn it over - you need a bright blue spark. ** Cleaning the plug on a two stroke is pointless - replace it.

Then the fuel cap - loosen when it acts up up to see if it makes a difference.

Put a new filter in it and check the fuel lines to make sure they are pliable and not pin holed.

The problem is likely in the carburetor/fuel pump. The latter would be the diaphragm you mentioned as being stiff and pinholed. It should have a kit put in it.

The idle mixture screw (low speed) is typically set at 1 1/2 turns out from lightly seated as a starting point for tuning. Then adjust it for good acceleration.

The screw you have for holding the throttle open is the idle speed adjustment. On a weed eater, turn it down until the engine is about to stall, then back up until you have a smooth idle. Don't worry about a spec on it.
 

Last edited by marbobj; 10-01-09 at 08:40 AM.
  #3  
Old 10-01-09, 08:28 AM
Member
Thread Starter
Join Date: Oct 2009
Location: Hampton VA
Posts: 35
Smile Thank you

I thought I was going in the right direction on this.

i talked to the ECHOMechanic and he said the spec formt he Maker is no less than 85 PSI and no higher than 145. i found different blogs and they said 110 is what he likes to see at the lowest point.

I am going to replace all the gas lines and Gromment and rebuild the Carb.

I will then update everyone on what I found as the smoking gun.

Thank you for your input guys!

Henry
 
  #4  
Old 10-01-09, 06:20 PM
Member
Join Date: Feb 2008
Location: usa
Posts: 755
Compression of 125 PSI is excellent, maybe a little high. The 260 service manual gives compression as 115 PSI (standard). It then gives percentages of 80% for low limit and 130% for high limit. In short, compression is not a concern.

Carbon buildup sometimes increases compression. I suggest you remove the carburetor look closely at the engine exhaust port for carbon buildup. Also check inside the muffler for carbon buildup.
 
  #5  
Old 10-02-09, 03:51 AM
Member
Thread Starter
Join Date: Oct 2009
Location: Hampton VA
Posts: 35
Wink Thanks

Ok,

I do have carbon build up in the muffler and in the intake area.

So I will remove that and rebuild the Carb and replace the gas line and Groments.

I appreciate the help.

Just puzzling why it wont run and stay running. I have fixed allot fo these and never exprienced this before.

Thank you!

Henry
 
  #6  
Old 10-02-09, 06:49 AM
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,728
Once you have determined you have good spark while it's acting up, short term running is quite often attributed to fuel flow.

That normally comes down to vented gas cap, fuel filter, fuel pump diaphragm.

A hard restart can go either way = flooding by a leaking needle valve/gaskets or no fuel.

On an older two stroke engine you should always think about vacuum leaks at any mating surfaces and especially the crank seals.
 
  #7  
Old 10-22-09, 04:08 AM
Member
Thread Starter
Join Date: Oct 2009
Location: Hampton VA
Posts: 35
Cool Leaking gas

Hello everyone,

I need help. I have a ryobi weed eater and I totaly rebuilt the Carb on it. it then runs fine and does good work.

But as it sits and or gets hot all of a sudden gas starts leaking out of the Carb. Then it will not start again.

What is casuing this to happen. it is the second carb to do this on this machine.

Please someone with exprience give me an answer to the issue.

Thank you!

Henry
 
  #8  
Old 10-22-09, 04:19 AM
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,728
You should probably put this in a new thread. But regarding your problem, when you've run the engine and about to sit it down, loosen the gas cap and see if it still leaks gas. The relief vent on the cap may be plugged = new cap to fix.
 
  #9  
Old 10-22-09, 04:33 AM
Member
Thread Starter
Join Date: Oct 2009
Location: Hampton VA
Posts: 35
Cool Thanks

Thank you so very much. That is what we thought.

Now back to my ECHO issue I can get this SRM 260S to run. I still think the Carb that was on it was wrong size.

I placed the ryobi carb on it which was smaller and it ran rought but ran.

I have done everything to this carb and the weed eater and it will not run and stay running. The Maker of the Carb says to use a different model carb than listed in the manual. So now i do not know what to use.

The Book says a WYJ 250A and the maker says to use a WYk-70-1. The WYJ has a 12.2 M vneturi as the WYK has a 10.0M Vneturi.

So again what is the right answer?

Henry
 
  #10  
Old 10-23-09, 04:01 AM
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,728
Use what Echo says to use.
 
  #11  
Old 10-23-09, 05:00 AM
Member
Thread Starter
Join Date: Oct 2009
Location: Hampton VA
Posts: 35
Hello

Thanks for the help,

Another Question., On a Tecumesh engine and or any engine the idling arm that connects to the Carb and when the engine is running maitians a constant speed and moves back and forth is that connect to anything or does it rest agaisnt a fly weel type assembly.

Reason i am asking a customer took it off and it was laying back away from the engine adh tried starting it disconnected. Normal it has tension on it and is pulled forward with it connected to the engine. but it was laying down disconnect and he tried starting the engine. SO I didn't know if it would get damge in any way having done that.

thank you and have a good weekend!

Henry
 
  #12  
Old 10-23-09, 06:57 AM
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,728
If we're on the same page, that would be the governor arm. It is moved by an assembly that includes flyweights, etc. It depends on the engine as far as parts and configuration.

The throttle moves the governor and the governor controls the carburetor.
 
  #13  
Old 11-02-09, 07:00 AM
Member
Thread Starter
Join Date: Oct 2009
Location: Hampton VA
Posts: 35
Question Weed Eater issues

Ok I have been trouble shooting this darn ECHO SRM 260S. I have done everything and even bought a new CARB the dealer recommends.

Now it want's to start but wont keep going.

So then I removed the exhaust and tried again starts a little and stales out.

Then I said let me adjust and wire brush the Coil and it started and ran a little better and even ran a little longer.

So my quesiton is the coil bad. I thought coils either worked and or they just didn't do anything?

Can the coil acutally be very weak and not be providing enough power to the spark plug?

Inside help be good if you can guys!

Henry out!
 
  #14  
Old 11-03-09, 07:36 PM
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,728
A coil can get progressively worse and along that line of thinking, if it's nearing the threshold of totally dead, what you have could attributed to the coil.

However, that sort of thing you're describing is usually fuel/air mixture.

That can cover some cover some ground, though = carb, fuel lines, fuel pump (in carb), fuel tank, filter, cap, vacuum leaks at mating surfaces, and lastly the crank seals.

Before you do anything make sure you have the easy stuff done = good fuel, air filter, spark plug.
 
  #15  
Old 11-04-09, 03:25 AM
Member
Thread Starter
Join Date: Oct 2009
Location: Hampton VA
Posts: 35
Thumbs up Hi

I found it, I took the whole thing down to bare min and made a plate and placed 3 pounds of pressure on the engine and then placed it in a bucket of water and found the main oil seals front and back leaking badly.

I did the easy stuff already and could not understand why I was having such a darn issue. I never ever had to go in this area of repair before. But I did get it.

Thank you for all the advice and help on this porject. I have learned a ton more about these little engines.

Now I can better assist others as well.

Thanks MAR!!!!

Henry
 
  #16  
Old 12-14-09, 01:35 PM
Member
Join Date: Jul 2004
Location: New York
Posts: 239
Echo weed eater

Hello this question is because i am having the same problem with my echo but i dont understand how you found the air leak>> Could you explain this just a little better so i can try the same thing? Thanks for any help..
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes