Echo hedge trimmer

[KE4AVB]

If IRCC the one with the double is the pickup and other is the return.

[bgsengine]

Zama RB carburetor, return line is typically the nipple closest to the air cleaner

[38racing]

Zama RB carburetor, return line is typically the nipple closest to the air cleaner

that's what I'm seeing. so he had the hoses reversed but like I said both hoses were in fuel so maybe that's why it idled. I'm going put pump together correctly along with hoses and see if it runs.

[38racing]

So I am putting it back together and I find that the carb intake spacer was rotated 180 but not the gasket to the block. The gasket to carb to spacer was also rotated 180. I reassembled as per partstree.com ipl picture. So with rotating spacer, proper placement of pump stuff and fuel pickup on correct nipple and metering lever height looked ok at even with gasket surface I was confident that it might run. Well no change. So I decided to put the carb in the ultrasonic cleaner. I did however leave the main jet in place. So after that I put it back together and no change. Idles but on throttle up it runs rough and not up to rpm. As I held it running full throttle I slowly added choke and indeed it reached a point where it came up to normal speed and smoothness so I am concluding that I still have a fuel delivery problem. I guess that I have nothing to lose by pulling the main jet now . I guess the other possibility is an air leak but gaskets seem ok and stuff is tight. It was mentioned about it being adjustable but still haven't found that in the zama manual.

[38racing]

he talks about adjusting the jet with a screwdriver but he doesn't actually show what he supposedly does to make it run.
https://www.youtube.com/watch?v=wTL6CMlDbeM
Ok, think I found what I need in this video
https://www.youtube.com/watch?v=RvRR0Vv_iHQ

[KE4AVB]

The plug ID is slight less 2.5mm so anything that is threaded 2.5mm will go into a couple threads so you can pull the plug. Yes Echo tool is left hand threaded. The plug itself is not threaded but does have ID threads afterwards and it doesn't matter if they are left or right hand threads. It is just that Echo chose left hand bottom tap design. Now Echo do have a 3mm tool for removing the damaged plugs where someone tries digging them out.

Now once the plug is remove adjustment the main jet may still not work if the main jet is partially plugged. It has teeny tiny hole in the tip. If it is plugged then the brass plug retainer would need to be removed so you can remove the jet to clean it. I would need to go to the shop to see what size bottom tap you need to do this. Of course this destroys the retainer and a new one will need to be installed. This retainer not only holds the EPA plug but also prevents the main jet from falling out. I have both these on hand along with the replacement EPA plugs.

Removing the plastic plug by other methods can damage the jet head making it necessary to replace the jet. Also in one of the videos the guy talks about grinding a screwdriver so it straight sided. Why when all you got to do is go to Dollar General, Walmart or other store (even Grocery stores have them) and pick up cheap set micro screwdrivers besides you will get some of the other sizes along the 0 and 00 cross points if you work on small stuff enough. These flat tips are hollowed ground and will help prevent climb out which damage soft brass jets.

This is what the main jet looks like:
PN 0030252 Replaces 0030203

[38racing]

so a machine tap of 2.5 to 3 mm at it's tip should likely work to expose the jet? this retainer you speak of, is it under black plug that's exposed when metering cover is removed? I recall the first guy talking about it. Or is that something different all together. the zama TechGuide_2007.pdf shows a different plug setup and an o-ring

[KE4AVB]

No it is between fuel supply and return line in the cube at the primer assembly. The black plastic EPA plug is held in by this retainer. Both of my 4mm tap has brass filings on them so I have both removing these retainers. The plastic piece you're referring is actually held in by the main mixture screw which is 90 degrees from it. This is why heated objects can damage this part which has a hole the center under the bottom side that leads to side holes in the main mixture screw. This plastic part is not available separately from the whole carburetor. Plus you do not want to try removing it where the main mixture goes thru it has spread making nearly possible to remove plus you can it easily if you try.

Image of retainer - Zama 0009083


What are seeing in the tech guide is the non-adjustable metering nozzle ie jet as note you don't run a wire or other item thru as has a check valve in it.

[bgsengine]

No it is between fuel supply and return line in the cube at the primer assembly. The black plastic EPA plug is held in by this retainer. Both of my 4mm tap has brass filings on them so I have both removing these retainers. The plastic piece you're referring is actually held in by the main mixture screw which is 90 degrees from it. This is why heated objects can damage this part which has a hole the center under the bottom side that leads to side holes in the main mixture screw. This plastic part is not available separately from the whole carburetor. Plus you do not want to try removing it where the main mixture goes thru it has spread making nearly possible to remove plus you can it easily if you try.

Image of retainer - Zama 0009083


What are seeing in the tech guide is the non-adjustable metering nozzle ie jet as note you don't run a wire or other item thru as has a check valve in it.

On Echo those are adjustable if you remove the tiny (4mm) black plug from the center of the retainer , then you can see the slotted screw behind it , need a very small (I.E. Precision screwdriver) to fit through the hole of the brass retainer and thread out the high speed adjustment screw to pop the retainer out and remove the adjustment needle

The low speed adjustment is covered by a similar 4mm black limiter plug and the adjustment screw is down the center of the rotary valve and requires a special adjustment tool to adjust that. You do NOT want to go in blind on adjusting those though ,as the procedure for correct adjustment varies between models (and serial numbers of the same model) both for the initial setting and the adjustment procedure. (which is why they want it done only at an Echo dealer) with model and serial I can get the exact (and correct) carb adjustment bulletin for them with all those details.

[KE4AVB]

I just didn't want risk stripping those threads beside by the time I see these most times some shadetree has already damage the retainer. They only cost me 64 cents each. I can barely find a cheap soft drink for a cup coffee for that anymore.