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View Full Version : Zanba RBK75 Carb Rebuild- On Echo Hedge Trimmer


ed2hess
08-03-2011, 05:56 PM
What is the procedure for getting the high needle to back out. Something stops it and I am afraid to force it. There is a brass collar where you stick the screw driver in that probably needs to come out. When you have the carb apart there is a plastic plug above it. The carb is bogging and I know it isn't getting enough gas with the needle full CCW.

I have had the carb apart a couple times and cleaned up all the holes I could find. New kit is next but don't like not being able to clean that high needle chamber. Oh I put a new carb on off another unit and it works fine. I got two doing the same thing.

dutch1
08-03-2011, 08:02 PM
Is there a plastic limiter cap on the needle? If so, you will have to pull off the limiter cap in order to remove the needle.

ed2hess
08-03-2011, 09:36 PM
Is there a plastic limiter cap on the needle? If so, you will have to pull off the limiter cap in order to remove the needle.

No....I will take a picture. There is brass collar that is apparently lightly pressed into casting of the carb. The collar has a hole big enough to get the adjusting scrwdriver thru it. I know that I have to take the collar out but I don't know if I have to take that plastic plug out. The plastic plug is perpendicular to the needle and when I removed it from my scrap carb I can now see the needle screw threads. I don't know if it somehow limits the screw from being backed out all the way or not. I am concerned that if I take that plug out then I will have either a air or fuel leak. The plug didn't just come out I had to drill it out entirely.

sharkey
08-04-2011, 11:16 PM
Can you post a pic of this carb that your working on?

ed2hess
08-05-2011, 07:19 PM
Kinda not very good at close ups...The largest hole is where there was a slug of plastic. I drilled it out. That hole goes down to the needle threads. When the needle is all the way CW there seems to be shank on the needle
that may have hit the plastic. The second bad picture kinda shows the brass collar that is pressed into the alum casting and also keeps the needle from being taken out. I will try better pictures.

MowerMedic77
08-05-2011, 07:47 PM
Just keep backing the screw out, it will push the brass plug out of the carb body.
I put the plug back in using a 4 mm allen screw the raised end of the plug fits into the spot
Of the screw that you would normally put the allen wrench. Then just lightly tap it back into
The carb body so it's flush like when you started.
Posted via Mobile Device

ed2hess
08-05-2011, 09:40 PM
The plug would not pop out I drilled a small hole in it and then got a hook but no luck. I used a drill bit to grind it up....it is now a pile of dust. My question is...why does a plug need to be in that hole? Will the needle come out by just screwing the needle CCW forcing the collar out, leaving the plug in? This is a scrap carb I was just using to study the situation.

dboyd351
08-06-2011, 10:15 AM
Ed,
Take a look at this post and see if it helps any:
http://www.lawnsite.com/showthread.php?p=3839216#post3839216

I can't tell if he is addressing your issues, but he has got some good photos, step by step instructions and advice on using an old drill bit to press out the check valve.

ed2hess
08-07-2011, 12:19 PM
Ed,
Take a look at this post and see if it helps any:
http://www.lawnsite.com/showthread.php?p=3839216#post3839216

I can't tell if he is addressing your issues, but he has got some good photos, step by step instructions and advice on using an old drill bit to press out the check valve.

Thanks I am making progress on the problem. That thread points out that I should have done a leak test on the carb. I don't know how to do that so well take it to dealer.

ed2hess
08-07-2011, 05:06 PM
Well I put a new carb kit in and I backed out that high needle and cleaned that jet hole. Put it back together and the results are the same. The unit bogs and fails to go to high speed. A second unit with same carb and same age ran fine after I got the plastic plugs out on both the high and low jet and adjusted them a small amount. So since I got a new unit with a new carb same model I am going to replace parts one by one until I find out what the problem is. I am coming to the conclusion that I don't think I will buy any more units with that zamba model carb.

ed2hess
08-15-2011, 10:13 PM
Carb finally fixed and hedge trimmer runs like new. The problem was the adjustment of the inlet needle lever. It was wide with old parts and with new parts compared to a new carb. I took it to dealer expert and he agreed. He advised me to strip it down and put it in the carb cleaner device. It is hot water and electricity...will get more info. It cleaned it for 3 hours. Put it back together adjusted the lever to just under flush relative to straight edger across casting. He advise to put a spot of super glue on the black plug just in case it is getting loose. The unit started fine and rev right up. I think I got this model nailed. Got a new little toy from target to look into small places.

dboyd351
08-16-2011, 06:54 AM
Glad you got it fixed!