Walbro WT 424B Off Echo ST

Hello to all, Cheese & V8! I was given an Echo ST recently. While it looks in great shape unfortunately it was seized. Recently I found an even older echo at the junk yard. Can't find a Model number but it is the typical looking Echo ST and is almost identical to the newer version I have. It was manufactured sometime between 1995 & 1999? As you can imagine it was in a sad, rusted & extreamly 'oil and dirt' encrusted condiction. In all outward respects it was totally shot! Well, to my welcome surprise the head, piston and rings are in perfect condition and can be used to repair the newer ST. The WT 424B carburator was so covered in grime it was difficult to see it's features. The carb, after I cleaned it, was as if it were brand new. The plates were so bright they looked like gold. HERE IS MY QUESTIONS: Does this carburator really sell for over $80.00 and if so...Why is it so expensive? I don't have access to a good reference book but the Walbro site shows a WT 424-1. Couldn't find a 'B'. Can you explain what the A's, B's Ect. mean and is WT 424-1 the same as WT 424B? I assume some minor differences? LAST 2 QUESTIONS: Would you advise not trying to remove the low and high needles? If you think I should while rebuilding it how do I remove the 2 small red (CA. required) adjuster covers to get to the needles? The area for the needles is a raised part of the extrusion and seems to be completely encapsulated in metal! The only thing visable is the top of the 2 red plastic needle covers? As always thanks for everyone's help, Ron

 

So both carbs were the same? Usually a flat head screw driver or needle noses work to take the little limiter caps off, if you have two, worst case scenario is you mess one up. IF the needles are metal, I would advise removing em, trash and gummy gas won't get flushed out of there well or at all if you don't. I'm not sure on walbro's carb numbering though, but it could have been replaced by the WT 424-1. Though you'll have it easy with the walbro, they are great to work on.

 

V8, these limiter caps are flush with the surface of the carb body? I'm sure there is a trick to this but I've never run into plastic caps FLUSH with the surface. I've mauled a hundred of the plastic tips with the metal caps over the stand out valves with ease but there isn't any obvious way to attack these? Thx, Ron

 

Hi Ron!

I'm not sure about the model # coding for walbro carbs either. I haven't got a book for them. I can't even say that I've seen what you're describing. Could you maybe screw a small wood screw into the plastic caps to get a hold of them, and pull the screw and in effect, pull the cap out of the recess? I would try to remove them if at all possible without ruining the screws. If you think the screws might get ruined, try the rebuild without removing them first.

Some of these 2 stroke carbs are pretty expensive, even though they are almost the same as the cheaper carbs. I suppose it is because it is not as common of a carb #. They probably don't sell near the volume of those carbs as they do weedeater featherlite carbs. I paid about $60 for a walbro for a stihl recently. It was very similar to most of the common walbros, but still different. Different, even, from the other stihl carbs I had on hand. There are so many darn subtle differences in these little carbs.

 

Leave it to me to run into the unique, unusual and, of course, most expensive...what luck! I really appreciate your help and that of V8. Your explaination of the probable reason for the "High" price for this carb makes good sence! Thanks again, Ron

 

You're right about the price most likely...low production. The "B" is more for the factory's than for the consumer's/technician's reference. The reason for the recessed limiter cap area is to prevent the average consumer from tampering with them. Thank the government for this...EPA emissions standards. You'll see that once you do remove the caps that it will be near impossible to now adjust them...near, I say. Think smart, not hard. I've modified an old splined ID, limiter cap to use by removing (grinding) the OD of such so that you can insert it into the relatively small, recessed area and pressing them on the adjusting screws. The old caps have a screwdriver slot and the needles are now adjustable. It is much easier to accomplish this task if the carburetor is off the unit and BTW the carburetor rebuild kit is part number K24-WAT.

 

Puey61...great tip. Cheese had suggested a similar if not the same method over a year ago. I haven't made it yet. Sounds really simple but "Why do today what you can put off untill tomorrow". Ha! Well I need it now because $82 plus tax & shipping "Just Ain't Gonna Happen" this one will have to get fixed..

I have a question specifically for you Puey61, maybe others will have suggestions as well. I have started sniffing around some other forums with "Go Karts" and "Racing lawn mowers" as the topics. I have seen your name and advice on one, both and possibly more forums but don't remember specifically which ones? IF YOU DO HAVE THIS INFORMATION I will appreciate it and promise to go over to the other forums for this type question in the future: I want to learn how to build a really nice go kart with springs, big tires and HaOOga horns, a CB antenna with a flag on it and two seats. One for me and one for the Grandbaby. All kidding aside, speed is not a factor but a comfortable ride is! The biggest bumps I'll be taking are the kind you find on a well graded county road. I have Briggs 5 HP's up to Honda 250 3 wheeler engine with transmission, chain drive, disc brakes, etc.??? I have to start simple so here, finally, is my question: Can you direct me to one or more sites, or books, or companies where I can obtain a working knowledge of karting terms and diagrams of fairly simple mid level type karts? I can find everything "I Think" I need here and there but don't have a very good point of reference? Thanks in advance if you or anyone else can provide this hapless old man some direction.!

Finally thanks for all the help with the 2 cycle and it's 'Expensive carb...Ron