This might seem like a silly question but have you also done the routine service to it? Like cleaning the air filter, changing the fuel filter, spark plug, check the oil, etc? Does it have a low oil saftey shutoff? If you've done this it might be worth it to take it to your local Honda power equipment store for service. You never know, they may be able to show you something simple you overlooked.

And yes, water flowing through the pump helps remove heat. Never run a pump dry too long because you can ruin the seals.

jmancan, funny you should ask. I had this problem last year with both pumps running badly, so I took 'em back to the dealer from whom I had purchased them. They replaced the air filters, the fuel filters, spark plugs, and changed the oil in both (to the tune of $100...I coulda done all that, but what the heck). They said the pumps worked fine, and I was all excited that now I had two good functioning pumps; one for each well to use during last summer's drought. Well, guess what? One of 'em seemed to work OK (this is the one I'm now having problems with) and the other???well....one 95+ degree afternoon after working my butt off all day and sweating an hour trying to get the thing to work for more than 5 minutes (varying the throttle speeds, the choke, etc., etc.) I got so p***ed off, I threw it on the stone deck....so, now I use it for parts. So, now I'm down to one pump, and I need it to keep my newly planted grass seeds moist...and, guess what???? So, I'm not too happy with Honda. Is it possible that using 89 octane gas is having a negative effect? I'm reasonably sure it's a carb problem, but how do I fix it?
Many thanks, again.

Are you using gas that is more than 6 weeks old. If so, dump it and get fresh. Also when stripping the carb, remove the brass main jet and the tube behind it and carefully clean the small bleed holes. An inexpensive welding tip cleaner works well but be gentle.

canguy, yep, the gas is fresh. I worked on it somewhat today. The carb is one of those tiny Walbro ones, and the orifices are miniscule. I attempted to clean all passages, orifices, etc., and it would only fire up and run for about one second. So, I will try again tomorrow. Oh, I removed the fuel filter just to be sure I was getting a good gas flow, and I cleaned the spark arrestor, and replaced the plug.

Finally, with time running out, I just decided to replace the carb with the one from the donor machine. Now, it runs like a champ. So, I guess I will need to rebuild the original carb at some point...does Walbro make rebuild kits for these carbs? Anyone know?

Just in case somebody is still looking for one of these, here's one source -- $8.95

Here is a link that might be useful: Walbro carb rebuild kits

Even if no dirt, old fuel or other user unfriendly maintenance has occured, 2 stroke diaphragm carbs should be refreshed at least every other year. The diaphragms get stiff and don't work right. As you found, a inexpensive kit will go a long way to prevent unwanted problems.

I have a Honda WX10 pump also. It started running rough after setting up for 6 months. I only use it to pump pond water for my fruit trees during a drought, so it does not have a lot of total hours, although when I do run it, it is 2 days all day. After running a couple of tanks of fresh gas and a lot of swearing it is running much better. Your first post was unclear about your WX10 being 4 stroke or 2 stroke, but my WX10 is 4 stroke and does not use oil in the fuel. If you are using oil in a 4 stroke that would be a problem. The water in the pump only cools the pump. The engine is air cooled. I don't believe this engine has a low oil shut-off.

Bluestoneclay,

Many thanks for the help comment. I've been struggling with the WX10 for the last year and was totally frustrated. I had just placed it on the work bench in the garage so I wouldn't forget to take it to the dealer Monday morning for an expensive and most likely, non productive visit. I decided to google search WX10 pump problems and found your post. I have been experiencing the exact same symptoms that you described. I carefully took the gas cap apart and removed the small rubber air vent. This morning I filled the little WX10 with gas and took it down to the creek to give it one more chance. It fired right up as usual, and then I ran the throttle up to wide open and waited for it to stop running, as usual. To my surprise it ran perfectly, wide open throttle, without even a hesitation for a solid hour. Your post saved me an expensive trip to the dealer and now I have a dependable pump that I can count on to do the job every time I need it.

Many Thanks Again !!!

RK

Bluestoneclay and trapandclay,

I am so glad I found this! I have struggled for a couple years with my WX10. It dies after several minutes of running. I have my pump at a cabin we have in Canada. Next time I'm up there I will look for this cap vent. I use the pump to prime the water system for our place. Never thought of the cap vent possibly being plugged! Thanks! I will let you know later this summer how it went.

I have had these exact problems with my WX10, pump wont run on full throttle for more than a few seconds and dies on 75 % throttle after about 5 minutes, it has been very frustrating. Thanks for your advice trapand clay! I will try looking st thd fuel csp vent.

You were 100% correct bluestoneclay and Trapandclay. I went and cleared out the valve that sits inside the fuel tank cap and my pump now runs fine. Previously it would die after a few seconds on full throttle and ran on partial throttle but then could die perhaps 5-10 minutes later. I think it had a partial air blockage to the fuel tank. THerefore when the pump used more fuel the fuel tank would have gone into a vacuum and starved the engine of fuel. This is why I would walk up the hill when I did my irrigation and noticed the pump struggling when it had more head and was labouring. Once I knew what it could be I cleared out the little valve device under the fuel cap and the pump has run for 1 hour full throttle with zero issues. Thanks Heaps!! you have saved me lots of frustration and no doubt costly service costs at the agents!

Could someone please show more detail using a photo of what was removed and how you removed the rubber piece found within the gas cap?

I am having althe same issue and would like to resolve it!

Thanks!