Can Carb be Adjusted on Honda Trimmer?

[CacaoBoy]

I have a Honda string trimmer, model HHT35SUKAT. It will start and idle, but dies when accelerated. Most likely there is a partial clog. Considering the modest cost of a new carburator, perhaps the most efficient fix will be to replace the carburator rather than cleaning and rebuilding, but before doing that I wanted to try to adjust the carburator if possible. There is nothing obvious on the carburator to adjust, the owner's manual says nothing about adjusting, and I can find nothing online.

Any information or suggestions for adjusting? Thanks.

 

[Conquistador3]

The carburetors used on Honda GX22/31/25/35 engines are all members of the Walbro WYB family, meaning non-adjustable apart from idle.
Early members of the WYB family had a nasty tendency to wear out the carburetor needle seat very quickly, meaning the needle would get stuck during operations. Worn seat = new carburetor needed.

Let's just say Walbro WT's and WYB's are very hit and miss when it comes to rebuilds, but kits are so cheap nowadays a rebuild is always worth a shot.

 

[CacaoBoy]

Thanks. That's what I figured. I see replacement Chinese carbs can be bought for about $13 and a new OEM can be had for $26, so it is hard to justify even a few dollars for a rebuild kit. And based on past experience with non-OEM carbs I would avoid the $13 ones.

 

[Conquistador3]

$26 for genuine Walbro? Why haven't jumped on it yet? They are so expensive here in Europe...

If yours has anything over 50 hours on it I suggest checking the valve cover gasket hasn't started leaking yet. Very common issue on those small Honda's as hours pile up, but apart from tear and wear that's about it. My uncle's UMK431 turned 20 this year and, honestly, it's lkely to last another twenty years if wear items such as fuel tap gaskets and carburetor kits remain available. Those small Honda engines can only be killed by running them without oil or air filter.

 

[CacaoBoy]

Thanks. There has been no sign of leakage from the valve cover gasket, but I will double check. I also recieved a suggestion to to check the valve adjustment and will give that a try before ordering the carburator. And, yeah, $26 from Shanks.