Honda GCV160 Engine wont run when choke is off?

[DPDISXR4Ti]

Thanks for the feedback - you were both correct!

The main jet was clogged - couldn't even see through it once I got it out, which was not too easy to do. Initially it unscrews easily from the bottom of the carb (after removing the bowl), but then it just spins. You need to have a very light touch with the screwdriver after unscrewing for a bit, then the jet drops down a bit before catching another set of threads to finish unscrewing all the way out.

All of my carb cleaning tools were too big, so I just used a needle to clean out the orifice in the jet. Then it was easy to screw back in and reassemble everything. In hindsight, the jet didn't need to come all the way out - I could have cleaned it in place - I'll know better next time.

I'll paste below the comments I found on another forum, just to have another's perspective....

rotti1968 wrote...
certified Honda mechanic here, your main jet is clogged along with one or all three of the transition holes in the venturi . remove the carburetor, remove the bowl and down the center of the carb is your main jet unscrew that being careful not to damage it, clean with what works the best is a welding tip cleaner . then looking into the throat of the carb on the throttle side you will see three small holes, one or all three may or are clogged you can also use the tip cleaner here but be very careful not to break it off in one of the holes, then soak in carb cleaner. if after all of this you put it back together and it still runs only on choke put a new carb on it....

 

[bertsmobile1]

Did you pull the emulson tube out as well and clean all of the holes in it ?
The emulson tube is the bit that pokes out into the carb throat ( venturi to be specific & sound nerdy )
Once the main jet is out it pushes down and comes out the same hole.
If the main jet is gummed up then the bottom holes of the emulsion tube will be gummed up as well.

 

[Boudreaux In Eunice La.]

Thanks for the reply on the clogged jet ................

Is It running like it should be running ???

Bert told you in POST number 10 to take the MAIN jet out and THEN pop the nozzle out of the emulsion tube by pushing it down with a screwdriver or something else.....

I do know people that just pop the jet out and just spray carb cleaner up in there and it works fine.......

Sometimes that works and a lot of the times it doesn't ................ Those nozzles are really clogged up most of the time....

Please stay away from etho gas Mon Ami.............

Let us know ~!~!

 

[DPDISXR4Ti]

Did you pull the emulson tube out as well and clean all of the holes in it ?
The emulson tube is the bit that pokes out into the carb throat ( venturi to be specific & sound nerdy )
Once the main jet is out it pushes down and comes out the same hole.
If the main jet is gummed up then the bottom holes of the emulsion tube will be gummed up as well.

I did not remove the emulsion tube. I was able to push it down after unscrewing the jet. In hindsight now, I thought at the time that it simply was the upper part of the jet.

But the engine is running fine now - starts up fully choked and then I gradually open it up all the way. I ran a tank of fuel through it late yesterday, splitting some firewood before sunset (far less than planned due to playing small engine detective).

If I have any recurring issues in the future I'll remove and clean both the jet and the emulsion tube.

 

[RonPa]

unfortunately most people are fairly sefish.
They come here with a problem an when they get it solved vanish with not so much as a thank you.

do a lot of these engines fited to fire pumps provided to volunteers with very little training.
They are placed in an enclosed trailer at the end of streets where bushfires break through.
So they sit in a small enclosed steel space all through summer oft with the fuel taps left on.

You will need to unscrew the main jet which is inside the brass tube,
You will also need to push the tube out, from the carb throat into the float chamber and clean out all of the cross drillings.

There are times I have to give the carbs well over 2 hours of ultrasonic cleaning to get them to flow properly as modern fuels leave a tar residue that is very hard to remove.
You should also take the tap apart and clean it and the sediment trap below it out.
There is also a filter in the end of the fuel outlet in the tank that gets clogged so it might need to be removed as well.

Problem solved.
Thanks for the encouragement here. My Honda 160 GCV is on a low-end Homelite 2700 PSI pressure washer. Same prob as others had: it idled OK but under load, would starve- if I used the choke it sorta ran OK.
I took the carb apart and put it in a can of carb cleaner. I ran a tiny wire thru the main jet and it now runs under load just fine. I suspect the main jet was the culprit, as I couldn't see a clear orifice when it was held up to light.

One challenge I had was to figure our the order and placement of the several gaskets. I suspect the sequence was not critical, and in the end, it ran fine.

Thanks all,

Ron
Calif

 

[Boudreaux In Eunice La.]

Thank you Ron for letting us on this forum know that it helped you ...........

 

[silverseal99]

Same issue as post #15 with a Honda 160 GCV powered pressure washer in the Democratic People's Republic of California (read: gasahol)--after many years it succumed to the Commisar's mandate and would no longer pull full power without full choke. Removing the carb, partially disassembling, flushing with various solvents and ultrasonic cleaning didn't work. I needed to pull the main jet and emulsion tube and ream the attendant orifices to get it to run properly. Some of the gaskets self-destructed on disassembly so I recommend you have a set on hand.

What I learned:
1. Chemically flushing or ultrasonically cleaning the carb without pulling the main jet and emulsion tube may work but were insufficient to resolve my issue--I had to remove and ream key passages in both parts.
2. The main jet comes out in two stages per post #11: stage 1 is to back it out part way with a screwdriver until it "stalls" (comes no further). A toothpick lightly inserted into the main jet orifice provided sufficient manipulation and torque to get the jet started in the outer set of threads. Once started, complete removal with a screwdriver was quickly accomplished.
3. The emulsion tube protrudes into the throat of the carb. Once the main jet is removed, a little shove with a flat bladed screwdriver dislodged the emulsion tube but it didn't drop out the main jet channel--it took a little coaxing with the hook end of a machinist's scribe for it to drop clear. Pay attention to its proper orientation.
4. The main jet has a #68 drill size orifice. Although the jet appeared optically clean and clear, careful probing with numbered drills revealed that it was choked down to 0.061mm from its specified diameter of 0.068mm--a 20% reduction in area! I hand reamed the main orifice back to 0.068 with numbered drills.
5. The emulsion tube has two sets of orifices: #67 drill for the larger (lower) and #71 drill for the smaller (upper). Although the emulsion tube was optically clear, each orifice was two drill sizes smaller despite prior chemical flushing and brushing. Hand reaming with numbered drill bits restored them to spec.
6. My Harbor Freight set of numbered drills didn't go small enough but a 20 piece #61-#80 set from Amazon did the trick.
7. A set of gaskets from Amazon was a must. The bowl gasket had to be destroyed to remove it. Although the replacement was a different fit and finish, it didn't leak and did the trick.

Bottom Line: Pressure washer now works like a champ--starts on the first pull, pulls power like it used to.