# Honda hs622 Surging



## GAR (Nov 7, 2014)

I have a Honda HS622 that I am tuning up. I have pulled and cleaned the carburetor using OEM Honda gasket kit, replaced gas line with OEM gas line & the inline fuel filter, replaced spark plug and changed the oil. But for the life of me I can figure out why it’s still surging. I have pulled the carb again and doubled checked and cleaned it again, I have checked to make sure I am getting good fuel flow, I have checked with carb fluid for air leaks, i changed spark plug twice, I checked compression and the valve lash.....Nothing I am doing is helping. Any advice with this issue would be greatly appreciated. I am including this video off my security camera, if you turn your sound up you can here it. It’s not surging badly but enough to make me crazy...lol
.


----------



## orangputeh (Nov 24, 2016)

GAR said:


> I have a Honda HS622 that I am tuning up. I have pulled and cleaned the carburetor using OEM Honda gasket kit, replaced gas line with OEM gas line & the inline fuel filter, replaced spark plug and changed the oil. But for the life of me I can figure out why it’s still surging. I have pulled the carb again and doubled checked and cleaned it again, I have checked to make sure I am getting good fuel flow, I have checked with carb fluid for air leaks, i changed spark plug twice, I checked compression and the valve lash.....Nothing I am doing is helping. Any advice with this issue would be greatly appreciated. I am including this video off my security camera, if you turn your sound up you can here it. It’s not surging badly but enough to make me crazy...lol
> .
> https://youtu.be/ssefeXpFDKQ


did you remove main jet, emulsion tube , idle jet , and clean out all holes ? how about that tiny 1 by 4 mm Oring that goes on the idle jet.? i change that if it's flat or deformed.


----------



## GAR (Nov 7, 2014)

orangputeh said:


> did you remove main jet, emulsion tube , idle jet , and clean out all holes ? how about that tiny 1 by 4 mm Oring that goes on the idle jet.? i change that if it's flat or deformed.


Yes I cleaned everything very well, I completely took apart carb and ultrasound cleaned it. Before reassembling I spray it out with carb cleaner and blow it out with air gun just to be extra certain it clean. I replaced all the o rings, gaskets....etc.
.
Ok so I messed with it a little more tonight trying to diagnose what exactly it’s doing. This is so frustrating, I have tuned up hundreds of blowers so it’s not like I am new to this stuff.....Ok I just found that when I turn the gas supply off to the carb that the engine starts to smooth out....Ummmmmm. So this would be a flooded float or float pin not seating.....Right? I will take the carb bowel off tomorrow and check these things. There is definitely something dumb that I am missing. This issue could all come down to a big old brain fart....lol


----------



## orangputeh (Nov 24, 2016)

GAR said:


> Yes I cleaned everything very well, I completely took apart carb and ultrasound cleaned it. Before reassembling I spray it out with carb cleaner and blow it out with air gun just to be extra certain it clean. I replaced all the o rings, gaskets....etc.
> .
> Ok so I messed with it a little more tonight trying to diagnose what exactly it’s doing. This is so frustrating, I have tuned up hundreds of blowers so it’s not like I am new to this stuff.....Ok I just found that when I turn the gas supply off to the carb that the engine starts to smooth out....Ummmmmm. So this would be a flooded float or float pin not seating.....Right? I will take the carb bowel off tomorrow and check these things. There is definitely something dumb that I am missing. This issue could all come down to a big old brain fart....lol


yup. sounds like overfilling. I'm the same way. have done hundreds and sometimes it's something simple. one time i put bowl on backward and was wondering why it was leaking from top.

ya, take a time out and revisit with fresh eyes.


----------



## ST1100A (Feb 7, 2015)

It sounds like the slow jet is clogged. Most people do not know about the tiny hole in the bottom of it, that is where the fuel goes through, the big hole is for the air to mix with the fuel.
As O.P. mentioned, check the tiny "O" ring on the jet, many times it gets damaged when re-installing the little black plastic slow jet. I always put a light coating of silicon grease on it before I install them.
The engine might sputter a little bit until it rinses off the grease at first, then it will clear up and idle fine, and no surging at full throttle.
When the engine is running full throttle with "No Load" it is taking most of its fuel from the slow jet because the throttle plate is barely open, when under load it opens further and then it takes fuel from the main jet due to the governor opening the throttle plate further.


----------



## Snowbelt_subie (Dec 20, 2016)

GAR said:


> Yes I cleaned everything very well, I completely took apart carb and ultrasound cleaned it. Before reassembling I spray it out with carb cleaner and blow it out with air gun just to be extra certain it clean. I replaced all the o rings, gaskets....etc.
> .
> Ok so I messed with it a little more tonight trying to diagnose what exactly it’s doing. This is so frustrating, I have tuned up hundreds of blowers so it’s not like I am new to this stuff.....Ok I just found that when I turn the gas supply off to the carb that the engine starts to smooth out....Ummmmmm. So this would be a flooded float or float pin not seating.....Right? I will take the carb bowel off tomorrow and check these things. There is definitely something dumb that I am missing. This issue could all come down to a big old brain fart....lol



so does it smooth out if you start giving it choke? that would indicate its lean. if not i suppose it could be rich. i have never seen that really.

what about when your blowing snow and under load ? if it doesn't surge that would indicate its the low or idle circuit is at fault and the main circuit is good.

it seems you have done your due diligence. sometimes it might be easier to buy a cheap replacement carb off ebay or amazon and put it on and see if that works.


----------



## Snowbelt_subie (Dec 20, 2016)

i just listened to the video you posted. that defiantly isn't a traditional lean surge. its more of a engine miss IMO.


----------



## orangputeh (Nov 24, 2016)

Snowbelt_subie said:


> i just listened to the video you posted. that defiantly isn't a traditional lean surge. its more of a engine miss IMO.


I was thinking the same thing until he mentioned it smoothed out when he shut off gas valve. if the bowl is overfilling would the engine run like it had a miss? or too much gas getting to it?


----------



## Snowbelt_subie (Dec 20, 2016)

orangputeh said:


> I was thinking the same thing until he mentioned it smoothed out when he shut off gas valve. if the bowl is overfilling would the engine run like it had a miss? or too much gas getting to it?



you know im not sure ive had experience of leaky carbs on 2 cycle toro's but they seem to run fine if you can get them started. they start hard like they are flooded (which they are lol).

if i were im i would buy a cheap carb and be done with it. it seems like he tried and spent more time than i would have messing with it.


----------



## ST1100A (Feb 7, 2015)

That miss sounds more like an ignition miss-fire. Bad plug wire or ignition coil arcing at high speed. Check the ground wire for the coil and key switch, the key switch or terminal could be going bad and don't forget to check your valve clearance.


----------



## GAR (Nov 7, 2014)

I am happy to report that the problem is solved, first off yes I should have just bought a replacement carb off amazon or a full rebuild kit for the carb. It needed up being the pilot jet, the hole on the bottom of it was damaged or drilled out way to much. I did not do this, I acquired this machine running poorly. So I assume someone down the line did this. But it was such a small detail I did not catch it. I cleaned and rebuilt the carb using only a gasket kit.....Live and learn I guess. But I am happy that I am now the proud owner of a Honda HS622 that runs perfect now. Thanks for all the advice guys!


----------



## ST1100A (Feb 7, 2015)

The 622 is a tough little machine. Glad to know you got it fixed. Sounds like someone screwed up the pilot jet by enlarging the jet hole, its a very tiny hole, .35mm. Honda makes a special jet cleaning tool for it. Never use a welding torch tip cleaner, or you will ruin it in a big hurry. That's what they probably did to it or drilled it out with a micro drill and did not realize that the jet it tapered like a venturi.
The Honda carburetors are the easiest to rebuild by far than any other carburetors on the market. Use the genuine Honda parts for them, even though the parts are more expensive.
You would know if it is enlarged too much when it idles, it will run too rich and smoke, it won't do much of anything at high speed, meaning it wont make it miss like it was doing in the video.


----------



## ST1100A (Feb 7, 2015)

One other thing that can cause that little bit of miss fire but not too common is running high octane gasoline.
The Honda's were designed for 87 octane gas. They do not have a lot of timing advance built into the ignition system. The lower octane has a faster more complete burn in the combustion chamber, the high octane doesn't burn as fast or complete, actually giving a little bit less power and economy. There is some un-burned fuel coming out of the exhaust valve and when it builds up enough in the muffler it will ignite causing a little bit of a "Bang-Pop-Misfire sound" when it builds up enough to ignite.
It does not happen too often, but it can happen, and most of the time when it does, the engine still seems to run with enough power and it is usually noticed when the engine is not under much of a load.
When it does happen, it is usually intermittent miss-firing sound or a popping sound from the muffler and sometimes you will notice the muffler glowing red from the extra heat caused by the fuel burning in the muffler that did not burn in the combustion chamber of the engine.
It happens more when using high octane fuel than low octane fuel, it doesn't happen all the time but it can happen.


----------



## orangputeh (Nov 24, 2016)

good news. good reason to check the simple things first and work your way up. ya , i never clean those plastic idle jets with anything but carb cleaner andcompressed air.

can u believe Honda charges $17 for these suckers? more than a whole chinese carb


----------



## tadawson (Jan 3, 2018)

I had one of those die on an older mower (20 years or so). It was surging, but the pilot jet did not seem obstructed (could see light through a smooth hole clearly), but rather seemed to have shrunk from all the years in fuel. Replaced it and back to perfect . . .


----------

