# HS80 dies under load until warm



## Snow800 (Mar 14, 2017)

My Honda HS80 doesn't run like it used to. It starts okay, using choke as it always did. After 10 or 15 seconds the choke can be turned off and it runs at idle and full speed just as it used to, provided there's no load. 

But if I engage the auger it immediately begins to die. Releasing the auger doesn't help. It continues to slow and die and unless I immediately choke it again and switch the choke on and off it just slows down and stops. It may even backfire once, although that's not common. 

If I run it partly choked for 3 to 5 minutes, and carefully start the auger and take very small bites of snow, it will heat up and after ten minutes it then runs fine for the rest of the session. It may have a bit less power than it used to, but that's hard to judge. 

I know it sounds like it's ok and just needs to warm up, but this is a clear change from before. It never ever would die, and never do the slow slide to dying even with the new extra load removed. 

I've  removed the carburetor and carefully cleaned it twice. The last time it was in a warm ultrasonic carb cleaner bath for 18hours.

Do the symptoms ring any bells with the experts here? 

Should I be looking at valve clearances? Any other thoughts? I can continue to use it this way... it just needs to start and be carefully warmed up, with care used to get the engine loaded, but I'd really like to figure this out. 

Thanks for any help.


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## Mikeleti (Feb 15, 2017)

Still sounds lean on high speed to me.
Fixed jet or can you adjust the main jet in center of fuel bowl??


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## YSHSfan (Jun 25, 2014)

I agree with above, sounds like a lean condition.


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## Snow800 (Mar 14, 2017)

Mikeleti said:


> Still sounds lean on high speed to me.
> Fixed jet or can you adjust the main jet in center of fuel bowl??


I thought it might be a bit lean, too, and wondered if it might be leaking at the gasket between carb and engine intake, so I added a liquid gasket when I reassembled it after the first carb cleaning. 

This time I didn't bother. I suspected main jet, too, so spent time inspecting it. The jet looks fine. It's a screw in replaceable brass jet at the bottom of the main brass jet tube. Both have been inspected under magnification and look great. The only adjustment to the main jet is to replace the brass jet piece. There is one adjustment, a brass needle, but I think it's an idle jet. There's a removable plastic jet (marked 38) and some tiny jet holes under a cap. The cap was removed and the jet holes cleaned, then the cap was replaced and sealed.


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## Fat City (Feb 11, 2017)

Does your governor move when it dies ? Could be a simple governor adjustment .


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## all3939 (Dec 21, 2014)

When you put the carb back together did u orient the bowl back to its proper position. I if not it won't be able to get enough gas for high idle.


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## tabora (Mar 1, 2017)

I've had that set of symptoms when there's a little water in the fuel at the bottom of the tank/carb bowl. I drain the carb bowl plus a little more from the tank and then it straightens right out. Otherwise, I agree with the lean diagnosis.


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## Snow800 (Mar 14, 2017)

On the bowl orientation question, I didn't notice any orientation marks. I put it back close to the way I found it. But if that was the problem, would it run after warming up? My symptoms mostly (completely) disappear after it's fully warmed up. 

As to lean.... Hmmmmm. Any suggestions on tracking it down? I tried very hard to seal the carb to engine seal the first time. The secknd time I just used the original gasket. Is the carb fuel bowl gasket likely to be a problem? Mine looked good, but there were a few deposits on it I could not fully remove and it is old. 

On the governor issue, I'm not sure how to check it. 

I really appreciate the suggestions and comments. 

Anyone want to suggest a test or next step in diagnosing or fixing it?


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## Mikeleti (Feb 15, 2017)

Is there a fuel filter in there somewhere, looks like there may be one incorporated in the fuel inlet assy. There may be one on the line at the tank too. 
Try taking the drain plug from the bowl and see if a reasonable amount of fuel continues to run out. (Maybe a shot glass worth every few seconds)
The fuel supply may not be keeping up with the demand.
Remove the fuel line from carb and gently blow back to the tank and make sure it is clear.

Keep looking, you'll find it.

Mike


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## Snow800 (Mar 14, 2017)

The first go round I pulled the gas tank. It has a filter at the outlet and I cleaned it. The second go round I just checked the fuel flow. I'm not convinced it's up to a few shot glasses a second. Perhaps half that, but I can't be sure. I'll check it more carefully.


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## Mikeleti (Feb 15, 2017)

Shot glass every few seconds!!!!


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## Snow800 (Mar 14, 2017)

Will check for the shot glasses and may have one myself ... afterwards.


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## drmerdp (Feb 9, 2014)

It could be a fueling issue but I would check the valve lash for good measure. OHV engines tend to have too much lash over time. The heat and expansion in those 10 minutes would have a positive effect.


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## Snow800 (Mar 14, 2017)

It's not fuel. I'm getting good flow. 

Does anyone know where to get the valve lash settings? The fact that the problem goes away as it heats up seems significant, but I'm not sure if my symptoms match what happens with valve clearance problems.


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## orangputeh (Nov 24, 2016)

if it is a lean condition as some suggested , how does a lean condition occur over time? or all at once?

if it is getting enough fuel why would it die or slowly die under load?

would that be a compression issue? don't know the valve lash numbers but they are in the pdf file you can get online.

have to check clearances when cold.


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## Snow800 (Mar 14, 2017)

orangputeh said:


> if it is a lean condition as some suggested , how does a lean condition occur over time? or all at once?


To be clear, Shortly after start it idles and/or runs no load full speed without problem. Applying a load during this period is where the problem occurs. Just spinning the auger is enough to couse it to die over a period of 5 to 10 seconds. Releasing the auger won't stop it from dying. Choking again usually won't stop it either. Only cycling the choke on/off will coax it back to running again. 



> if it is getting enough fuel why would it die or slowly die under load?


Both of these are good Qs. Its why I wondered about valve lash. That struck me as something that might change as it warms up. 



> would that be a compression issue? don't know the valve lash numbers but they are in the pdf file you can get online.
> 
> have to check clearances when cold.


Compression could change over time I suppose, and that might match my impression that power is lower, but it runs well after its fully warmed up. Nothing I do then can cause any problem. No stumbling or hesitation or backfire. 

I'm leaning toward a valve issue. I'll check the engine model and go to the European Honda site that has good engine info.


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## Snow800 (Mar 14, 2017)

It has a GX240 engine. Intake clearance 6 thou inches plus or minus a thou. Exhaust is 8 thou, also plus or minus one thou.

Compression 81-121 psi. 

Spark gap 28-31 thou BPR5ES (NGK)


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## Snow800 (Mar 14, 2017)

*Update*

I went to remove the spark plug in order to locate top dead center and check the valve lash. The first thing I noticed was the spark plug seemed a bit loose. next I cleaned and checked the spark gap which was a tad low.

As long as the spark plug was out, I decided to check compression. Compression was 60 PSI. very low. Next I squirted some oil into the cylinder and compression initially jumped to 110 PSI. then it dropped to 95 PSI and I never saw a higher or lower reading in the next three tests. I started the engine again in order to burn out all that oil and after a lot of smoke and backfiring, jumping, hesitating and cycling the choke I got it started and from then on it ran just as it had before with good power but not great.

I couldn't tell if the initial period adter starting was still low power as it took a long time to get it running and by then it was pretty warm. 

since the engine was now warm, I couldn't do the valve lash measurements. my compression tester is it least 30 years old. I can't be sure how decent it is today but the measurements with oil in the cylinders seems reasonable so my guess is I've got worn Rings / cylinder walls. does this sound reasonable for my symptoms? does the engine warming up produce a better seal with the oil Splash lubrication system that might account for the low power during initial startup?


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## orangputeh (Nov 24, 2016)

Snow800 said:


> It has a GX240 engine. Intake clearance 6 thou inches plus or minus a thou. Exhaust is 8 thou, also plus or minus one thou.
> 
> Compression 81-121 psi.
> 
> Spark gap 28-31 thou BPR5ES (NGK)


oh, just saw the above post that you did a compression test. obviously you have to check the valve lash next.

hope some motor experts chime in as this is a very interesting problem. I haven't run into this situation but I want to know what causes it.


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## Snow800 (Mar 14, 2017)

By eye I carefully set the piston to the top of the compression stroke. I measured the intake and exhaust valve clearances. I did this twice. The exhaust clearance was 4 thousandths. The intake clearance was 2.5 thousandths. I set them to eight and six respectively.

I don't have a manual and couldn't figure out an easy way to locate the position on the crankshaft for measuring the valve clearances. However I did try other positions of the crankshaft and couldn't find any point at which the clearances were any greater than measured above.

I started the engine. The result was terrible. The engine coughed, choked and backfired repeatedly through the carburetor. It was very difficult to get it to run. I never got it to run smoothly on the choke. It was like it was missing and unable to reach full operating speed. This continued for three or four minutes. Finally it smoothed out and thereafter ran smoothly with the choke off.

However when I engaged the auger, it coughed and tried to die as previously described . Again I had to cycle the choke on and off rapidly to keep it alive. It died once and I restarted and went through the same thing for a minute or two. Finally it was warmed up. It drove away and had good power. It cut through piles of icy snow and you could hear the engine digging in deep and opening the carb for more power which it had.

Any suggestions? Should I lower the valve clearances. At least it started previously and there was far less backfiring through the carb.

Should I consider replacing the carburetor? Do I have to rebuild the cylinder for higher compression? Could there be an electrical problem causing missing until it is warm?


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## Snow800 (Mar 14, 2017)

I have a Honda 2 HP outboard that just wouldn't give me full power. For 2 years I struggled with it. It was usable, but not fun. I must have rebuilt that carburetor 3 or 4 times spraying 4 or 5 bottles of carb and choke cleaner through all the passages. Nothing helped. 

Finally I took the carburetor off put it into the carb cleaner soak bath and into the ultrasonic cleaner. When I put it back together the engine ran beautifully. But that's what I did to the carb on the snowblower. I'm not sure I can do any better job of cleaning or repairing the carburetor.

Now I'm in a similar situation I can use the snowblower. It's just not fun to get it through the initial starting stage. But once it's started it seems to run great. Does that sound like a carburetor issue to you?

It does strike me as possibly a choke circuit problem with the carburetor. All of the problems occur when the choke and choke circuit are in use. I just hate to try and clean it again.

Does it sound like I set the valve clearances correctly? What's with all of the backfiring through the carburetor which became significantly worse after adjusting the valves?


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## Snow800 (Mar 14, 2017)

The engine manual I found suggests checking head bolts if compression is low. I've never heard of them loosening, but I suppose it's worth doing. They would tighten and seal up the head as the engine warmed up, but I don't know if it matches my symptoms.


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## orangputeh (Nov 24, 2016)

what would a new carb cost compared to all the time you have spent trying to clean, take apart , etc.?

I don't remember if you changed the pilot jet . I'm sure you cleaned it. have had similar issues with several 1132's that had backfiring issues and had to be run on partial choke or else it would die.

I changed the plug, cleaned the pilot/idle jet and that did not work so just changed the pilot jet for $16 and then both machines ran excellent. however, both machines had good compression to begin with.

not sure about your valve adjustment. I would check it again. 

are you saying that once it's totally warmed up now , it works fine? or does it still almost die when you engage the augers like before?


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## Snow800 (Mar 14, 2017)

orangputeh said:


> what would a new carb cost compared to all the time you have spent trying to clean, take apart , etc.?
> 
> I don't remember if you changed the pilot jet . I'm sure you cleaned it. have had similar issues with several 1132's that had backfiring issues and had to be run on partial choke or else it would die.
> 
> ...


When it's warmed up it runs fine. Perhaps a bit less power than I remember, but not much. It will start and stop the auger and tackle heavy piles of ice laden snow. You can hear the governor open the throttle to maintain rpm. If not for the init ial warmup period, it would be ok.

I'll check and adjust the valves again just to see if that helps. I've never run anything through the main jet, but visually it looked great and it spent 18 hours in a warm ultrasonic bath of Berryman's carb cleaner. It should be good.


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## orangputeh (Nov 24, 2016)

does that have the gx160 honda motor?

they have carbs for that on amazon for less than 10 bucks. i bought a carb for my hs624 for $15 on ebay.

it's a gx240. I would buy a clone carb for it and try. maybe something is worn or damaged in that 33 year old carb.


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## Snow800 (Mar 14, 2017)

orangputeh said:


> does that have the gx160 honda motor?
> 
> they have carbs for that on amazon for less than 10 bucks. i bought a carb for my hs624 for $15 on ebay.
> 
> it's a gx240. I would buy a clone carb for it and try. maybe something is worn or damaged in that 33 year old carb.


 I'll look around for a clone carburetor. I reset the valves and decreased the clearance by one thousandth of an inch on both. That still puts them just within spec. 

I also rechecked the compression as long as I had the spark plug out. This time I was able to get a better seal between my ancient compression tester and the block. This time compression was 82 PSI for every test. That's also just within spec and I wouldn't be surprised if compression was slightly higher with a new o-ring and or new compression tester.

The engine still coughed and backfired a bit, but only for about a minute and then it seemed to run fairly well. It still had a bit of trouble cranking up the auger, but the entire warmup period was reduced from ten minutes to two or three minutes. 

Most of the trouble seems to be when I have it choked. I wouldn't be surprised if a new carburetor will solve that.


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## cpchriste (Jan 19, 2014)

I know this thread is 3 years old BUT for future reference:

These symptoms are very similar to my HS55 with a bad plug cap which allowed intermittent arcing to the valve cover whenever the engine was put under load.
The plug cap is only $5-8.
Diagnose by running in twilight with covers off.


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## SkunkyLawnmowers (Oct 18, 2018)

cpchriste said:


> I know this thread is 3 years old BUT for future reference:
> 
> These symptoms are very similar to my HS55 with a bad plug cap which allowed intermittent arcing to the valve cover whenever the engine was put under load.
> The plug cap is only $5-8.
> Diagnose by running in twilight with covers off.


Excellent diagnostic work, thanks for the details


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