# Surging when cold



## csonni (Dec 26, 2017)

I’ve noticed something when I leave my Honda outside for awhile rather than inside where it’s heated. Running it cold will cause it to surge as though there’s ice in the carb or something. Takes awhile to clear up. My old Honda did that a lot. This only happens when it sits outside for awhile. Maybe it’s getting too spoiled resting in our heated shop?


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## cranman (Jan 23, 2016)

It seems to me that when it is cold it is running leaner, which would cause it to surge....install an adjustable main jet or drill out your main jet untill it runs right........or do what I sometimes do.....put the choke on a little.


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## csonni (Dec 26, 2017)

My larger jet which is on the way should do the trick, then. Honda, shame on you for configuring these machines to run like this!


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## Marlow (Dec 17, 2016)

Are you turning the choke completely off once you start it? If so, don't turn the choke off so quick. Turn it off in a few increments based upon the way the engine sounds and responds. My honda does this and so does my b&s. It needs a bit more choke when cold, kind of similar to automotive engines idling higher until warmed up.


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## orangputeh (Nov 24, 2016)

csonni said:


> My larger jet which is on the way should do the trick, then. Honda, shame on you for configuring these machines to run like this!


what model honda? and what size jet are you putting in? plus , does it run ok after it's warmed up?


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## csonni (Dec 26, 2017)

Marlow said:


> Are you turning the choke completely off once you start it? If so, don't turn the choke off so quick. Turn it off in a few increments based upon the way the engine sounds and responds. My honda does this and so does my b&s. It's normal.


I might not be doing it gradually enough, but the surging lasts for quite some time. Even if I push the choke right away, it shouldn’t take that long for it to even out.


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## csonni (Dec 26, 2017)

orangputeh said:


> what model honda? and what size jet are you putting in? plus , does it run ok after it's warmed up?


Ive got the HSS1332A and I ordered the .041, .042 and .043. I’m still debating if I should put in the .042 or .043.

For some reason today, the surging continued for quite some time. I had shovelled my shop roof off so it was pretty dense snow after it hit the ground. I had to go through it slower.


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## Marlow (Dec 17, 2016)

csonni said:


> I might not be doing it gradually enough, but the surging lasts for quite some time. Even if I push the choke right away, it shouldn’t take that long for it to even out.


It's perfectly normal in cold conditions. Which is why, as you said, when kept in your heated garage it doesn't do it. Nothing to worry about.


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## jrom (Jan 10, 2014)

I'm with Marlow on this. 

If the temps stay below 15°F, I need to keep the choke on for a short while (like 2 minutes or so) before she'll be running smooth...and I mean even under load.

After that, smooth sailing nice Honda GX.


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## orangputeh (Nov 24, 2016)

csonni said:


> Ive got the HSS1332A and I ordered the .041, .042 and .043. I’m still debating if I should put in the .042 or .043.
> 
> For some reason today, the surging continued for quite some time. I had shovelled my shop roof off so it was pretty dense snow after it hit the ground. I had to go through it slower.


OK. ' I'm sure you read that rejetting thread where people changing their jets to a larger size really improved their performance.

that does seem the way to go.good luck.


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## Marlow (Dec 17, 2016)

I can tell you from first hand experience you'll still need to back the choke off in increments after cold starting even with a bigger jet in there. Once you fire it up, leave it. Once it starting surging, back the choke of until it smoothens out. Leave it. Once it starts surging again, back the choke off a bit more until it smoothens out.. Usually it takes 1-3 incremental adjustments until the choke is fully off and everything is smooth. It's not a problem, it's just how it works - especially considering a typical day in Goose Bay is like -30 celcius! LOL That's equivalent to -22 fahrenheit for you Americans.


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## csonni (Dec 26, 2017)

jrom said:


> I'm with Marlow on this.
> 
> If the temps stay below 15°F, I need to keep the choke on for a short while (like 2 minutes or so) before she'll be running smooth...and I mean even under load.
> 
> After that, smooth sailing nice Honda GX.


I’ll keep that in mind next time I fire it up.


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## csonni (Dec 26, 2017)

After adjusting my rpm and changing the oil, I started her up and I must say, she runs smoother when choked a bit. After all, it is minus 20C.


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## drmerdp (Feb 9, 2014)

Did you up the jetting yet?


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## csonni (Dec 26, 2017)

drmerdp said:


> Did you up the jetting yet?


Not yet. The jets are still on their way. I'm wondering if I even need to now after the increase in performance with just the rpm change. But I probably will. Here's my "blurry" plug. She does look lean.


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## drmerdp (Feb 9, 2014)

Definitely change the jet, and keep the rpms up. With the temps that cold, the .043 is definitely the best move.


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## csonni (Dec 26, 2017)

drmerdp said:


> the .043 is definitely the best move.


I have the .041, .042 and .043 coming. I was thinking of going with the .042 rather than chance it of running too rich. If I pull the plug later and see it still on the lean side, I could put in the .043. Good move?


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## drmerdp (Feb 9, 2014)

For your location, really cold temps and tons of snow, I’d go right to .043. But there is no harm in starting with .042

From my experience, a fully broken in gx390 In sub freezing temps really liked the .043.

.042 is a nice stepping stone for engines that don’t get a ton of hours. And for milder temperature regions. Let’s be frank, it will run sooo much better with either jet. 

I personally am running a .042 for the time being because I have barely any hours on my gx390. It I have a .043 jet ready to go once I can hear/feel it needs it.


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## csonni (Dec 26, 2017)

drmerdp said:


> For your location, really cold temps and tons of snow, I’d go right to .043. But there is no harm in starting with .042
> 
> From my experience, a fully broken in gx390 In sub freezing temps needs at least a .043.


From that, I definitely should go with the .043
I bought the thing on Dec. 28 and have 19 hours on it already. And we're going into our snowy season from here on out.

I m a bit nervous with all the experiences of leaks after dropping the bowl. Sounds like an issue with maybe over tightening? Hmm.


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## tabora (Mar 1, 2017)

csonni said:


> I have the .041, .042 and .043 coming. I was thinking of going with the .042 rather than chance it of running too rich. If I pull the plug later and see it still on the lean side, I could put in the .043. Good move?


The .0433 appears to be perfect for my HSS1332 here in Maine at sea level. If you see ANY surging in RPM with the .042, you'll probably want to increase yours as well.


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## sr73087 (Feb 9, 2017)

My HS55 does this as well with the aftermarket carb. I mentioned it to a small engine shop around my area and he said the same thing "they leaned them out so much they surge until warm". So like everyone else said, apparently its normal, unless you want to mess with rejetting but personally I think its easier to just choke it for alittle while while I shovel around the doors and maybe clean off the cars.


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## ZOMGVTEK (Sep 25, 2014)

Unfortunately, its super common for anything with a carb to run lean. This is less of an issue with 4 stroke warm weather engines, but is likely the cause of significant frustration with cold weather engines. Since they're tuned to run slightly lean when fully warmed up, it means they're running extremely lean when started cold. With a 4 stroke, if its surging when cold, its running very lean. If theres a separate choke, you can partially apply it, but ideally you would rejet so it runs slightly rich under full load in your normal operating temps. If you happen to live in an area thats always very cold, youre going to need even more fuel than someone with a more mild winter.

In general, if you want the engine to start and run reliably, just jet it slightly rich. It will use a bit more fuel and have much worse emissions, but it will start and run more reliably across the range of weather conditions. Most people don't use a snowblower all that much anyways, so I dont suspect the downsides are all that significant. Especially since frequently people trash a good machine since its running extremely lean and is hard to start to keep running. The environmental impact of replacing that machine early surely has to offset the increased emissions.


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## tabora (Mar 1, 2017)

I believe that the stock jet for the HS55 was a #70 and the optional high-elevation (leaner) jets were #68 & #65. So, if you go up to a #72 or #73, or one of the adjustables (link below), you should eliminate the surging and also gain some power.

For anyone who's interested, here's an adjustable main jet for under $10... If you're in Canada, I can purchase it on your behalf and forward it. https://www.ebay.com/itm/HF-Predator...YAAOSwF71Z144Y


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## ZOMGVTEK (Sep 25, 2014)

As engines wear they're going to need a slightly bigger jet to maintain the same AFR. I'd say a good starting point for an old engine is ~6#'s larger. If you're surging when cold, might even want to try a big larger than that.

If the machine bangs and pops when its warm outside, its jetted about right for winter service.


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## Freddy Ford (Jan 30, 2018)

ZOMGVTEK said:


> Unfortunately, its super common for anything with a carb to run lean.


100% on the money thanks to the EPA. Anything that is CARB certified (California) is even worse, which the HSS is. You used to see different model designations for equipment that was certified for California and models not certified (chainsaws, mowers, etc). Now most manufacturers have consolidated and offer only the CARB version and we're all suffering for it.


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