# LCT Engine with Idle-Down Issues



## SnowH8ter (Oct 8, 2018)

I will preface this by stating that I’m overall quite pleased with the big Husky’s (ST330P) performance. The 369cc LCT engine starts reliably and runs strong – she’s got more than enough grunt. However, the engine exhibits some rather peculiar operating characteristics. 

The engine throttle is configured with what LCT refers to as an “Idle-Down Control Ring” and the engine manual describes its operation thusly: “The Idle-Down Control Ring sets engine speed from high-speed to low-speed. Rotate the ring clockwise, “RUN” position for high-speed. This control MUST be set in the “RUN” position for starting a cold engine. By rotating the ring counterclockwise, “IDLE” position, will allow your engine to run at low-speed. DO NOT OPERATE EQUIPMENT IN THE IDLE POSITION. Note: the idle-down control is intended to be either in “RUN” or “IDLE” positions only.”

The idle-down feature appears to work as designed, but… only when the engine is cold. Typically, upon cold engine start and after coming off choke, I rotate the throttle control ring to the IDLE position for the engine to warm. The engine speed at this point is about 2000 rpm, which is what LCT specifies (2050 +/- 50 rpm) as idle speed. After 30 or so seconds running at idle, and with no operator interaction, the engine speed gradually begins to increase. Within two to three minutes, the so-called idle engine speed has increased to about 3300 rpm. What the heck…? Engine speed with the throttle control ring set to RUN is between 3600 & 3700 rpm. So, in effect, rotating the control ring from IDLE to RUN to IDLE while the engine is warm will give ya, at best, a 300 rpm difference. Hmmm…

The other peculiar characteristic is revealed upon restarting the engine when it’s warm. It ain’t gonna happen with this particular engine if you follow the steps in the OM. I discovered, quite by accident, that the throttle control ring must be in the IDLE position for the engine to restart when it’s warm. If the throttle control ring is in the RUN position, or somewhere in between, you can yank/crank till the cows come home, but the engine will not start.

These anomalies are consistent and do not appear to vary with temperature or operating conditions. They are so consistent that one could be inclined to think that the engine was designed to operate this way. Dunno… something ain’t right. The Husky dealer I purchased the beast from has to date been unresponsive relative to my queries re the foregoing. I plan to remove the heat box once it warms up a wee bit so I can observe what the carb is doing during these events. In the interim, and appreciating that Husqvarna is not the only user of these engines, I’m open to any and all advice the forum members may be willing to offer up.

Thanks!


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## tadawson (Jan 3, 2018)

All I can tell you is that the LCT369 on my Ariens works as it should - I always get idle, and can always start in full. . . .


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## JLawrence08648 (Jan 15, 2017)

I'm not familiar with your particular engine, I'm familiar with the operation of engines in general.

Do you have a manual choke? Or does the operation of the throttle ring also operate the choke at the same time? The latter is what it sounds like.

Taking off the carb cover is the first place to start.

When warmed, I would consider lowering the idle.

I would also adjust both the low and high mixture screws. With the pulling and pulling, it sounds like the mixture screws are off a little. A shot in the dark, replace the spark plug.


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## cranman (Jan 23, 2016)

What does the idle down control ring look like? I have a 208 cc engine I bought off e-bay that has a red knob on top of the aircleaner that looks like it redirects the air into the aircleaner depending on position, but I have no idea of its function or how to use it....


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## tadawson (Jan 3, 2018)

If this is like the Ariens, choke is manual with a ring concentric and outside the throttle knob. Doubtful you will find any mixture screws on anything this new . . . .

If new, it's a dealer/warranty problem, plain and simple . . .


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## cranman (Jan 23, 2016)

I answered my own question by looking up the model on the website that sold it through E-bay It is a combination winter/summer engine that allows you to bypass the air cleaner for winter use and utilize it for summer use......great concept! I just ordered a second one. I tried out the first and it was great on a 10000 series Ariens. The only negative is the shaft is 25 mm which is a few thousandths smaller then one inch...I solved it by using a couple of strips of aluminum flashing as shims with a 1 inch pulley....worked slick. Can't beat this deal for 79 dollars delivered!


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## Town (Jan 31, 2015)

My LCT 414 cc engine has the red choke knob on top and the grey throttle ring outside it. It starts hot or cold in the full throttle position. There are no mixture screws for adjustment. The mixture is set perfectly at the factory, no need to change it. Engine idles smoothly and quietly at 2,100 rpm, so I would not lower it.


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## Lottstodo (Feb 16, 2018)

It sounds like a dirty carb probably not bad, but enough to keep it from performing as it should. 
My ariens with a 291 LTC w/ idle down carb did the same thing the second season. Not sure why, gas drained everything wiped out but it did. 
What I did was take stp automotive fuel injector cleaner and mixed it 2x the amount as read on label ( you have to do a little math) as it is for larger tanks , start it let it warm up , then move it through the throttle positions several times then shut it off, let it set a couple days and start it and run it as you want still go through the throttle positions several times. Mine cleared out in 5 min the second time it was started and I have made this procedure a part of set up every year it has never did it since, and I have never had to pull the carb.

STP fuel injector cleaner comes in a small bottle is a very concentrated cleaner, and I as well use it when I have real nasty carbs to try to save and brush it on with a Q tip and let it set. 
Some of the new stock snowblowers at the dealer may be 1-2 years old (stock) that they put fuel in and neglected to perform proper storage during off season storage ,, found this to be true on many many units and not just, ariens , craftsman , huskies, mtd. etc.


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## SnowH8ter (Oct 8, 2018)

tadawson said:


> All I can tell you is that the LCT369 on my Ariens works as it should - I always get idle, and can always start in full. . . .



That's good to know - thx!


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## SnowH8ter (Oct 8, 2018)

tadawson said:


> If this is like the Ariens, choke is manual with a ring concentric and outside the throttle knob. Doubtful you will find any mixture screws on anything this new . . . .
> 
> If new, it's a dealer/warranty problem, plain and simple . . .


Yep, same as Ariens - integrated choke and throttle control. Warranty issues can be troublesome when the selling dealer has been unresponsive to multiple queries. Next closest dealer is two hrs away. Not prepared to exercise that option just yet - that's why I is here.


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## SnowH8ter (Oct 8, 2018)

Town said:


> My LCT 414 cc engine has the red choke knob on top and the grey throttle ring outside it. It starts hot or cold in the full throttle position. There are no mixture screws for adjustment. The mixture is set perfectly at the factory, no need to change it. Engine idles smoothly and quietly at 2,100 rpm, so I would not lower it.


Indeed, the 369cc engine is quite similar to the 414cc engine and to the best of my knowledge, has no provision to adjust fuel delivery. I'll confirm that once I get the heater box off.


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## SnowH8ter (Oct 8, 2018)

Lottstodo said:


> It sounds like a dirty carb probably not bad, but enough to keep it from performing as it should.
> My ariens with a 291 LTC w/ idle down carb did the same thing the second season. Not sure why, gas drained everything wiped out but it did.
> What I did was take stp automotive fuel injector cleaner and mixed it 2x the amount as read on label ( you have to do a little math) as it is for larger tanks , start it let it warm up , then move it through the throttle positions several times then shut it off, let it set a couple days and start it and run it as you want still go through the throttle positions several times. Mine cleared out in 5 min the second time it was started and I have made this procedure a part of set up every year it has never did it since, and I have never had to pull the carb.
> 
> ...


Interesting, thanks for sharing that. The blower was in fact a year old when I picked her up last Oct. However, it was in a crate the day before I took it home. That doesn't preclude the possibility that there's something untoward residing in the carb and is certainly something to probe. The operating anomalies were evident while burning through her first full tank.


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## SnowH8ter (Oct 8, 2018)

JLawrence08648 said:


> I'm not familiar with your particular engine, I'm familiar with the operation of engines in general.
> 
> Do you have a manual choke? Or does the operation of the throttle ring also operate the choke at the same time? The latter is what it sounds like.
> 
> ...


Apparently a non adjustable carb. The choke is 4-step manual affair. The throttle control ring and choke are integrated as a shaft within a shaft arrangement (choke center/throttle outer). Choke control is directly connected to the choke plate. A series of linkages connects the throttle shaft to the throttle plate. Plug is good - good spark cold engine and warm.


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