# 524SWE - vibration at idle



## DennisP (Jan 10, 2016)

Hey guys, got the new (to me) 524SWE (2011 model with 208cc engine), put in a new spark plug, changed the oil to synthetic, filled the tank with fresh gas and seafoam. There was about 1/8th of a tank of who knows what in it when I got it.

Well, it started right up, ran at full speed with 1/2 to 1/4 choke, but when I went to close off the choke, it started surging. I let it run with 1/4 choke at full speed for a while to warm up, then closed the choke and it did better, but still surged a little every now and then. I am hoping that it is just gunk in the carb and good gas with seafoam will do enough to clean it all out. It was getting late so tomorrow I will run it at full speed for a while and use of the gas in it.

At full speed it it runs pretty well, smooth, not major vibration. Now, when I put it to idle, it idles right down and runs consistently. The issue I have is that it seems to have quite a vibration at idle speed compared to full speed. Is that normal for this engine?

I don't have anything to compared it to, since my other Cub Cadet, a 2015 year 221 LHP, which has the same motor, but it doesn't have a throttle, so it runs at full speed all the time.

Now, I have no problem if this is the way the engine is supposed to run, but if not I want to figure out what is up before I need to rely upon it.

The only thing that was kind-of disturbing is when I drained the oil it was a little dark with almost a greyish tone to it. Normally that isn't good as that could be metal, but considering how little use this snowblower had, it might just be the very first oil change it has ever had, which makes it much less of a concern. The original spark plug was black and wet when I pulled it, so it most certainly needed to be changed.

Mu concern is that the vibration at idle is because of some serious engine problem (like a rod bearing issue). Like I said it runs quite a bit smoother at full speed, so I guess I am not going to be too worried to start with, especially if others mention that theirs also vibrates at idle like mine.

I know enough about high-performance V8s and such, but small single cylinder engines are kinda new. Considering since I bought a house I now have a Brute lawnmower with a Briggs engine, a plate compactor with I believe a LCT engine, a pressure washer with a Subaru engine, my Cub Cadet 221LHP, my new Cub Cadet 524SWE, and the older snowblower I am building from the ground up with a Tecumseh engine, I figure I had better get a handle on OPE engines pretty quick.

Any feedback on the way everyone elses 524SWE 208cc engine runs would be appreciated.


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## DennisP (Jan 10, 2016)

One other thing I forgot to mention is the choke seems kinda "funky" to me. It has a full 90 degrees of swing to it, from straight up and down vertical "open" to a horizontal side-to-side "closed" position. The choke scale label only shows a 60 degree swing or so and I noticed the detent "clicks" of the choke only seem to operate within that range.

I am just wondering if the choke knob on mine is operating properly, or if it is spinning on the shaft and is going past the actual close position and/or past the full open position as well.

I tried to pull the choke knob off, but it doesn't seem like it wanted to come off.


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## motorhead64 (Dec 15, 2013)

Hi Dennis 
Check your engine attachment bolts to make sure they're snug. Also check other attachments that can rattle. Engines are more prone to noticeable vibrations at lower rpms. On the choke, it is possible to move beyond the last detention on a choke knob. Have to be careful as the butterfly can be damaged from moving too far. MH


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## caddydaddy (Dec 10, 2014)

The choke on mine does have about the 90 degrees of travel like you said.

Is the idle set too low on this engine? Single cylinder engines will shake a lot if the idle is too low.


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## DennisP (Jan 10, 2016)

Thanks guys, I will be checking all the bolts on the unit today. I will also be completely greasing everything as well...

I will have to pull the exhaust shroud and checkout the actual physical butterfly action. Probably a good time to spray some carb cleaner directly into the throat of the carb as well. I am hoping that it sitting with the new gas and seafoam mix will cleanup whatever deposits the carb has accumulated from it not being used for so long. The inside of the gas tank was pristine, so that was a good sign.


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## caddydaddy (Dec 10, 2014)

If it's been sitting for a few years, it might not hurt to pull the carb off and give it an inspection and a cleaning.


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## DennisP (Jan 10, 2016)

So, just got done doing some work on it... All the bolts are tight. One locating bolt on the auger cable bracket was stripped, so I fixed that.

upon inspection there was a few problems that culminated in the original owner probably being pretty pissed off. Turns out one of the auger cable pulleys was binding on the bracket itself (probably a poorly toleranced bracket), so I ground the one side of the pulley down and it was fixed, but the way it was the auger never really released. which means the cable itself was never adjusted properly. All this caused the belt to get eaten by the pulleys as there was quite a bit of rubber and plastic inside the pulley cover and area. I ended up moving the pulley bolt to the inside location which tightened up the belt quite a bit, coupled with a properly adjusted cable and then is plenty of pressure on the belt and it positively engages.

I also found all the rest of the cables were not adjusted properly, so I took care of that.

Then I ran the engine for a good hour. I looked at the choke and it does work within full swing of the knob, so there is no over-pressuring either way. The engine works great within that 60 degree range, with the top of the range (showing run on the label) it is one detent off full open choke, so I am thinking they know these motors run lean and if you use it within the range of the label it is all good.

Running at the run-location of the label it sounded exactly like my 221LHP with it's choke in run as well. Not a single sputter, no surge. When you activated the augers you could tell the engine had a load applied but in no way sounded labored.

So, I shut it all down, put the pulley cover back on (which keeps the auger pulley belt from slapping) and then looked at the auger handle itself because it was squeaking and seemed a like it might need a little tightening... WRONG. I snapped the shoulder bolt off. So now I get to drive 23 miles each way to go pickup the replacement parts. I will pull the plastic clutch off the rod to make sure nothing else breaks that I might need...

But, with a big storm on the horizon next week, I don't want to take the risk of ordering something online and having it not get here in time.


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## bad69cat (Nov 30, 2015)

Ahh pooop! Sounds like a Monday thing! If the bolt is going into aluminum it may have been corroded up a bit in there. I always use anti-sieze in bolt like that. Never hurts to chase the threads if it came out hard to start with..... I don't blame you for waiting on the mailman to deliver the goods. Looks like Wed could finally be a good one if it pans out! Trying not to gt my hopes up to much ;>P


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## DennisP (Jan 10, 2016)

Well, it is all repaired and good to go...

Turns out I should have found this local supplier before I got too far in my Craftsman parts ordering... He is a somewhat local small-shop and his prices are great... I would have gladly given him all my business...

So, I picked up the nut and bolt (neither are aluminum, but they are mild steel) as well as a new auger belt. Got it all installed and it runs really well. I am not thrilled with the tension on the new belt , as it is barely better than the old belt, but I don't know if I want to move to the inner tension point so quickly, as I am concerned it might end up putting too much stress on the cable which could cause the cable to break prematurely. But, in any case, the tension on the belt is still way better than the way the original owner had it setup, since at that point there was barely any tension on it at all (the spring on the end of the cable wasn't even getting pulled open.

One thing I did notice is that without the cover on the new belt was grippy enough to keep the augers rotating with the handle released. The plastic cover in an integral part of keeping the belt off the PTO pulley. With the cover in place, once you release the auger level you get a quick slap as the belt settles into the cover and there is no longer motion out of the augers.

While I had the belly-pan off I also cleaned off the excess rubber on the friction disc... There wasn't too much and there is only minimal wear on the friction wheel. You can tell they used it a little, but I don't really think they were inclined enough to even know how to operate a snowblower properly, considering they couldn't set it up, even when they had the manual.

In any case I think I am all set for the impending snowfall... I would love to have my big Craftsman rebuilt and done by then, but with parts still at the machinist, it isn't going to happen that quickly.


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## DennisP (Jan 10, 2016)

Well, I figured I would follow-up on this...

I swapped out the spark plug for a NGK BPR6ES and between that and the seafoam in the fresh gas it has no issues and no surging running with the choke full open (straight horizontal, past the label).

It is also smoother running at idle. No-where near as much vibration, so I am thinking the engine just needed to be run-in and get all the carbon burned off with good gas, seafoam and a good plug.

The original plug was black and wet, so I can only imagine how poor of a life this engine had before I got it and tweaked it. Who knows, maybe it was a bad plug from the factory, since when I ran it at the original owners place it didn't sound good at all, most certainly nothing like it runs now.

As a side-note, for anyone that might find this thread in a search in the future, I can say the NGK plug is a definite update needed for these motors. The 208cc in my 221LHP is running just as nice as I swapped that stock Torch for the NGK in that one as well.


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## jtclays (Sep 24, 2010)

Dennis, Just a thought as I read through some of your posts. Have you ever checked the valve clearance on it? It's at least 5 years old by date and those OHV engines can get a bit funky at that age. They are really easy to adjust if you have the spec's.


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## DennisP (Jan 10, 2016)

jtclays said:


> Dennis, Just a thought as I read through some of your posts. Have you ever checked the valve clearance on it? It's at least 5 years old by date and those OHV engines can get a bit funky at that age. They are really easy to adjust if you have the spec's.


Considering the lack of wear to everything else, I honestly think it has really low hours on it. Especially if it was a bad plug from the factory and never ran right, coupled with improper setup, I can see the previous owners not being happy with it at all.

But, this spring I will look into it and check the valve clearance regardless, so thanks for the tip.


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## caddydaddy (Dec 10, 2014)

Nice! I'll keep the better plug in mind for mine. It seems to run find with the stock plug.
My generator had a Torch plug and it did run much better when I put an NGK in it!


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## DennisP (Jan 10, 2016)

Yeah, I think my plate compactor is a LCT engine with a Torch plug in it. I bought it new backin 2014 for the paver patio build and kept it because I am still redoing paver areas throughout the property (parking slip, front patio, still have to do the front walkway in spring), and this last year it ran "ok" but wouldn't run with the choke off completely.

I must admit, I have zero doubt it might be my fault for not using stabilizer, but I figure this spring I will pull the carb off, clean it all, put a fresh NGK plug in and change the oil. I may even try to find the specs for the valve lash and check that as well.

Hmm, I wonder if anyone as a suggestion for the best plug for a Subaru 4-cycle??? I have one of those in my 3100psi pressure washer (bought that just before winter, got a great deal on it, and it even has a built-in battery and electric start). I know I shut off the fuel on that one and ran it until it stopped running. I only put like 1/4-1/6 tank of gas in it and ran it for a short time, so I am thinking I might just be able to fill the tank with gas with seafoam and be good.

I will say, it is amazing how many small engines you end up with when you start amassing OPE.

I am definitely going to add a gas-powered trimmer this spring as well.


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## 43128 (Feb 14, 2014)

same thing, an ngk bpr6es. any modern ohv valve or ohc cam engine will use an ngk bpr6es spark plug. in fact, its one of the 2 plugs i keep in stock, ngk br2lm plugs for flathead engines and ngk bpr6es plugs for ohv engines. besides trimmers plugs, those are the only plugs you will ever use in modern power equipment


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## DennisP (Jan 10, 2016)

43128 said:


> same thing, an ngk bpr6es. any modern ohv valve or ohc cam engine will use an ngk bpr6es spark plug. in fact, its one of the 2 plugs i keep in stock, ngk br2lm plugs for flathead engines and ngk bpr6es plugs for ohv engines. besides trimmers plugs, those are the only plugs you will ever use in modern power equipment


Well, it sounds like you deal with this stuff a lot more than I do. Would you have a plug recommendation for a HMSK100-110 engine, and maybe a HSK850?

I was going to use the Champion plug for the 4-cycle and I was going to try a E3.12 plug for the 2-cycle (primarily because that was all Menards had in stock for the 2-cycle). The HMSK 110 is brand new, and the HSK850 is older and I am looking to make that one less smelly while running.


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## 43128 (Feb 14, 2014)

ngk br2lm for both. they can be hard to find in stores so ill usually order a 4 pack on ebay.

NGK 5798 BR2LM Standard Spark Plug | eBay


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