Snowblower Forum banner

Snowmaster 724 QXE Surging When Choke Is Off

1 reading
19K views 15 replies 9 participants last post by  tdipaul  
#1 ·
I bought a brand new Snowmaster 724 QXE last October.

Today I had to use it for the first time. I put a new spark plug in it, changed the oil, and put fresh gas in it (I made sure to buy the Toro 5w30 oil and buy the correct spark plug, along with setting the gap according to the manual specifications). When I fire it up, it will idle fine if I put the choke around 50% or slightly more...give or take. However, whenever I close the choke completely and run it full throttle, the engine won't stop surging like in this video

This isn't my video, but a pretty accurate representation of what's happening.

Is this normal for a Toro Snowmaster? It seems to go away (a little but not fully) under a full snow load but it just seems like it shouldn't be doing this. I don't recall hearing other people's gas snowblowers running like this as "normal".

Anyone else out there with this or a similar model that could shed some light on what is and is not normal for this model? I'm not an engine guy by any stretch of the imagination. If the hard drive in your desktop computer dies, I'm your guy. But small engines? I wouldn't know the first thing to troubleshoot.
 
#2 ·
Welcome to the forum! Has the machine had any gas sitting in it since you bought it? Even just enough to start it? Did you buy it in October 2017, or October 2018?

Surging is a common symptom when gas degrades while sitting in the carburetor, and starts to plug it up. The degraded gas begins closing off the tiny passages in the carb, and you start surging when you turn the choke off. Or you might even stall.

You could try adding some fuel system cleaner to the gas, and running it for a while. If you're lucky, the cleaner might be able to get the little passages open again. People here have different preferences for fuel system cleaner. Star-Tron is one that gets mentioned, I think Lucas Oil makes one. You may hear Seafoam suggested, but that one has never worked for me, for cleaning a dirty carb via running it.
Gas with ethanol (most gas, at least around here) degrades pretty quickly, some people say it starts going bad in a month. I add fuel stabilizer to all my gas (I use Sta-Bil brand) when I fill my gas can. I've been fortunate enough to avoid carb issues, when using stabilizer. It's cheap insurance, and can help avoid problems.
 
#6 ·
Well whatever it’s called. I flip the choke to the left to start it (per the manual) and then move the choke lever to the right after it warms up.

Also, I just figured that since it’s an expensive and nice snowblower, I should keep the oil and spark plug fresh every winter. Can’t hurt right?
 
#4 ·
I would clean the main jet with a bristle from a wire brush pushed into a wood match...........sounds clogged....


I found a nice craftsman.Husqvarna clone self propelled Mower a guy had a sign on down the road from me.....I started it and would just surge over and over......i cleaned the main jet.......Ran like a top....


But in that video it is surging... he plays with the idle and it stops so not sure,.....but still give it a try. As R. O. said if gas sits in it over the year and can mess the carb.


I use Star tron to spec. and it seems to do well also as mentioned by R.O. also.
 
#7 ·
Yeah so small engine repair isn’t exactly something that’s currently in my wheelhouse. Approximately how difficult would it be for someone to “clean the main jet”? Also, what do you mean by “the main jet”?
 
#8 ·
The carburetor needs to be taken off, disassembled, and cleaned. The main jet is in the middle, on the bottom, underneath the fuel bowl.

Try running Seafoam, carb cleaner, in the gas, for 30 minutes. Follow directions for how much.
 
#11 ·
Cleaning a carb is very doable. But there are fewer opportunities for things to go wrong when you're just using fuel system cleaner.

I'd start with adding cleaner to the fresh gas, and running it for a while. Maybe you'll get lucky, and it will improve. If not, you'll need to disassemble and clean the carb.

I'd add partial choke as needed for now, to make it run smoothly. When you can use it in snow, you can also experiment with the choke, to see if one setting helps it make more power.

At the end of the season, either run the fuel tank dry, and/or use gas with fuel stabilizer. I keep stabilizer in my small-engine gas all the time, even in the middle of the season. It's easy, it's cheap insurance, and it can help avoid these kinds of problems, which are more hassle.
 
#12 · (Edited)
Snowman if you look at your carb usually there is a gold bolt on the bottom in the dead middle of your carb bowl that holds your carb bowl on at bottom of carb.....That is your main/fixed jet.

Hopefully your gas tank is empty and engine is cool when doing this and you have run the engine until it stops out of gas.
You can unscrew it(1/2 inch jet/bolt I believe) and pull it out. Make sure fuel line is off first if you have a fuel valve(on/off) as well. Have a clean can or disposable pie plate to catch gas that might come out hole on bottom of bowl of carb. Even if tank is empty some left over fuel in line might come out for a couple of seconds don't worry.

Usually the bowl stays up but just in case make a visible mark(straight line or dots) with sharpie or white out(rubs off easy) from just above bowl on carb. and down on to bowl so if bowl should come off by accident you have an alignment mark. Unscrew the bolt/jet...you will see visible holes that go across from each other on shaft of bolt/jet run the wire through those holes and then look for a very small hole below the two larger holes away from head of bolt/jet at bottom of threads...if clogged you might not notice it.....that is usually the culprit.....push wire through there. Once you do that run some carb cleaner through cleaned holes(3 usually) and then up middle of jet(4th hole).....Then screw it back in bowl which hopefully has stayed on carb. Make sure black washer is still on gold bolt/jet and between bowl when you put back on...washer feels like black paper. Hopefully that helps...worth a shot before you rebuild a one yr old carb. Fill toro back up with gas and hopefully no more surge. If still surging then maybe a rebuild if trying what others have said does not work first as well. GOOD LUCK!

On a wrench scale to five this is a one or two wrench project...you can do without much difficulty.....AGAIN try to empty tank first by running dry if you can or siphon back into a clean gas can....Then run dry. Then do the Main jet procedure.

Essentially you should unscrew a bolt...clean it....and put it back in. Tighten but do not over tighten.

If Bowl comes off for any reason make sure black gasket(rubber ring) is either still on carb. or in bowl you will see on carb where gasket goes. Remember your alignment marks. Most likely Bowl will stay on. You can even hold bowl while unscrewing jet so it does stay on. Not sure how tight bowl on to carb is these days on newer machines. Again good luck.
 
#13 ·
your motor is running too lean, the motor wants/needs more gas but carb cant feed it fast enough or you might have an air intake leak.
adjust mixture screws if equipped.

depending on why carb is not performing sometimes just spraying cleaner internally or using products like seafoam might "fix" the problem. if not then a further detailed cleaning is required.

mainjet removal, float and needle valve removal, mixture screws removal, if any, cleaning of said items and using a cleaner into every orfice, holes carb has and using a thin wire to make sure orfices are clear of debris and using compressed air into all orfices. using a ultrasonic cleaner to further clean also helps.

if u have an air intake leak using brake/carb cleaner or propane can reveal itself if using these around the intake pipe and gaskets to see if rpms change as motor is running.

how far you are willing to take it apart and clean the carb will determine how well the carb will perform. or just buy a new oem, aftermarket or clone carb.


 
#14 ·
Yes main jet screws out after taking bowl off. Using a small narrow screwdriver. Your carb probably also has another jet underneath a black in color plastic screw which adjust running idle. The head of screw holds down another small idle jet. Remove screw then you will be able to pull jet out. It’s about half inch long hole on side and another very tiny hole at the end. This end has a small flat round oring which helps seat it in. The tiny hole usually gets blocked. You mine as well clean everything while you have it out. I check and clean all the carburetors on machines I work on. Sometimes it doesn’t matter if they run the gas out. It’s best to run a premium gas and stabilizer through the machine at end of season. There’s also a drain screw next to bowl bolt.