Semi OT: What is the "jet" of a leaf blower and how do I adjust it?

[Stevorino]

I have a Ryobi Backpack Blower-- it starts perfectly but when I pull the throttle and give it some gas, it will slowly die as if the engine isn't getting enough of something.

I've only used it once before, and that one time I got it to run a while, but it never got up to a full throttle per say. I read somewhere that if you "turn the jet a quarter turn" it would fix it-- what is a jet where do you think it'd be located?

 

[albannach]

Sounds like the engine isn't getting enough air and is bogging down with a rich fuel mixture. If the jet is where the air and fuel mix then it might help; I'd check and clean any air intakes and filters before and see if that clears it up.

 

[Stevorino]

What is 'the jet'?

 

[XXguy]

the needle screw ...... if it's a 2 stroke engine *( you mix the gas & oil) then there are likely 2 screws near the carb..... one is your idle mix- the other is your high speed mixture.

Generally - if it was running OK before, there would be no need to adjust the needle screws. I'd also tell you to look elsewhere..... fuel line kinked... clogged air filter..... bad fuel...... etc.

 

[MSUConrad]

Dump your fuel and get new. That's usually fixes most people's problems.

 

[albannach]

The jet is where the carburetor sprays/dumps the fuel air mixture into the cylinder.

 

[k1v1116]

the carburetor will have a choke knob on it make sure the choke is on while you get the engine warmed up (you wont be able to give it full throttle during this time) then turn it off to run it normally.
the choke increases the fuel to air ratio to allow for cold starts/weather.

afaik a jet is part of the carburetor where the fuel flow is restricted and the fuel atomized to mix with the air, on a cheap 2 stroke which a backpack blower should be, the jet cannot be turned or removed.

 

[Stevorino]

There are two threaded knobs that look like the threaded end of a screw -- both have a little slit in it...are these them?

How would I adjust them? They definitely aren't typical screw ends...

 

[Stevorino]

the carburetor will have a choke knob on it make sure the choke is on while you get the engine warmed up (you wont be able to give it full throttle during this time) then turn it off to run it normally.
the choke increases the fuel to air ratio to allow for cold starts/weather.

afaik a jet is part of the carburetor where the fuel flow is restricted and the fuel atomized to mix with the air, on a cheap 2 stroke which a backpack blower should be, the jet cannot be turned or removed.

Yeah, I've been playing with the choke-- starting on full choke/then half/then no choke. When I move it to No Choke, it almost always dies within 10 seconds. It can run on half choke all day long. That's what I had to do the first time I used it.

 

[Stevorino]

I dumped the gas and put a gasoline heavy mix in it -- it ran a lot smoother and longer but still died...it still sounds like it's not getting up to full throttle. If I let it idle at all, it dies.

 

[mattmcl]

You likely have a clogged jet. Did you figure out which one is the jet? One is likely your idle mix adjuster, which you don't want to start messing with yet. Worse case, tighten one all the way down- but count how many turns it takes. Then take that one out- if it's the jet, it will have a pointy end with a tiny hole (or holes) in it. If it's not the jet, put it back in all the way, then back out x number of turns to get it back to where it was. Then try the other one.

Once you figure which one is the jet, blast it out really good with carb cleaner and put it back.

90% of the time, the problem you describe is a clogged jet. It's a tiny little hole, and cheap 2-stroke oil will clog it easily. To prevent it, you can get synthetic 2-stroke at a scooter shop, which runs MUCH better. (A neighbor GAVE me a snowblower because it didn't run- all I did was blast out the jet and put in synthetic- now it starts on the first pull).

Also, don't leave gas in it for long periods of time. Even 30 days is long enough for it to go stale, which makes starting harder.

If you are still having problems, pull the spark plug and post a close up pic if you can. It should be a chocolate brown color. If it's black and oily, the engine isn't getting enough air. If it's tan, it's not getting enough oil/gas.

 

[Stevorino]

Ok guys-- here's a pic of the only place I can see to adjust anything.

I've already screwed the phillips-head screw seen in the first pic all the way in and out, it doesn't go into anything -- i believe it only controls how much gas the idle setting gets.

From what I've been told, it sounds like the jets are the two knobs that are seen in the second pic.

Thanks guys!

 

[Jared311]

Damn... I was expecting to read how you used a leaf blower in your setup.

 

[beerocd]

I thought it was only Semi-OT cuz he was going to use it as a hop dryer.

Anyway - building on the clogged/dirty carb theory... go to NAPA autoparts and buy some SEAFOAM. Toss that in your gas mix; may take more than a tank of gas but that oughta make it run better for you. I use it in all my 2cycle and motorcycle and cars - so it's cheap, safe advice.

-OCD

 

[mattmcl]

Those two screws could very well be the jets. Generally smaller engines only have one, but I suppose it's possible.

 

[Stevorino]

Those two screws could very well be the jets. Generally smaller engines only have one, but I suppose it's possible.

If that's the general area that they'd be near...then I think that has to be them-- there's nothing else that looks remotely adjustable.

Any idea on what I use to twist those suckers?

 

[runhard]

Still off-topic but here it goes. 2-strokes are notorious for having carb troubles if they set up too long without being run. At the end of the season it's best to dump all but a little of the fuel then run it at an idle until she runs dry. That leaves very little to cause clogging problems. If it were mine I'd tear into it and clean the carb from tip to toe but if you've never done anything like that it can be a little intimidating. Thanks to the EPA, manufacturers are making it more difficult for shade-tree mechanics to work on 2-strokes. They much prefer us to take them back or buy a new one. Look at the 50 hr versus 150 hr designations that are now included on Echos, Stihls, Huskies, etc. It doesn't mean that they'll only run 50 hrs or 150 hrs, etc. it means that in testing they at least meet EPA regulations for exhaust for 50 hrs or more as stated by the manufacturer then they could be outside those regulations. I don't care about that because I know my Echo or Stihl equipment will run at 3000 hrs. or more.

 

[Stevorino]

Still off-topic but here it goes. 2-strokes are notorious for having carb troubles if they set up too long without being run. At the end of the season it's best to dump all but a little of the fuel then run it at an idle until she runs dry. That leaves very little to cause clogging problems. If it were mine I'd tear into it and clean the carb from tip to toe but if you've never done anything like that it can be a little intimidating. Thanks to the EPA, manufacturers are making it more difficult for shade-tree mechanics to work on 2-strokes. They much prefer us to take them back or buy a new one. Look at the 50 hr versus 150 hr designations that are now included on Echos, Stihls, Huskies, etc. It doesn't mean that they'll only run 50 hrs or 150 hrs, etc. it means that in testing they at least meet EPA regulations for exhaust for 50 hrs or more as stated by the manufacturer then they could be outside those regulations. I don't care about that because I know my Echo or Stihl equipment will run at 3000 hrs. or more.

It just doesn't make sense that it'd run for literally 5 minutes and have carb clogging problems though. The gas has been in there for less than a month or so.

 

[mattmcl]

Well, it could make sense, but like I said before I'm surprised an engine that small has two jets.

Larger 2-strokes use two or more jets- one to start up, and one once it's up and running. I'm oversimplifying, but you get the idea. One could be clogged, but not the other.

I can't see from the photo, but aren't the tops of those bolts slotted? They may require a hex wrench or something aside from a screwdriver.

 

[beerocd]

It just doesn't make sense that it'd run for literally 5 minutes and have carb clogging problems though.

Had a motorcycle like that. The carb is clogged up, and over time the float bowl filled up via trickle effect. Worked for a few minutes then BAM engine would die from fuel starvation. Actually makes a lot of sense if you've had it happen to you before. So if you're not going to take it apart, then keep running a heavy dose of carb cleaner through there in 5 minute increments and it should get better.

-OCD

 

[rokipynes]

Buy a new spark plug!! Very important first step. Fouled plugs in two strokes can look OK but a replacement makes all the difference. Not a bad choice to have a spare around anyway. Run some carb cleaner through as mentioned and keep putting a small amount in the gas ( capful at a time ) until it cleans up. Get Stabil and put it in your gas. I always have Stabil in any gas stored for even a month, especially two stroke gas. I am sure other gas treatments are available but I have always had excellent results w/Stabil.