Removing a Weed Eater Engine and Running on a Stand - 4 Stroke

Makita Impact Driver Used: amzn.to/2vUrcKc
In this video, we are pulling the engine from a Ryobi S430 30cc four stroke string trimmer/weed whacker. This engine has a steel overhead cam and is functionally very similar to a car engine except that it is a whole lot smaller. To tear everything apart quickly on the weed whacker, I am using a Makita SDT131 18V LXT Lithium Ion cordless impact driver. Once the engine was removed from the trimmer, I mounted it with custom engine mounts to a 2 x 6 piece of lumber and started the engine up. To show how the valvetrain works, I removed the valve cover while the engine was running. This is a DIY project that is pretty simples and will demonstrate how a four stroke engine works.

[@HoliTalksAboutStuff]

Never thought i'd see a weed wacker engine with an overhead cam, the more you know.

[@CoolStuffGuysLike]

I know, it's crazy. I bet we will start seeing fuel injection in a few higher end chainsaws and weed eaters in the next ten years.

[@HoliTalksAboutStuff]

@@CoolStuffGuysLike the new stihl ms500i saw has fuel injection, from what I hear it guzzles through fuel, which I guess Is to be expected.. that saw goes for atleast 1500-1700, so. It might be abit until we get fuel injection in the homeowner line. Nice video by the way!

[@fromthebackofmymind]

@@CoolStuffGuysLike Catalytic convertors and 02 sensors too. EPA and C.A.R.B. laws will eventually stop 2 strokes sales. Power equipment is constrained in Cali. Primer bulb mowers with fixed throttle and no spill gas containers, came out of their regs.

[@robwilcox9296]

This model worked great for me, then refused to run without the choke. Discovered the rocker bolt for intake/exhaust had come loose, wrenched it down again and it has run great since.

[@markworden9169]

Nice little overhead cam , the other 4 cycle weedwacker I've seen were pushrod, this engine oils top end very well.

[@vaporistic4203]

Awesome video! This engine would be cool to power a rc car if the wacker itself breaks too lol. I find that the belt likes to pop off the camshaft pulley. Good thing these engines are non interference!

[@CoolStuffGuysLike]

Thank you! I agree it would be a cool RC engine. It doesn't have the high whizz like a two stroke or nitro two stroke. Probably doesn't really have any real power advantage but it would sound cool and should have plenty of go juice.

[@vaporistic4203]

@@CoolStuffGuysLike you're welcome and I agree with you on that.

[@fromthebackofmymind]

Yup, very cool. Some experimentation to limit WOT so the belt does not pop off. My 2 stroke poulans run well @7000rpm Since this Ryobi is a 4 stroke perhaps max should be < 6000rpm? Might be just adding a magnet for a hall sensor and tachometer To test run. And adjust end point on servo.

[@fromthebackofmymind]

Much better than the Toyan fake 4 stroke. A four cylinder two stroke. No flywheel/ magneto ignition system. It has glow plugs. Not everyone online just fell off the turnip truck. This Ryobi checks many boxes. Thank you.

[@phyuku650]

AWESOME video and very informative

[@MotorizedMayhem48472]

im puting a weed wacker engine on a old Electric scooter i got at a garage sale for free and i thought it would be a good thing to fully know how they work, but i have a two stroke engine and it was cool anyway!

[@PearComputingDevices]

This is a neat little engine. Just always store it upright or it will get oil in to the cylinder and lock up. Forcing the owner to remove the tapet cover and open the exhaust valve.

[@CoolStuffGuysLike]

Thanks! Yeah it is a pretty cool little engine with the overhead cam and being so tiny. Doesn't have a lot of power but cool to play around with. I need to think up a new use for it now.

[@Connorsdaddy12062008]

Why wouldn't you just remove the spark plug to release the oil in the cylinder?

[@PearComputingDevices]

@Connorsdaddy12062008 Because it's not actually something you can fix that way. The valve basically jams up and thows timing. It's a belt driven overhead cam. You could in theory I guess try it. But it didn't work for me.

[@topnotchcontent]

Thanks for the video!

[@ReVoLTedShadow.]

Keep it up bro! I enjoy the videos 😎

[@overseerofyahweh7811]

I do love all engines, don't know why. I got a gx25 Honda, different OHC setup, strange to say the least. It use a (best way to say it) a butterfly on a shaft camshaft.

[@jamieshorter7093]

Cool.....My first time ever seening this.....Good job

[@putraadriansyah8082]

Add a small car alternator to it to get 12v and a bit Arduino with some code to regulate throttle based on load

[@user-nk2zj6xy7d]

nice video very straightforward and to the point....

[@MrThunderCunt]

Im thinking about using one of these in a full suspension mountain bike. Gon a try to make some more power with it though with a better carburetor amd exhaust, maybe clean the ports a little to

[@philldownes8685]

The exhaust on these little engines is what is realy killing them. put a manifold and simple exhaust and they pick up so much more power and not getting strangled.. good motor.

[@CoolStuffGuysLike]

That is good to know! Thanks for the info.

[@jllanesphoto]

Great video.

[@thisissoeasy]

Excellent video! Good explanations and good quality film work. Thanks for sharing.

[@elroygrey2899]

Can’t help but want to hear 4:20 as my phone alarm

[@tsuzukimurphy64]

i thought he made a mistake saying overhead cam but damn i was wrong I've never seen an engine that small with an ohc

[@mikeduwe]

no nut holding the flywheel on while running!

[@fromthebackofmymind]

There a 2 types of reduction drives. Sold on abay or azon. The smaller reduction drive is internally a worm gear setup. So it will only rotate in one direction I believe. The larger reduction drive is simple sprocket chain setup. So it can run either direction. Unless you have the bike bury setup with a one way bearing on the input sprocket. Reduction will vary. 5:1 or 3:1 numerically Since this Ryobi 4 stroke and a relatively short crankshaft, I would try to use one of the two Gear reducers with it's factory centrifugal clutch. So you will need to source a clutch bell that will fit the ryobi and the gear reduction will have to spin counter clockwise, to make a functioning clutch. The engine bracket he built is very good. A sheet of aluminum or steel can be shaped and formed to still use air cooling from the flywheel. And as others said, maybe different exhaust system . VERY IMPORTANT! Any diy exhaust pipe MUST have a spark arrestor. Or you may have a very bad day in dry grass.

[@MrKing10123]

Hi love the video and wish I had found it sooner. Would it be possible to get more in contact with you to get a rundown of the oiling system from the tubes, check valves, and air/oil filter? I am currently an engineering student and my team is working with this engine and we have been making some assumptions as there is limited information on this engine.

[@CoolStuffGuysLike]

Thanks man. I am no expert on the little ryobi engine so I probably couldn't help a hole lot. The air filter is just a foam element if I remember right. I don't think it has an oil filter but I would have to go check. Most small four strokes like this don't. The oiling system is just using crankcase pressure and a little port. I was going to run the little weed eater engine on methanol which I may do once the weather warms up a bit.

[@Farmtractor]

I have a similar engine only 2 stroke. How do I mount it? Or at least mount it upright how you have it. Thanks!

[@CoolStuffGuysLike]

I used a couple pieces of angle iron to build a bracket that mounts to a few of the bolt holes on the crank case.

[@gregfriehauf4930]

Great video, learned a lot, thanks.

[@bjchapman1709]

Where can I get the custom bench bracket? Or did you build it? Are they available for other weed eater motor designs or from other manufactures? Thanks

[@anthonym9007]

How does the oil system work, is there a pump that is connected to the engine somewhere? I saw it squirting oil when you pulled the valve cover off, what creates that pressure, and where else is the oil supplied to.

[@goldstandard7406]

am I seeing correctly, when the hole in the camshaft gear is at 6 o'clock, the center of the magneto on the flywheel is lined up center with the ignition coil? Im trying to verify the timing. Can you tell me where the hole in the camshaft is when the coil and magneto are aligned? I have a Black Max 4 cycle trimmer. It has never run. got it on clearance and cant return it. I have spark, i got a new plug, will not run with starter fluid in the carb. Will not do anything. from what I understand disassembly is required to find timing mark on the crank shaft. I get a little, very little smoke from exhaust. Any help would be appreciated. I have resistance when pulling the cord and the spark plug is in, feels like compression.

[@111000100101001]

I see it has a little compression release pin that sticks into the exhaust lobe to slightly bump open the exhaust valve to lower cranking compression:)

[@radiated-one]

Who makes the engine? Is it Honda or subaru? I know of the Honda 25-35cc mini engines,and Subaru Robinson make a small similar engine.Is it a Ryobi factory Chinese knock off? Very curious.

[@YODAMAN5]

GREAT INFO, KEEP UP THE GOOD WORK.

[@CoolStuffGuysLike]

Thanks, man! That is a cool little engine. I have a little generator from the 1950s I'll be working on next.

[@fromthebackofmymind]

My Flysky has a 3rd channel. Add a 5v relay for kill switch.

[@goldstandard7406]

hello, I have one of these that will not run. it was new when I got it. Clearance, cant return. I have spark, gas, air, I have checked timing several times. I get a bit of smoke when spraying starting fluid. has never cranked up, not even a rev. any suggestions I can check please?

[@ToyManFlyer1100]

Can you run this upside down?? Would like to put on a R/C plane....

[@CoolStuffGuysLike]

Since it is a standard wet sump 4 stroke it will not be able to run upside down without most likely blowing up in a big smoke show. It is a cool little engine though. Might be a little heavy for an RC plane.

[@carpediem19999]

good video!

[@CoolStuffGuysLike]

Thank you. It is a pretty cool little engine!

[@amend5269]

How could one reduce the idle to 60 rpm?

[@AMDcore1]

Did anyone else notice that extra little lobe 180 degrees opposite on the exhaust cam right after the intake stroke lobe makes its pass? Im guessing it might be used for exhaust gas scavenging or some kind of way to pull in a little bit of un bured fuel from exaust fumes using intake vacuum? Might be an emissions thing.

[@matiaslarrain5618]

Or for lubrication purpose

[@conner5611]

Thats the compression release it springs closed when run you need this for easier starting

[@anthonyamanda1163]

Can I put this on a bike?

[@hiseminencetheholymacdiarmada]

Couple it with a truck alternator and inverter and make a generator

[@aydensexton1501]

Great video I think I might have a sthil weed eater lying around that I don’t use I’m thinking of making an rc car I’m pretty sure the motor is 42cc and a 2 stroke what do you think? 🤔

[@CoolStuffGuysLike]

Seems like a cool project! Sometimes the newer chainsaws will have the bottom half of the crank case molded right into the housing which might be a little tricky if that is the case.

[@aydensexton1501]

Cool Stuff Guys Like yeah but like I’m gonna use an old weed wacker not a chainsaw I have no way to connect the relay boards an steering module

[@giltorres5310]

Did you ever used it in anything ?!!!!!

[@draganapalackovic2649]

My flywheel is stuck. I cannot rotate it. I have a CMI trimmer. Any ideas?

[@CoolStuffGuysLike]

Hmmm, that seems like the engine is probably seized, like you broke a piston or it was outside and rusted in place. You could pour some oil in the spark plug hole and let it soak for a couple days but it probably won't free it up. You can try penetrating oil also but it is hard on rubber seals, so I don't like to.

[@draganapalackovic2649]

@@CoolStuffGuysLike Thank you. It did not stay outside. It was difficult to start so when l pulled the rope hard it got stuck. At first l thought it might have been the rope, i.e.coil,but it worked fine when disassembled from the flywheel. Flywheel is stuck. I see the nut but it is difficult to reach because of the propellers of the flywheel. I can see the bottom of the engine from the back, when l remove the tank, should l put some oil down there as well?

[@draganapalackovic2649]

@@CoolStuffGuysLike l pute some oil in the spark plug hole and after a few hours l was able to spin the flywheel a bit but not much. Should l wait a bit longer or try to open the cylinder?

[@CoolStuffGuysLike]

That is promising. I would work it back and forth a bit. It should hopefully free up enough. If you can't free it up, you will need to take the head and cylinder off. If it is a 2 stroke it is very simple. If it is a 4 stroke, just make sure to mark the timing belt and pulleys so that you can get it back together on the same teeth.

[@annieniemand7494]

WoW!

[@orionthehunter9107]

I have the same Ryobi trimmer. It starts fine but after it's warmed up it starts slowing down. Even after I squeeze the throttle it eventually stops. It will not start until it has cooled. Then it will start again but only run for about 2-3 minutes and shut down. Not burning oil. What could be wrong?

[@conner5611]

Valves might need adjusted or possibly a carb issues

[@orionthehunter9107]

@@conner5611 nevermind. The motor locked up. I'm tired of dealing with it. I bought myself a Stihl Combo set. It's the best.

[@conner5611]

@@orionthehunter9107 nice i love sthil they are reliable and easy to work on

[@orionthehunter9107]

@@conner5611 I totally agree. I had heard that the 4 stroke, or whatever they call it, had it problems but the Ryobi sucks.

[@redblue40rc33]

Be perfect for rc plane

[@CoolStuffGuysLike]

Yep! Might be a little heavy for an RC airplane but it probably would work good for some homemade rc car.

[@MotorizedMayhem48472]

never seen an overhead cam on a weed wacker tho

[@richardpope3536]

How's it go again? Reahhhh... Lol

[@nathanstoltzfus4593]

But could I put it on a mower...?

[@tracebrown9341]

Your can mount that to a bike

[@spra8u]

There goes your 70ml of oil

[@benjaminleslie3155]

It's a very cheap engine from what I've heard. All kinds of different problems come up with that trimmer.

[@slow_r3188]

Bro no way it’s got ohc

[@TheHomeWinemakingChannel]

Zoom to 6:00 and you can see the overhead cam. It is also pretty obvious that it has an OHC since it has the little timing belt and pulleys with one of the pulleys right below the valve cover.

[@grantmx4742]

These engines have a big problem, they don't last, cam bearings go out/loose, belt skips teeth and that is all she wrote. Junk engines, I have a pile of them, trash weed eaters. They burn oil like you can't believe fowling the plugs in a day. Don't keep them level, the oil hydraulic locks the piston solid. Have to take the plug out to clean it out. Real sad, because it could have been a great engine for weed eating. Long story. Check the reviews and you will know the truth.

[@justabouthadit5872]

Sigh...

[@kurtbaboolal9409]

Òòòòò

[@justabouthadit5872]

Yawn..