Thanks MM1, I'm waiting on my Stihl feeler gauge for a 4 mix I'm currently repairing. The part about the cam placement was most helpful, thank you sir.
So as I'm putting my BR550 back together because of carbon stuck in the exhaust valve seat, I'm reusing the cam gear as it shows little wear and still has the paint marks on the teeth. If I line the arrows on the cam gear up with the witness marks on the inside of case. the cam lobe is pointed up. if I align the center painted mark on the cam tooth with the pin for the followers as you suggest, the lobe is pointed down and the arrows are horizontal but no where near the witness marks in the case. OE Stihl gear. Seen this before?
You don’t have to take them apart to clean the carbon Stihl makes a decarobonizer fluid that cleans the valves and combustion chamber. BR series blowers with the 4 mix engine time with the lobe up, FS series 4 mix time with the lobe down.
Hey medic I have a question , I have a Ms 110 R , and I checked vacuum and pressure, everything in good shape . Changed the carb to a new one and the motor runs but with no power when I pull the trigger to open throttle. I changed valve gasket ,spark plug, the cam gear looks in good shape and I also readjusted the valves . You think ash can damage valves in either way . Since the piston is full of ash . I don't know tell me what you think. Thanks medic
Hey medic , you ain't going to believe what was the problem , after breaking down the engine apart to check piston bearings and all the fun cleaning all that red silicone , I put it back together and did the same thing ,turned on well but in open throttle it would boug down 👇. I was upset 😭. Dam it boy . So I said last shot , had a used magnito from an old fs91R .and I said here goes nothing and it worked well the same power like when bought new . This has never happened to me ,just wanted to share . Before doing everything I did check the magnito . Thank you mower medic for your great videos they helped me alot to break apart my FS110 R and put it back together.
Would be great if they had a polished and hardened metal cam gear. Would probably take a long time to wear it out. A cam shaft gear combo made of plastic just seems like it would wear out quickly. Anything made of Plastic inside an engine just doesn't sound like a good idea to me. Great job on the trimmer fix.
Also more fuel efficiency and less noise, generally. I love these engines for the way they feel and sound, but you do need to be willing to put in the (very slight) extra maintenance to keep it in top shape. It's NOT hard to take off 4 screws and adjust the valves every once in a great while..
I just did my valve adjustment for the first time triple checked it and went to start it and it won't run right reset the carb to factory still run right I bet this is my problem but I'm hoping a good car cleaner fix the issue and not a cam gear
MM1 the little arrow on the flywheel when adjusting the valves has to be at top dead center, I know that,but you might have to rotate the flywheel again,it could be on exhaust stroke,does that apply when changing the cam gear.Sorry for the long post.Great video.
You can rotate the engine 1 time or 50million times as long as the arrow is pointing to the screw you’re good to go. The orientation of the arrow on the fly wheel stays the same, every time that arrow comes around the engine is it top dead center with the cam out. Put the camshaft in you would have two possible scenarios top dead center on the compression stroke or top dead center on the exhaust stroke Which would be easy to tell because the valve would be open
A wile back i came across a antique sthil 051 av electronic it was manufacturer in 1972 it did not run at all I had to apply my Magic Touch get it going got it going until the fuel line busted I was like oh man so I put it on the back burner for now got way too many lawn mower to work on this thing has a cast magnesium body you don't see those anymore
The problem is the "dead end" style lubrication Stihl employed on the 4-MIX. On Shindaiwas all of the mixture passes the cam, cooling and lubricating it. Stihl only bypasses a bit of the charge for lubrication purposes.
May be the gear is in plastic because if metal, the worn out metal from the friction can go back in the crankcase and ruin the bearings, piston and cylinder. I was checking the back little metal cover and the top hole is wider than the other 3 holes. I'll order a new cover and check if it has the same tolerance.
@@THEMOWERMEDIC1 my cam was fine. Turned out my tank vent was bad. Your videos have refreshed my memory back when I got stihl certified a long time ago. Should be able to keep it running like a top now
Tell ya what.... I work on a lot of equipment everyday and I must say MM1 is bad a** !! To anyone who reads this, pay close attention to this man!!! Jeremy is a TRUE Expert Mechanic!!! Subscribe to Mower Medic 1 ! Jeremy Thank you, I have not done a cam on one of those... Always learning something new everyday.
The problem I'm having with those four mixes is not the camshaft wearing out but the axles for the cam and the cam followers wear out the engine case and the cover case and when this happens you might as well junk the engine because the Parts which include the whole cylinder barrel and piston and cover are worth as much as a whole unit
Good video. But what causes this ? I vote the for the worthlessness of plastic for cam material, especially where you have the speeds involved and one lobe suffering the friction of two lifters while doing double duty, (i.e. having to opening both the intake and exhaust valve). Pretty slick design, but an atrocious material choice.
@@victorrippe5845 amen, we have a whole fleet of 4mix trimmers n blowers where I'm employed and I'm always fixing something. JUNK, awesome idea in Theory but anything other than an edger or polesaw their junk otherwise.
@@jdclay1547 Yes man I totally agree Stihl went downhill with those 4mix junk I threw away thousands of dollars on them till I just gave up on them Echos little srm225 I garentee you will outlast any Stihl 4mix and it’s only a $219 trimmer it’s incredible I bought one of those little 225 4years ago man we have beat the living crap out of it and different employees use it and the thing still runs like a little champ I really under estimated those little units and man they sure hold up commercial work really well I never went below a 266 or a 2620 but hell it’s hold up with my big trimmers
That cam is the stupidest material possible for a rubbing part, I bet they want a fortune for it . Ido not use mine often but certainly do not want to buy another cam.😮
Mower Medic 1 - you are a genius. Thanks, David.
Amazing that it ran with so much wear on the old lobe. As always a fantastic video. Thanks for sharing
Well done Sir!! Detail oriented for a quality job. Explained very well and to the point. Appreciate your time and effort, always...🙂
You definitely know your small engines keep up the good work god bless
Thanks MM1, I'm waiting on my Stihl feeler gauge for a 4 mix I'm currently repairing. The part about the cam placement was most helpful, thank you sir.
Believe it or not a Coke can is the right dimension that's what I used.
@@pureblood324 you are correct, I’ve found that out since my earlier comment. Thanks bud 👍🏼
This Video of yours is an excellent one,👍.
Great video!!!!
What is the assembly lubricant that you are using on the cam gear? Can two-stroke oil be substituted for it? Thanks
Dose it have to be on the compression stroke when you put it on top dead center
Thx mower medic we love ya
Cleaning old sillycone is always fun. I tore apart a Honda one time , i swear they let a 5 year old put it on😳
Great vid
Good job 👍
Does Stihl make a special oil for 4 mix ??
Good jób like always
So as I'm putting my BR550 back together because of carbon stuck in the exhaust valve seat, I'm reusing the cam gear as it shows little wear and still has the paint marks on the teeth. If I line the arrows on the cam gear up with the witness marks on the inside of case. the cam lobe is pointed up. if I align the center painted mark on the cam tooth with the pin for the followers as you suggest, the lobe is pointed down and the arrows are horizontal but no where near the witness marks in the case. OE Stihl gear. Seen this before?
You don’t have to take them apart to clean the carbon Stihl makes a decarobonizer fluid that cleans the valves and combustion chamber. BR series blowers with the 4 mix engine time with the lobe up, FS series 4 mix time with the lobe down.
How long does the plastic cam gear last if burning 30 tanks of gas/year and cutting heavy weeds?
Good job.
Would hear from using it for hours on end cause this ?
Hey medic I have a question , I have a Ms 110 R , and I checked vacuum and pressure, everything in good shape . Changed the carb to a new one and the motor runs but with no power when I pull the trigger to open throttle. I changed valve gasket ,spark plug, the cam gear looks in good shape and I also readjusted the valves . You think ash can damage valves in either way . Since the piston is full of ash . I don't know tell me what you think. Thanks medic
Take a picture of the camshaft and all of the internals of the engine and email them to me at themowermedic1@gmail.com
Hey medic , you ain't going to believe what was the problem , after breaking down the engine apart to check piston bearings and all the fun cleaning all that red silicone , I put it back together and did the same thing ,turned on well but in open throttle it would boug down 👇. I was upset 😭. Dam it boy . So I said last shot , had a used magnito from an old fs91R .and I said here goes nothing and it worked well the same power like when bought new . This has never happened to me ,just wanted to share . Before doing everything I did check the magnito . Thank you mower medic for your great videos they helped me alot to break apart my FS110 R and put it back together.
Isn’t there two top dead centres ,I looked at Steve’s small engines video ,just a point I noticed mate ,jimmy Australia
Would be great if they had a polished and hardened metal cam gear. Would probably take a long time to wear it out. A cam shaft gear combo made of plastic just seems like it would wear out quickly. Anything made of Plastic inside an engine just doesn't sound like a good idea to me. Great job on the trimmer fix.
Yes it appears stihl quality isn’t there
@@LivingInFloridaPanhandle I mean great engine just needs a metal cam gear and would be perfect. A small turbo would be badass.
What is the piston position before we do this? How we do that?
Pitston is up
The piston up or down When you installed the cam GEAR ? Thank you
Up. TDC
What is the feeler gauge size for the valve clearance
.004
.004
Are there any benefits to these 4 mix engines it seems like there’s just more to go wrong I like my 2 strokes.
Benefits are more power, less vibration less operator fatigue
Also more fuel efficiency and less noise, generally. I love these engines for the way they feel and sound, but you do need to be willing to put in the (very slight) extra maintenance to keep it in top shape. It's NOT hard to take off 4 screws and adjust the valves every once in a great while..
I just did my valve adjustment for the first time triple checked it and went to start it and it won't run right reset the carb to factory still run right I bet this is my problem but I'm hoping a good car cleaner fix the issue and not a cam gear
Did you make sure the engine was at TDC on the compression stroke and not on the exhaust stroke ? What gap did you set them at ?
MM1 the little arrow on the flywheel when adjusting the valves has to be at top dead center, I know that,but you might have to rotate the flywheel again,it could be on exhaust stroke,does that apply when changing the cam gear.Sorry for the long post.Great video.
You can rotate the engine 1 time or 50million times as long as the arrow is pointing to the screw you’re good to go. The orientation of the arrow on the fly wheel stays the same, every time that arrow comes around the engine is it top dead center with the cam out. Put the camshaft in you would have two possible scenarios top dead center on the compression stroke or top dead center on the exhaust stroke Which would be easy to tell because the valve would be open
Thank you very much,MM1
What do you charge 4 a cam shaft job on a sthil 4mix
I have no idea I work for a nonprofit organization
A wile back i came across a antique sthil 051 av electronic it was manufacturer in 1972 it did not run at all I had to apply my Magic Touch get it going got it going until the fuel line busted I was like oh man so I put it on the back burner for now got way too many lawn mower to work on this thing has a cast magnesium body you don't see those anymore
The problem is the "dead end" style lubrication Stihl employed on the 4-MIX. On Shindaiwas all of the mixture passes the cam, cooling and lubricating it. Stihl only bypasses a bit of the charge for lubrication purposes.
😂good theory but your way off
@@THEMOWERMEDIC1 Feel free to correct me 🙂
You started with the cover off!
How the hell do I get in there to begin with!
May be the gear is in plastic because if metal, the worn out metal from the friction can go back in the crankcase and ruin the bearings, piston and cylinder. I was checking the back little metal cover and the top hole is wider than the other 3 holes. I'll order a new cover and check if it has the same tolerance.
It's plastic because it saves weight and is cheap to make.
I can’t believe they put a plastic gear in it. I bet I need to do that job on my 91
I guarantee u do
@@THEMOWERMEDIC1 my cam was fine. Turned out my tank vent was bad. Your videos have refreshed my memory back when I got stihl certified a long time ago. Should be able to keep it running like a top now
Tell ya what.... I work on a lot of equipment everyday and I must say MM1 is bad a** !! To anyone who reads this, pay close attention to this man!!! Jeremy is a TRUE Expert Mechanic!!! Subscribe to Mower Medic 1 ! Jeremy Thank you, I have not done a cam on one of those... Always learning something new everyday.
The problem I'm having with those four mixes is not the camshaft wearing out but the axles for the cam and the cam followers wear out the engine case and the cover case and when this happens you might as well junk the engine because the Parts which include the whole cylinder barrel and piston and cover are worth as much as a whole unit
Good video. But what causes this ? I vote the for the worthlessness of plastic for cam material, especially where you have the speeds involved and one lobe suffering the friction of two lifters while doing double duty, (i.e. having to opening both the intake and exhaust valve). Pretty slick design, but an atrocious material choice.
Heat, “string too long” lugging the engine.
I’d say heat and thermal breakdown. Those things run super lean! Thanks EPA!
This is the reason i prefer echos
@@victorrippe5845 amen, we have a whole fleet of 4mix trimmers n blowers where I'm employed and I'm always fixing something. JUNK, awesome idea in Theory but anything other than an edger or polesaw their junk otherwise.
@@jdclay1547 Yes man I totally agree Stihl went downhill with those 4mix junk I threw away thousands of dollars on them till I just gave up on them Echos little srm225 I garentee you will outlast any Stihl 4mix and it’s only a $219 trimmer it’s incredible I bought one of those little 225 4years ago man we have beat the living crap out of it and different employees use it and the thing still runs like a little champ I really under estimated those little units and man they sure hold up commercial work really well I never went below a 266 or a 2620 but hell it’s hold up with my big trimmers
Rev that thing!!!
You changed the orientation of where the pushrod sits
I did no such thing
@@THEMOWERMEDIC1yes you did go back to the video 6.10 then watch to 6.20sec you clearly see you made a mistake and switched them over , go look
Why that gear is not made from metal? 🤔 Why plastic?
Gringo como tiene que estar el pistón arriba o abajo responde
I explained it in the video you must’ve skipped over that part
Yea..its odd how it only wore off the crown..not the teeth ..??
Why dosnt stihl make the cam gear out of metal ,is it about making money from spare parts old jimmy Aust
Could you add at to yours videos where you can get the parts,please i like a lot the videos, thanks for sharing your knowledge
Any lawnmower shop near you is where you’d get parts
The main problem is plastic!
People ever clean their s***
Junk, honda did that plastic cam with there little generator motors to .
That cam is the stupidest material possible for a rubbing part, I bet they want a fortune for it . Ido not use mine often but certainly do not want to buy another cam.😮
4mix engines are junk 2 cycle's are lighter , sound better and have just as much power with a smaller displacment
I agree till you said 2 strokes have more power.