Fixing A Stihl Trimmer That Doesn't Always Stay Running.

i was contacted by a complete stranger the other day they said they got my number from someone they worked with and they told them that i could help them out i must say i was a bit taken back by the request but i don't mind helping so long as they weren't going to give me a hard time about the way i work on things they said they had a steel trimmer and it needed some work now i accepted the offer drove to their house and this monster trimmer is what i brought home in today's video we look at the steel trimmer and the problem is that sometimes it starts but only when it wants to i will say one thing if you need a powerful trimmer to get the job done by all means get something like this however you need to be prepared for some very unlikely maintenance that you may not know about now i'm going to try and repair this trimmer however it may not be the exact repair you need to make to yours we'll explore other options later in the video now we're only going to mention what these other options could be we don't have enough time to look into them but if you need more information on these options you're welcome to ask as many questions as you need to now the person i got this from is well aware of the many helpful videos out there so they already looked at the spark arrestor screen changed out the spark plug and even the air filter but this time those items didn't help out their issues they were having now all those are great maintenance items but i don't think they're aware of the other ones related to this trimmer the first thing i looked at was their fuel and i'm glad to say it didn't have any water in it nor was it stale now i did empty most of it out so i'm going to put some of my own fuel in it to test it now when pressing the purge bulb it was filling up with fuel but even though it's working it doesn't mean there isn't an issue with the carb next i'll try and start it and show you what it's doing so unfortunately at the moment it's not going to start and run but at least we know it has the ability to run which means we can continue with the diagnostic now it could be a carb issue but in the years this thing has been in service it's never had the valve lash inspected which is a huge maintenance issue with this particular engine now the valve lash is the clearance between the rocker arm and the top of the valves and this clearance is very important when it comes to the timing of when the valves open or close so we need to remove the top cover followed by the valve cover put one of the rocker arms in the down position and then check the other rocker arm to see if the valve lash is out of spec with the exhaust rocker arm in the down position i'm gonna use this sliver of a four thousandths of an inch shim to feel how it fits in the clearance between the intake rocker arm and valve after sliding it into the clearance and moving it around i don't feel any drag on it and it's really easy to move around what that's telling me is that the clearance is larger than the shim so that means it's out of tolerance and needs to be adjusted after putting the intake rocker arm down i'm going to do the same procedure for the exhaust clearance and just like the intake it's also loose and needs to be adjusted so the shim is not loose but drags between the valve and the rocker arm to make the adjustment i'm going to slide the shim around while slowly turning the nut on top of the arm until the shim lightly drags between them if you turn the nut too far the shim will get stuck in the clearance and to fix it you'll just need to turn the nut the other way until it's free again once the shim is loose again start the procedure over and this time try making smaller adjustments now once the shim is dragging between them move on to the next arm now what i mean by dragging is that the shim is not loose but instead there's some resistance when you slide the shim around now after pulling on the rope until the other rocker arm is in the down position i'll do the same procedure on the intake rocker arm after turning the nut a few degrees i can feel the shim drag between the arm and the valve so we should be good to put everything back together and try another test start i really wish i had a full set of these shims because i really would like to know what the clearance was before the adjustment but getting the job done is more important than knowing [Music] so unfortunately it didn't start and this could mean we have a carb issue on top of the valve lash problem i'm going to adjust the car by turning out the l screw but before i do that i'm going to turn it clockwise until it stops to find out where it was set at that way i can put it back to where i found it so it turns out it takes a full turn to bottom out the screw so when turning it back out i'm going to turn it an additional quarter turn so it gives more fuel to the engine so as you can see it was running while on choke which it's not supposed to do but then it stops when the choke is turned off that unfortunately means we have a pretty serious card problem i didn't focus on it because it really didn't make a difference but i did make some adjustments to the carb on both the h and l screws however everything points to an internal carb issue now since it won't stay running no matter what changes we make we've got to put it on the table for a full inspection or at least enough of an inspection to decide what to do i'll be honest i don't normally work on this grade of equipment and i had forgotten how different this machine is to the normal stuff i work on now the air filter base is surprisingly made out of metal and there's also a breather tube that goes to the top of the fuel tank while trying to take it off i ended up taking the tube off the tank which works just as well although you do risk breaking the port it's connected to so i would suggest taking it off the base instead after that i'm going to disconnect the throttle cable and the fuel lines but when i was trying to figure out how the fuel lines were connected and while pressing the bulb i found out we have a very serious issue the carbon was leaking fuel especially when pressing the bulb i'm going to let you know the fuel is not supposed to be spraying into the carb like this when pressing the bulb now the main purpose of a bulb is to pull fuel from the tank and into the carb eventually returning it back to the tank doing this makes it easier to start the engine it's not supposed to spray any fuel for this type of engine it's different for lawn mowers and snow blowers which are supposed to do that so what am i going to do now well if you've seen any of my older videos you'll know that i typically go through the carb and try to fix it but this one is a bit different so what happened is i took the carb off the engine and took it apart and eventually realized that the metering diaphragm was in rough shape so i replaced it i also inspected the pumping diaphragm and it was in decent shape as well i cleaned the car but put it back onto the engine and this is what happened now i know it's hard to tell so i'm going to touch the fuel and it should be pretty obvious that it's still leaking now it's not as bad as it was before we opened it but it still doesn't matter now i have to decide if i want to find and order the correct rebuild kit or just buy a new carb instead and if you've seen my older videos i typically just order a new carb the reason i order a new car but versus getting the rebuild kit is because it's easier to find and you don't have to worry about taking the carb apart again there's also another reason why i insist on just replacing the carb and it's because it makes good financial sense the cost of the kits are getting to be just as much as the new car but so i think most people would see that choosing the carb is the best option before you replace the car but set them side by side and compare them to make sure the new one is going to work after looking at this one i'm very certain it's going to work and that is until i try to install it and that's when i run into a physical roadblock so for some reason i seem to be stuck and i can't push the carb against the engine but once i took a look around i realized that the brass port is hitting the emissions port on top of the fuel tank now i tried to work the carb around this thing and i even tried prying on it but i was really concerned that i might break it so it looks like the brass port is either too big or just too long than it's supposed to be to make it work i'm going to clearance only the part that's hitting it i know i'm going to get some criticism for it but i think it's the right thing to do especially for an aftermarket carb after sliding it back onto the studs it now clears the emissions port and once i line up the brass port with the impulse hose the carbon now sits against the engine like it's supposed to after that i just need to hook up the throttle cable the fuel lines and before i put the metal base back on i need to confirm fuel flow so when pressing the purge bulb fuel will flow up through this short fuel line and into the carb fill up the bulb and then go back to the tank through this longer fuel line as you can see fuel is flowing just like it's supposed to through the system now if your fuel is not flowing like this there could be an issue with your carb or your bulb also if the bulb doesn't fill up at least partially with fuel the engine is very unlikely to start now remember to install the emissions hose back to the port on top of the fuel tank if yours came off like mine did if you don't remember the engine could breathe in unfiltered air and cause it to wear out prematurely now once this part is done we'll start it back up and see how it runs hopefully we don't find any surprises and i can give it back to the owner [Applause] uh so yes [Music] so the good news is that the engine starts and runs really well but the bad news is that the clutch is not working like it should and the trimmer head is spinning when it's not supposed to it turns out the clutch and the rest of the engine as a matter of fact is very rusted under the cover so the clutch once engaged stays that way now i can't confirm that the clutch is stuck because if i slowly pull on the rope the trimmer head spins as well which it's not supposed to do so i had to take out the clutch and remove as much rust as i could now even though i had to do it multiple times it does work much better but i would suggest replacing the clutch in the future another reason why this trimmer would have a running issue is because fuel may have been left in the tank during winter storage which here is about four and a half months now i have heard from a lot of viewers who say they don't do this and have never had an issue but i think it's an issue of the area you live in and what type of fuel you use in my experience it's just best to drain the fuel out and run the machine until it stops in the end this trimmer is running again and hopefully they'll take better care of it i didn't ask about why i had so much rust on it because more than likely i wasn't going to get the answer i was looking for so my question is do you leave fuel in your trimmer during winter storage and if so why as much of a pain as it is draining the tank and running it until it stops i still do it before winter because i don't want to have to buy a new car but when spring comes around thank you for watching i really do appreciate your time here please feel free to ask me any questions about this project or your own projects and i hope to see you in the next video

Channel: Home Garage

Views: 101,742

Keywords: stihl, husqvarna, echo, ryobi, troybilt, troy, troy-bilt, strimmer, trimmer, homelite, poulan, craftsman, craftsmen, weedeater, weed, eater, grass, trim, edge, edger, yard, yardman, will, not, start, won't, run, starting, running, starts, runs, work, working, works, fix, problem, solve, help, diy, garage, inside, house, home, spark, gas, fuel, line, mix, cycle, 2 cycle, 2 stroke, stroke, can't, why, my, carb, carburetor, rebuild, kit, rebilt, shaft, pull, rope, string, engine, kill, switch, rev, rpms, speed, head, on, off, bolens, arrestor, clogged, wacker, lawn

Id: IOotUxoTR5w

Length: 12min 53sec (773 seconds)

Published: Fri Jun 17 2022