Generator Low Voltage - Fixed

hey guys welcome back so today i'm working on this briggs and stratton elite series generator and pretty excited about it i've been wanting to work on one of these for a while but never been able to get my hands on it well now that it's here i can see there's something very different and wrong about this generator it has the standard briggs and stratton airbox with the standard exhaust system that you'd see on most of their stuff like the storm responder generator but this engine is very out of place this is a briggs and stratton generator and briggs is famous for making small engines you would expect to see a briggs and stratton engine on here but that's not what this is i've seen this set up many times you know it's on generac ryobi power stroke and a bunch of others but this is a standard 420 cc engine made in china and the dead giveaway i mean besides the shape of the head is this carburetor this is a clone of a honda gx 390. anyway kind of getting off on a tangent there this generator i actually didn't buy a subscriber who lives locally reached out to me and asked for help so he dropped it off today now this has a bit of a story to it it used to be on a food truck it has 372 hours on it customers were complaining that it was too loud so he put it into storage for about five years and you can probably guess what happened next and he brought it out of storage recently it wouldn't run off a choke he cleaned the carb and still wasn't running well so we went out and bought an oem carb still wasn't running right so he ended up dropping it off to a friend who's an auto mechanic and he he went through it he cleaned up the tank the fuel lines and figured out that if you unplug the solenoid the engine runs fine so that's where it's at right now but that's actually not why it's here either the issue now that it's running he can see that there's a power problem it's producing somewhere between 35 and 40 volts which is somewhat unique usually the ones i get either they make power or they don't so this one's somewhere in between and i haven't dug into anything yet but my guess would be the avr but before i just jump into conclusions and throwing parts at it i do want to check all the windings figure out what the ohms are at get a and also i want to pull the cover off the head and visually inspect everything make sure there's no red flags you can check the ohms of the main windings on the stator just through the outlets and that's what i'm going to do here now i've got the main circuit breaker on you want to make sure you have that on or you're going to get no reading whatsoever and this test can be done either through the 120 outlets or the 240. i think the 240 is a little bit easier because i don't know how these outlets are wired you know is this leg one leg two or is leg one the top two and leg two the bottom two sometimes visually they show you but in this case it's not really clear to me so i'm gonna use the 240 and the neutral is opposite the ground the ground wire is the one with this tab so that's neutral then we've got leg one leg two and before you do this check the internal resistance of your meter in this case this is 0.1 ohms so you know if i get a reading say of 0.6 i can subtract 0.1 from that to get the true reading now i don't know the reading for this but generally between 0.2 and 0.5 is a good reading and if you don't know the reading just compare the values between leg one and lake two that's a good reading we're at point two and the real reading is point one so that's excellent and the same so both sides are consistent that's very promising it doesn't guarantee your stator is good for a couple reasons but i guess the first reason being that this is a low voltage test this is a cheap meter but if that number was really high or zero or open lead then you got a problem in this case things look okay i don't think we have a problem but again this is just testing that we have something within range it's not a guarantee let me get the cap off the power head and we'll do the rest of the testing down there [Music] yeah it's surprisingly messy in here not sure if there was a critter or or what but that's a bit of a red flag anyway it's really hard to see anything the wires are really packed in here so i'm gonna just pull these bolts on the avr so we can get a better look okay well besides all the junk that was in here i am seeing signs of a potential issue if you look here in the windings especially that one toward the bottom it looks pretty dark and crispy the rotor itself looks to be in pretty good shape so i am suspicious of the stator you know maybe that's not the main winding it could be one of these windings here providing power to the avr so i'm going to get the wires unplugged from the brush and you know this wire here which is what is supplying power to the avr and test the ohms on these windings as well as the ohms through the brushes yeah and it almost looks like someone was in here before me this here the zip tie generally it's a specialty zip tie that's screwed into here but i'm not seeing that so yeah maybe i'm not the first but anyway let me cut this zip tie off unplug this connector and pull the wires here and that avr will come right out okay so first i'm going to test the resistance through the brushes now most rotors i measure are between 50 and 70. but you know anywhere between seven and a hundred might be okay depending upon the generator yeah it's hard to get a good reading but it seems like we're in the mid 80s which is a bit high but you know we're going through the brushes so that might be expected but i'm going to pull the brushes off try to get a reading directly on the slip rings and the brushes are a bit worn but i don't see any damage okay 47 ohms so the rotor is actually in good shape other than the fact that you know the brushes are a bit worn the slip rings themselves yeah the slip rings themselves are also pretty dirty so those could be cleaned up you know potentially that is the issue focus so the rotor ohms is very good at 47. through the slip rings it's like double that so those slip rings are pretty dirty most likely have to be cleaned but yeah let's continue on here now this color scheme i'm a little bit less familiar with usually it's two blue wires those are the ones that supply power to the avr and then the green and the white are more the sense winding which i don't suspect is the issue here because even if that was bad usually the the default is that the avr goes to full power which we're not getting but i'll check them both so on the yellow wires i would expect somewhere around an ohm give or take maybe half an ohm okay half an ohm that might be low but not too concerning and then these wires i would expect to be similar to the main winding probably around point two point three and we are so i'm actually feeling pretty good about this stuff you know we already tested this winding the main winding so we know that that seems to be good this down here is actually power for that fuel solenoid which i'm not too concerned about right now really this one and this one that's what you need working to get full power this generator is bonded to neutral so these are the ground wires connected here and if you look we have one white wire here and the other white wire here and that runs over to here so what i want to do is just temporarily disconnect the ground wire and then check each winding to the ground to the frame and make sure there is no connection okay so attach one lead to the ground to the generator and then just check the two hot wires which is the bottom one here there's no connection top one no connection then we'll just check one wire from each of these windings okay good okay well that's all i really wanted to check we don't have any connections to ground the ohms readings are present main windings look good from a gnome's point of view and the yellow wires seem a bit low but i'm not overly concerned about that yet i'd say that's the smoking gun here is probably the resistance through the brushes to the slip rings not saying that's the problem but that is a problem so i'm going to put it back together just like it is bring it outside see what we get bring it back in clean up those slip rings maybe put some new brushes on and try it again you ready for a quick test i just have a light hooked up in the kilowatt so i'm going to start this thing check the hertz and the voltage and see what we get 35 volts 59 and a half turns i'll turn the light on you can just see it glowing so i am very suspicious of the avr and that is the easiest thing to change out so i'm going to swap that out first see if there's any change and assuming it does come back you know i'll still need to clean those slip rings up but if anything i'm willing to bet we have avr issues so this is the assortment of avr's i have to choose from now this is the one i pulled off and the important thing to check here is the capacitor this is 470 and all these are actually 470 as well so i could use any one of these and this one's actually a little bigger at 680 but when comparing kind of the board design this one here seems like it's an exact match as far as the components go the placement the count and they're made by the same company so i'm gonna give this one a try okay [Applause] very nice so may have dodged a bullet on this one it's making power 108 volts engine speed is 59 hertz so voltage is low engine speed is low i'm going to pop that new avr off turn the potentiometer and check the voltage again i want to get it to about 120 volts and then i'll worry about the engine speed and if memory serves i think it's counterclockwise to crank the voltage up so i'm going to do two complete turns and see what that gets us [Applause] i went the wrong way okay i went the wrong way i think there's a little confusion here in my head i just worked on a generac where counterclockwise was up and on this one counter-clockwise is down so there is a difference apparently between uh potentiometers and what you're gonna see so let me turn that two turns back i guess the good news is we know each turn changed at about two volts so i'm gonna turn it two turns back to get it to where it was which is 108 volts and then i'm guessing i need to go about six turns uh clockwise to get it up to 120. okay so we're back where we are one two three four five we'll stop at five and a half for now 120 121 that's good so now that we have proper voltage proper engine speed i'm going to start it up throw 3000 watts on it make sure things stay good and while it's running i'm going to check into the solenoid issue this is the wire he unplugged to get the engine to run right so right now i have the meter set to volts dc which i think is what would be going to the solenoid now it should be zero when the engine's running so that's what i want to check and the only time you should get voltage is when you shut the switch off which deploys that plunger in the carburetor so that'll basically hold it until the engine powers down and the coils lose power and a thing opens back up again [Applause] yeah it seems to be okay the only time it sent voltage into the solenoid winding is that shutdown and that's exactly how it should work and after plugging this in the engine kept running fine so i don't think we have an issue there and on the load side we also did pretty well too 3000 watt load engine speed held at 60 hertz voltage i was dead on i think it was around 120 121 volts and those numbers are all good so i think electrically and mechanically we're in pretty good shape i'm just going to get this thing back inside clean it up a bit clean the slip rings and the exterior and change the oil actually the oil is very overdue so i'm going to do that now while it's hot perfect so just spending a minute starting to clean this thing up and you know the exhaust just gonna hit it with a little bit of scotch brite and soapy water that'll take a lot of this rust off and make this thing look a lot better so okay so i get the brushes off again gonna clean those slip rings i am not really gonna be able to show you much when i'm doing this but the way you do it is well the way i do it is with a piece of scotch brite cut roughly to the diameter or the width of the slip ring and i have a rotor here to show you this one's already been cleaned you know you're just going like this and you know you rotate the engine a little do it some more until you get all the surfaces cleaned up now you do have to be especially careful you see down here there's a wire connected to a terminal and same on the other side when you're polishing these rings you do not want to knock into that wire and knock it off because if you do your rotor is going to be junk so let me spend a few minutes cleaning that up and i'll show you the end result okay so that's the end result you know it's not perfect but i mean to be honest it's really hard to clean with this end housing on if you want to do a really good job uninstall the stator and then clean the slip rings but you know i felt like i was pushing my luck especially with those wires so close to the slip ring so that's a pretty big improvement you know i'm happy with that now as far as the brushes go i have new brushes on the right and the used ones on the left and they're not as worn out as i thought so i'm going to put the original brushes back on do another ohms test and see if it's improved at all now that it's cleaned up so the first time we checked the resistance through the brushes we were at somewhere around 85 86 ohms and direct to the slip rings i think it was 47 so the brushes will add a bit of resistance but ideally it shouldn't shouldn't add too much yeah that's good 49 ohms through the brushes so you know my my theory on why these avrs blow is that the slip rings get dirty it was double the resistance through the brushes as it normally is so the avr probably had to crank out a lot more juice to reach 120 volts and ultimately led to it failing so now the resistance is pretty negligible through the brushes and we got a new avr anyway so hopefully this will last a while so i'm gonna throw that evr back on get it all clipped in tighten down throw that cap back on [Music] okay let's do one more quick test you know now that i've cleaned those brushes i want to make sure i haven't changed anything for the worse [Applause] it's a little bit slow gonna let it warm up a bit see if it speeds up so okay well i didn't mess anything up you know we still get good power output but the engine speeds a little slower than i would have expected given what i'd said it to earlier that's the first thing the second thing is that it is hunting a bit and i didn't notice that before so this carburetor thankfully has a drain on it and this is a new carb so i doubt there's much going on here but i want to crack that drain just make sure there's no water in the system and the second thing is that you know this thing was hunting under no load and you know i thought back to something that the person mentioned who dropped this off and that's once they got it running it was running slow so he did already drive the screw in to increase the speed and i did it even more the other day which doesn't make a lot of sense why you would have to do that and when looking at the adjustment screw here on the side you can probably see if this wire wasn't in the way that the screw which is right there is driven all the way in so there's really no adjustment left and that's that's not right there should be some play on that to go in either direction so what i'm thinking happened is that the spring here on the governor arm was most likely disconnected and put back in the wrong hole so you can see the six positions there and it's on the second one out from the governor shaft and if you look at the third one out you can actually see what looks like a bit of wear so i'm guessing that that's where that spring is supposed to go now by putting it on the wrong hole cl to the left you'll decrease this the spring tension and decrease the engine speed so i'm gonna move it one further out it's gonna pull the spring harder and run the engine faster so i'm going to back that screw back out reset the speed and this also adjusts the sensitivity of the governor the further in you go to the shaft the more sensitive the engine is under load you know as far as maintaining the speed goes so you bring it in too far it actually can just start hunting and oscillating for no reason because it's now too sensitive so that's probably what's going on here but let me just drain the bowl move the spring back off that screw and then i'll reset the speed and see if things sound any better yeah there's no issues with the fuel so must be the position of that governor spring uh it's just too sensitive where it's at okay let's try this again i dialed the adjustment screw way back so hopefully it's below 60 hertz when i start this [Applause] [Music] yeah that's a little slow yeah we're good okay good the hunting the surging it's gone and i retested it under load just to make sure the governor response was good you know if you move that spring too far out you're gonna get something called governor droop which is basically you apply a load and the engine speed sags too much and i didn't see that it actually held just as well as in the other spring position so the sensitivity is fine you know we do have a little bit extra now on that adjustment screw so we can make it faster if we wanted to and you know most likely that's the reason for the poor running you know that the person who dropped this off had mentioned and ultimately unplugged this wire thinking that that was the issue i think most likely it was the fact that this spring was too far in the governor was too sensitive and it just couldn't stabilize the speed as well as it should have so now that that's all set you know this thing is is pretty much done and to be honest i didn't give it much hope i did not think that powerhead was going to come back but surprisingly it was just the avr and despite the rant in the beginning about who makes this engine it is a good engine and i don't want to kind of diminish that i mean this is a good setup i like this generator a lot it was just a little shocking anyway hope this video helps someone thanks for watching

Channel: James Condon

Views: 237,979

Keywords: 030471, AVR Replacement, AVR, Automatic Voltage Regulator, Briggs and Stratton Elite, Brushes, Chinese, Chinesium, Engine Speed Adjustment, Fixed, Fuel Solenoid, Generator, Governor Droop, Governor Sensativity, Governor Spring, Hertz Adjustment, Low Voltage, No Voltage, Ohms, ROM Adjustment, Slip Ring Cleaning, Slip Rings, Small Engine, Troubleshooting, Voltage Adjustment, 030471-01

Id: awBo1DObr0o

Length: 37min 16sec (2236 seconds)

Published: Thu Oct 29 2020