A customer brought in a Husqvarna 450 chainsaw that he had tried to tune up using aftermarket parts. Despite having a new carb, coil, air filter, and whatever else, it still wouldn't run. You won't believe why. #smallenginerepair
I have seen and fixed this issue before. If you look at the IPLs for the Husqvarna 450, they used a different coil and flywheel combination on the older 450s built through about 2011. While the parts will physically bolt on the newer and older saws in any combination, you can't mix and match. This is because the magnets on the newer flywheels are way more advanced relative to TDC than the older flywheels. Put an older coil on a newer saw/flywheel and the spark plug will fire before the piston is high enough to cover the transfer ports. My suspicion is that Husqvarna used to use a straight CD ignition on the older models that maybe only had a two-step advance curve for starting and running. The newer coils are most certainly fully electronic with a completely variable advance curve. Therefore they need to get their impulse to charge the coil earlier, so they can fire at any point throughout a more broad advance curve. The aftermarket doesn't seem to differentiate between the two coil and flywheel part numbers, which makes this issue even worse if you're not using OEM parts and following the parts list for your particular saw.
That sir is the answer I was looking for. I went through the 450 catalogs and thought I actually found three different part numbers. This follows a theory I have about aftermarket carbs. People say they are crap but I believe a lot are being sold for models they won't actually work on. Many times its because the impulse hole doesn't line up properly. Thank You.
yea i have seen this before also and in the 440 saws too you have to run the right flywheel with the right coil. The things we run into when customers try to fix their stuff then bring it to us , but i quess thats why we do what we do.Good job.
Now that was a great answer, especially to us rookies. Well I'm 57 but a rookie at servicing Stihl and Husqvarna. I love this channel and haved learned allot. It's sad that some of the maintenance channels such as his just don't take time to respond to questions. He's always answered all my questions no matter how silly.
I was thinking its a starter mechanism issue and when that wasn't it, my 2nd pick was the coil. I was hoping it wasn't the coil so I could get schooled a bit though😅
Great vid! LOL, folks won’t believe you. I’ve got an old Super 041 Stihl with a original electronic SEM ignition set up that starts up in the correct direction but will occasionally “pop” backfire & run backwards. Too late timing is what I think.
Good video Scott! Never have I seen anything like that before and I've owned and worked on a lot of saws although maybe not enough. I was thinking before you showed us what was wrong that the issue might have been that "new" coil he put in. Thanks for the upload man. Love your channel brother!
Coil was my thought for sure but no idea so I'll go with your explanation! I have to go down to my Husky dealer Monday and he's a very great saw mechanic like yourself so I'm going to run it by him. If I don't come back he has same explanation!
That's bizarre. I wouldn't guessed a coil could do that.. I agree with your assessment of the situation, still weird. I'm surprised it started as well as it did. I have heard of old two stroke dirt bikes running backwards
One day I discovered my old suzuki dirt bike would run backwards if I bump started it rolling backwards down hill. Riding backwards is truly a circus act!
My thought, after starter, was key was sheared, crank had gotten twisted, or the coil was wired incorrectly and had reversed the magnets (if thats even possible?). Glad to see some of the comments have an explanation.
Yes it can be tough sometimes when working with unknown parts from less than reputable suppliers. On the other hand, maybe he just ordered the wrong coil.
Surprised it didn’t blow the plug out! The plug threads on my Husky gave-up and my plug boot got burned up. Have an amazon coil installed now; And while it runs, I'm suspect of poor timing issues down the road.
One more question….might be a good video….What process would you go through to get a saw going that hasn’t been run for three years and was just put on the shelf after using for two days? 😞
I would say any of my videos where I say "customer states hasn't been run in a while" would cover it. Theres nothing I would automatically do but after looking there are probably a lot of things that might need attention. When the right saw comes along I'll present it that way.
When you said that he replaced the coil and you mentioned the imposter spark plug it gave it away. He bought one of those Scamazon kits that probably included a new Chinesium coil and spark plug.
Can't remember the brand but that doesn't matter because a lot of people have asked and I've gone back to look but have never found it. I really like that cheap screwdriver and I should probably start searching for a backup. If I find one I'll be sure to post a video.
@@TheGreasyShopRag Dangit! lol. I will be watching if you figure it out. I just found your channel a few days ago because I was trying to do some maintenance and cleaning on my 2020 572 XP and my 2013 550 XP. Keep up the great work, I enjoy your style and I love hearing about less than smart chainsaw owners! lol.
I agree the ignition was advancing and would turn the engine the opposite way. As soon as you started it, I remembered the parts you said he changed and immediately said ignition coil. Can’t trust all those reproduction parts.
Advanced timing is most likely the answer but as it turns out the coil may actually be good but doesn't match this flywheel. Check out jackofalltrades comment.
Thats a new one for me. Definitely archive that one. . Ive found that when you get a pre assembled gray market saw, with the so called warranty. You normally get decent parts. . But you order individual parts or a long block thats not fully functional. That has no warranty, its a full on craps shoot to wether the stuff is functional in basic design.
They might run their saws backwards like how they drive on the other side of the road thats backwards to probably why a bunch of them here can't drive for shit
Bad IGN Module 😮😀 I’m Guessing and Yes I Was Correct 😀 And I Agree With Your Theory There Is an Internal Failure Of The IGN Module Only Seen One Run Backwards It Was an MS-200T Same Fix Have Had Many Redmax Strimmers and Echo Hand Held Blower Coils Pop And Backfire Thru The Carb or Fire and Jerk The Recoil Out of My Hand It’s Always The IGN Module I Like You Verify The Integrity of The Flywheel Key and Also Check For Spark With The Kill Wire Disconnected When They Fail They Dont Just Fail From No Spark It’s Got Spark But Out of Time 😎😀
Maybe it kicks back faster than the dogs can return. I dunno, that starter was a bit jacked up. Maybe the dogs actually are what caused some of that sloppiness in the starter.
I think you're right. I had thought about it for a while and came to the same conclusion. I think i've mentioned this before but you have taught me lots on the procedure and diagnostics of troubleshooting chainsaws. @@TheGreasyShopRag
That could only happen on a two stroke, cause it pulls fuel from the bottom end. Couldn not be possible on a 4 stroke. Whould be interasting to se if it was sucking in through the exhaust
I have been burned several times with chineseum parts. I avoid them like the plague honestly. Got a chain brake handle for a Husky 359 off Fleabay, was almost 3/4 of an inch too narrow. No where near OEM spec. Chinese carbs? Hell no! Rebuild the OEM every single time. And don't get me going on the stolen design, knockoff, deceptively marketed to sound German or Swedish saws. I've even seen where these "companies" over there are selling knockoff parts that say "Sweden" on them or "Germany".
Those aftermarket companies would be doing themselves a big favor if they would just verify fitment AND runability before offering a part for certain models.
@@TheGreasyShopRag I don't think they care honestly. When I was a kid we used to call it "Fly by night" operations. Just peddling junk and then move on to peddle more junk. Appreciate the videos by the way!
www.ebay.com/str/thegreasyshoprag It doesn't look like I have one listed but that coil should cross to other models like the 41, 136 and 141. I'll let you know if i find one in the garage.
Husqvarna is loaded with allkind of coil and quality issues nowadays. No big news there, but sir please don't bang customer's equpment against the table. I know why you do it, but still please don't.
