Any small engine guys? Chainsaw issue

Hey guys, figure I’d see if anyone here is good with small engines. I’m having some problems with my saw. So a little background on it. It’s a 20” Craftsman 538.35098. I had originally bought a 16” and the saw was solid. Only problem was it wasn’t big enough to cut a big tree that I needed to take down. Sold the 16” and grabbed a 20” got sold on the fact that it was supposedly made by Husqvarna. This saw from day 1 wasn’t a good starter. But it did run. After cutting that tree up I used it the following year to cut another tree up. Ran but still was a bitch to start. I think the following year I was trying to help out a buddy cut some brush and wood up and couldn’t get it started. Ran out and got a new plug (E3) and after about 30 min finally got it running. Ran it for maybe 20 min and then it died and wouldn’t start again. Tried to use it a few more time to no avail.

Fast forward to a couple weeks ago. Decided to take it apart and figured the carb was dirty. Cleaned the carb out and sprayed the fuel lines out. Also cleaned the arrestor and muffler just Incase. It fired up and I ran it for a few min. Cut a piece of wood and then it stalled and wouldn’t start again. Decided to get a new plug (NGK), ordered new fuel lines, fuel filter, fuel cap, and purge bulb. Also got some premixed gas just in case my mix was off or the fuel was stale. Won’t fire back up.

The plug is getting wet, so it’s getting fuel. It does have spark. The plug is gapped to .025 (factory recommendation). Neither the E3 plug or the NGK makes a difference.

Perhaps it’s a ignition coil? Not getting enough spark or something with the timing? I don’t know what else it could be. I might just order a new ignition coil. But don’t want to just throw parts at it. Any input would be greatly appreciated!

 

I'd check the ignition coil first because it's cheaper, but it could be a compression issue. Rings could be worn out.

 

you said its new? or is a used one? Doesnt sound like its a carb issue, maybe a loose wire/sensor for the shutoff switch. If you take the spark plug out and plug it into the wire, ground it to the head somewhere and pull it a few times the spark should be good and you should be able to hear the spark pop and see it.

 

I didn’t take a look at the rings or pistons. The saw has only ran a few times so I wouldn’t think they are worn or there is any scores or anything in the cylinder.

Saw was bought brand new, however now it’s a few years old. Has only ran and been used a few times. Kill switch is good and so are the wires. I put the plug on the head and seen blue spark. Didn’t hear a pop though just seen spark

 

They are pretty simple, sounds like you have spark and fuel. My weed eater had similar issue and turned out to be the key on the flywheel was sheared. I had the brush cutter blade on and when it hit a stump it sheared it. If yours was something like a cutoff switch or low oil switch it wouldnt spark...only other thing to check is to see if it actually has compression. Stick your finger in the spark plug hole and crank it, it should try to push out, if its weak compression it wont. Theres no belts/chains for timing just a halfmoon key that keeps it in the right time to run.

 

I read something that adjusting the bolt that holds the coil down actually did something with the spark timing or something crazy. Sounded like BS to me but I don’t know. I did read something about a key in the flywheel. But I assumed this wasn’t my problem since I was able to get it fired up and run for a short time. Also assumed because of which, I also had compression. I’ll double check that just to be sure. A new coil is only $25 so maybe I’ll just take a shot at that if nothing else. Spark did seem a little dim if I remember correctly. Maybe I’ll play with that a little

 

Well I got compression. Took the plug and rested it on top of the head. Gave it a pull and some fuel ignited. Assuming my spark is good lol. Maybe I’m getting too much fuel and it’s flooding. Just putting my thumb over the plug hole I got a bunch of gas on my thumb. Should I adjust the carb?


Also remember times before trying to start it was getting a bunch of gas in the muffler. I unbolted it and could tip it and a bit drip out.

 

When you replaced the carb did you adjust it once the engine warmed up? Ive always had to adjust a new carb before it would run right.

 

I never touched any of the adjustment but the chain moved on idle so pretty sure it needs adjustment anyways. Also it would die on idle most of the time. Adjusting it should help with that as well. Just not sure why the hell this POS doesn’t want to start.

 

Did the new carb come with a carb adjustment tool? I still think the carb just needs adjusting along with some fresh fuel in it.

 

Never replaced the carb, just took it apart and cleaned it thinking maybe it was gumed up. Replaced the fuel lines, fuel filter, purge bulb and gas cap after I cleaned the carb

 

My money is on the carb being out of adjustment. Not hard to adjust as long as you have the right tool.

 

Yea I’m kinda learning towards this ATM. There is a tuning port however I thought a philips or flat head would work. Looks like a spline drive is needed to adjust. I’ll just have to take the case off again so I can get to it and use a pair of pliers. Not really sure how to properly adjust it and trying to do so ripped apart and not running is going to be a challenge.

Thanks for all the replies so far!

 

I also call carb. Too much fuel too soon and you'll just be flooded and it wont ever start.

 

Yea that’s what I think is happening. Plug seems awfully wet

 

yeah I was chasing simple stuff too, thought maybe carb issue but it wasnt it was timing, finally gave up and didnt even think to look at the key, they put a new key in it and new carb and it fires right up.

The coil does have to be a specific distance (for your chainsaw)from the flywheel otherwise it wont start as well BUT it wont have the right spark if its too close or too far. I dont think theres any timing adjustment as far as I know...just spark or no spark.

or sometimes they are just lemons. I had one that ran about 6 times and the whole thing seized up, I tossed it into the woods as far as I could. I ended up giving the POS away and getting a new chainsaw. Now I only use Stihl.

 

could be something in the fuel seat thats staying open. and letting fuel run in.

 

I also only use Stihl. I've beat the living hell out of Stihls and they keep trucking. Solid little machines

 

I’ve thought to myself a bunch of times why didn’t I just buy a nice Stihl or maybe an Echo. Bought it when I first bought my home. Didn’t have a bunch of money at the time and the tree needed to come down. I live in the city currently so don’t have much of a need for one. Just wanted one I could use a few times here and there. I’d love to buy a new house with some property or maybe a hunting cabin with some land or something. If I ever do you can bet your ass I’ll be spending some good money on a decent saw. I’m ready to throw this thing through the wall.

 

I do tons of small motors from gas scooters of all brands, go carts, chainsaws etc.

You need three things. Gas, compression, spark.

You have compression, you have spark, and you have gas. But seems like not the right amount if the plug is completely soaked. Take the plug out and pull it like 10 times and let it dry out a bit. You’ll have a few adjustments on the carb which can be adjusted with a small flathead screwdriver. Some carbs have a H and L. Stihls have 3 adjustment screws.

See if you can find your factory settings online but if you cant. Trial and error. Screw both in all the way until they bottom out. Screw them both 1 turn out and adjust from there.

If it starts and it’s super rich, lots of smoke, hear it kinda bogging etc. Then lean it out (less gas). If it runs and it’s kinda higher pitch and fast revving give it more gas. You’ll figure it out after tinkering a bit. Sometimes they like to be WOT when starting and use choke etc. Every saw is different