Chainsaw/small engine woes

[tnguy]

So sometime last summer I went to use my chainsaw and it wouldn't start. Poking around a bit, the filter fell off. Fuel lines gone bad. So I ordered up a repair kit, (spark plug, air filter, fuel filter and fuel lines) and just got it all installed. Still no start.

If I pull the spark plug, I definitely get a spark.

I think the fuel is good. If I pull the exhaust module, I can see fuel spraying out (and managed to get it to catch fire). I believe I have the fuel lines wired correctly, outlet of the priming bulb to the tank return.

Tried fresh, no-ethanol fuel.

This thing doesn't even make any attempt to want to start. I even had someone spray stuff at the inlet while pulling and not even a stutter.

Compression feels normal.

Air, fuel, spark. Everything should be there. Hard to think that the timing could be out. I'm stumped. Any thoughts?

[TripleDigitRide]

Is there and on/off switch? Is it in the "on" position. Hey, ya never know.  :cool:

 

You using the choke?

 

Maybe the carb is gummed up? Can happen if it's been sitting a while.

Edited March 16, 2014 by TripleDigitRide

[Caster]

Try another plug. I've seen bad plugs right outta the pack. I've also seen spark plugs that wouldn't fire under compression.
While you're in there, sand the magnet on the flywheel and the faces of the coil. Regap the coil with a dollar bill.

[Dane]

What kind of saw? Sent from my iPad using Tapatalk HD

[tnguy]

Definitely on. Believe me, I checked that several times. I've been bitten by that before. Also tried both choke and no choke.

Possibility the carb is gummed up. Though I am definitely getting some fuel but maybe it isn't enough?

I could try a new plug. Or maybe just put the old one back in. Possibly the spark is just not good enough so I'll give the regapping a go tomorrow.

It's a cheap Poulan. I can't remember what model. I think it's an 18" blad. Edited March 16, 2014 by tnguy

[10-Ring]

Clean that carb if you even think that it is a possibility that it is gummed up.  That is a very easy carb to clean.  I've had trouble with a couple of small engines this year and draining the gas and/or cleaning the carb got them running like champs.  This ethanol fuel just will not sit for any length of time at all without gumming up.

[gregintenn]

Whoever got the ball rolling to mandate ethanol to be added to gasoline should be drowned in the stuff.

[tnguy]

Yeah, I think ethanol screwed it up and I've only been using non-ethanol since. I threw away my gallon of mix just in case it was left over ethanol gas. I guess it wouldn't do any harm to give it a proper clean. I guess the mixture may be far enough off.

The spark didn't look amazingly strong when I tried it in the dark but I kinda don't expect it to be especially so on a small engine like this. The old plug gave a much weaker spark though so it's an improvement. Edited March 16, 2014 by tnguy

[gregintenn]

I have several things sitting around that aren't running because of ethanol.

 

Not only are we screwing up small engines everywhere, we are also raising the cost of a necessary food staple for many third world countries.

Edited March 16, 2014 by gregintenn

[seez52]

Go to Autozone and get yourself a gallon paint bucket of Berrymanns carb cleaner. Not the gunk brand. It has a metal basket inside. Disassemble the carb and let it soak overnight. After soaking run it under hot tap water to wash off the Berrymans and carefully blow it out with compressed air. Reassemble with new diaphragm.
The gallon can will cost $25-30 but seems to last forever. Use rubber gloves when handling the Berrymanns or you'll be wearing that cologne for days. This routine will ungum most carbs. Although some of the small weedeater ones are lost causes.

[Mike.357]

soak the carb down with Gumout.  Just access it as best you can and spray the heck out of it.  Repeat the process a few times.  Then give it a try.  I have success with this in the past on a quad that got gummed up.  It did not take long to get it to fire.  It is a cheap try at any rate.

[NashvilleStage]

My guess is that it's either the carb not putting out fuel, or the spark timing is off. If you're getting spark and the carb was bad, the starter fluid should have given you at least one or two good bangs/puffs though. If the timing is off, it'll either not start, backfire, or kickback. Try pulling the flywheel & look at the spindle that it slides over. If there's a key, make sure it's not bent or sheared. If there's just a spline or a milled flat, make sure there's no damage or excessive rotational play when the flywheel is on there. Check the inside of the flywheel as well for damage.

 

A buddy of mine had a string trimmer that wouldn't start for anything. He finally pulled the flywheel & reinstalled it. Started right up. It wouldn't stay fixed, though. Best we could figure was that the flywheel just wouldn't stay in place & eventually fell out of timing again.

 

One other thing: pull the muffler & try starting it again with starter fluid (watch your eyes & ears). I've heard of mufflers becoming obstructed from excessive oil and/or extended running at low throttle (where the muffler is not hot enough to burn off the exhaust oil), or from rust / bugs / whatever. Worth a shot. If the muffler is full of oil or carbon deposits, throw it on your outdoor gas grill & bake it with the cover down at max for a while to burn out the interior.

[Mike.357]

yeah,  the muffler thing is a good idea.

 

My leaf blower has a spark arrester in the exhaust.  If it gets gunked up it will not run.

[Fourtyfive]

I put that Ethennol fixer in my 5 gal can every time I fill it.

[Mike.357]

I have been using Sta-Bil for a few years now and have had no problems getting gas powered tools to run since beginning use.   I avoid ethanol gas.  Will drive to find 100% gas if need be.  This with Sta-Bil has solved all fuel related and lack of use over the winter months.  I don't even mess with draining fuel tanks anymore.  Come spring it all fires up just fine, every time.

[NashvilleStage]

I have been using Sta-Bil for a few years now and have had no problems getting gas powered tools to run since beginning use.   I avoid ethanol gas.  Will drive to find 100% gas if need be.  This with Sta-Bil has solved all fuel related and lack of use over the winter months.  I don't even mess with draining fuel tanks anymore.  Come spring it all fires up just fine, every time.

 

+1 on using Sta-bil. I always add it to my gas cans (even ones that get 2-stroke oil), and treat the gas as I fill them up at the pump. That way it mixes thoroughly, and the gas doesn't sit around until I remember to treat it.

 

I still drain the fuel tanks & run engines dry at the end of the season, though. I figure that while the gas might not turn gummy, it'll eventually evaporate & leave deposits. Or something.

 

Okay, okay... I'm anal; that's why I do it.

[tnguy]

Already had the muffler off. I had the flywheel off (I was starting to believe I would have to disassemble the thing completely to get the new fuel lines in).

If the rain stops today, I'll dig out the compression tester. I'm beginning to settle on the idea of it being the carb though. I'll order up a carb kit and get some cleaner.

[Guest Lowbuster]

I have been using Sta-Bil for a few years now and have had no problems getting gas powered tools to run since beginning use. I avoid ethanol gas. Will drive to find 100% gas if need be. This with Sta-Bil has solved all fuel related and lack of use over the winter months. I don't even mess with draining fuel tanks anymore. Come spring it all fires up just fine, every time.

I do this too. No problems for years.

[peejman]

What everyone else said about ethanol and small engines. It's bad mmmmmkay.

If cleaning the carb doesn't fix it, sometimes you can buy a whole new carb surprisingly cheap on eBay. I got an ignition module for my ancient homelite saw off eBay a year or so ago.

[TnShooter83]

Here is what I do. I spray CARB CLEANER directly in the cylinder through the spark plug hole.

It will either start or not start.

 

If it starts it's a fuel issue.

If it does not start it's a spark issue.

 

If it is a spark I pull the plug and ground it to a GOOD ground and look for a spark.

It needs to be hitting consistently and fairly bright. If that doesn't help I move to the magneto.

I regap and clean it. I use 600 grit sand paper.

If that doesn't help I resort to throwing thing and saying bad words.

Sometimes, but rarely this seems to help...lmao.

 

If it's a fuel issue, I pull the carb and clean it.

Pull the jets and make note of how far any jet or air screws are turned in.

COUNT THE NUMBER OF TURNS IT TAKES TO REMOVE THEM.

REINSTALL WITH THE SAME AMOUNT OF TURNS. DO NOT GO FURTHER.

This will usually get it running. You can fine tune later.

You need a piece of wire to stick in the small port and venturies .

Just find some electrical wire and strip it until you find the size you need.

Then spray all the ports and hole you can see and get to. Wear safety glasses and keep your mouth closed.

You will get wet doing this.

 

Alternatively soaking the whole carb and all it's part are better, but it takes longer and can damage plastic parts.

So be careful. I'm just "cheap" and don't want to spend $30 on a can of cleaner. Not unless I have too.

The $4.00 can of Carb Cleaner usually does fine for small carbs.

[tnguy]

I have it a few pulls this afternoon and the first two pulls, I got a "pop" at the start of the pull. I wonder if it could be flooding (I had the choke off though). I'm going to try and get the carb done this week. I have the cleaner and I'll be ordering up the kit.

[z0mbies fear me]

Thought mine was messed up last fall. Turns out the handguard was in the full forward position. After about an hour of pulling on the rope I happened to hit the handguard back into the right position and she fired right up. Made me feel very dumb :/

[tnguy]

Definitely not the case. Don't even have the chain on right now.

[seez52]

Rather than starting fluid use wd-40. Spray directly into the carb while cranking. You should be able to get it running on WD if everything else is good. This will tell you if its the carb. Doesn't take much to get it going

[tnguy]

I'm sure I must have some wd40 but I haven't seen it in a while if so.