My husqvarna 136 is killing me- even after carb kit- please help

[clydesdale6]

I have a new spark plug that I have tried as well. It doesn't matter whether I have the old one or the new one, the saw behaved the same and they both end up with the little black fits and soaked. I thought the black bits could be carbon, but they are soft and rubbery or like silicone. When I rebuilt the carb, I even bought the walbro tool to make sure the metering lever was where it should be. I even cleaned the carb with an ultrasonic cleaner. That is why this thing is killing me. The saw ran better before the carb cleaning. It actually ran better before I replaced the fuel filter and fuel line. So, just removing the carburetor and replacing the fuel line Disturbed something. When I opened up the carburetor, the little filter screen inside the fuel pump area was filled with Sawdust. That is when I thought a carb cleaning wood definitely fix the problem. Any other diagnostic ideas before I put a cheap Chinese carburetor on? Thank you to all for the help.

 

[Matt93eg]

With the plug dry and grounded to the top of the cylinder, how good and consistent does the spark look when you pull it over?

I rebuilt my Dads 136 because the choke plate screw fell out and got sucked into the engine which cracked the piston. Before tearing it apart the saw would fire and run, just didn't run good.

So I tore it apart, replaced the cylinder, piston, crank amd everything. Put it back together and it popped one time and then flooded amd soaked the plug. After that it would only soak the plug and would not hit a lick even with starting fluid.

I pulled the recoil and spun it over using a drill and my spark was weak and then the plug wouldn't spark at all. You could come back a while later and spin it over again and get a weak spark again for a few seconds and then once again no spark.

Bought a stupid Chinese coil that was dead on arrival. Threw it in the trash and bought an OEM coil and bam saw fired right up.

I say that to say my coil crapped between tear down and putting back together. Coincidental I know but it happened. So pull the recoil, spin the flywheel nut with a drill and watch for spark and see what you got.

 

[Conquistador3]

That mysterious black stuff has piqued my curiosity. It could be bits from the intake manifold (it's black rubber on those little Husqvarna and their Poulan and Jonsered relatives): I honestly don't think any appreciably large bit of fuel line can make it pass the carburetor if the strainer screen is still in place. So can you take off the carb adapter plate and check the intake manifold behind it? Just be careful not to lose the tiny impulse pipe there.

I suspect your saw may be yet another victim of oxygenated fuel but we need to find out what has melted away, and can be more than a single thing unfortunately.

 

[hardhat]

Agree that black chunks have to be on air side and not fuel side. Due to small size of holes in filter and fuel jets.
Intake boot. Air filter. Possibly bits of crank seals or anything else attached to crankcase.

 

[clydesdale6]

When I pulled the plug and cranked, I was satisfied with the quality of the spark, but I will certainly check that again. So, maybe before I go the cheap carb route, I have to pull the whole intake side off? I did pull the exhaust a few times already. The first time a bunch of gas poured out and the cylinder looked fairly clean, nothing remarkable, other than carbon on top of the piston. Would an intake side problem contribute to the flooding?
Thanks.

 

[hardhat]

Gonna go out a limb and say the flooding and the rubber chunks are different problems. Flooding almost has to be fuel side of carb and rubber chunks somewhere in the air pathway (air filter, intake boot, something in crankcase (seals or gaskets; not likely). I don't really know. Just throwing out ideas.

 

[Oldsawnut]

Usually if you have a flooding problem its not seals, impulse, gasket, boot, etc issue. Those all cause air leaks and a lean condition not rich. The metering lever in the carb that was mentioned earlier could be it. Your filter could be totally sealed off or you choke sticking on. You could try your carb at 3/4 or 1/2 on the L jet and 1 on the H just to see if it runs for a bit.. If you are decent at tuning by ear. If it runs the metering lever is just too high. I had saws with similar problems that were still rich at even 1/4 turn out that usually ended up being the metering lever. Like I said could be choke or filter. The black specs are prob not rubber but carbon or crankcase gunk dislodged by swimming in fuel like hardhad said... Possibly varnish from the boot that was made black???? Not sure. Coil was mentioned to and its possible but with gas pouring out of the crankcase prob not. Even if the spark is good it can still be way out of time.. I doubt it but.....

 

[Conquistador3]

As I said I suspect there's more than one thing going wrong in that saw. If not drained promptly oxygenated fuel will do a ton of damage: this board is literally stuffed full with such examples.

Ignition should be relatively easy to test if you have a multimeter that can test resistance. You could probably get away with testing the secondary coil alone: it's the one most likely to fail. Just test resistance between the spring inside the spark plug boot and the metal engine case (short block): it should be in the 2,000-3,000 ohm range. If you get strange readings, the ignition module is a goner. Note that an engine can still start and give a nice big spark even with a malfunctioning secondary ignition coil: it has driven me nuts twice in the past and that's why I don't trust my eyes anymore.

 

[rupedoggy]

No offence to anyone that thinks differently but I will go out on a limb and state "it is not the ignition" ignition timing a remote possibility but not the ignition. Mike

 

[Oldsawnut]

No offence to anyone that thinks differently but I will go out on a limb and state "it is not the ignition" ignition timing a remote possibility but not the ignition. Mike

Pretty sure nobody thinks its the ignition just covering the bases...

 

[clydesdale6]

Ok folks, I could use your help with this again. Since I last posted, I have rebuilt 4 carbs on other pieces of equipment and all have been successful, including one echo handheld blower that I retrieved from someone's trash pile. So, I decided I was ready to look at this saw again. Here are some updates:

With the choke pulled, I pull the cord about 5-7 times, it did not start and the plug was soaked with gas. I could even turn the saw sideways and gas came out of the exhaust. I pulled the plug and let it dry out. I took the carb back out and checked that the gaskets and diaphragms went on correctly. I replaced the main jet. I shot carb cleaner through every orifice. I removed both the high and low needles and swapped them. I looked it up and the part numbers are the same for both needles. I have the L at 1.5 turns and the H at 1.75 turns. The saw will not idle for more than a couple of seconds. I was able to get it to run by holding the throttle down and pulling the cord. That got it running for about 5 seconds at high before it bogged down.

When I first took this thing apart, I had a running saw. But, it ran very poorly. As soon as I really dug into wood it would start to stall and I would have to back out. When I took the carb apart, the inner screen was plugged up. Since going back together, I can't get it to run for more than 5 seconds or so.

With regards to spark. There were quite a few pulls that I did not see a spark today. But, I wasn't pulling with vigor. The moment I gave a decent pull, there seems to be consistent spark. But, I am not fully familiar with the way the ignition works so maybe the idea of hooking a drill to the recoil nut is a good idea. I am not seeing anymore rubber chunks on the spark plug anymore.

I really want to figure out what the hell went wrong with this say. I know it is not a great saw, but, I must say I like the 16 inch bar for some things. Otherwise, I just use the 20 inch on my Stihl 261 c-m.

Thanks for all help.

 

[tug]

I don't have too much time to help you out right now. Got to go to work. But sometimes carbs are more trouble to rebuild than replace. It took me a little while to figure it out. I have used OEM carbs for this saw if you need one. The china one are not always a bad as they sound. I have a mantis tiller that I could not get to run right. Two carb kits later, I put a china one on, runs well. Carb cost about what a walbro kit costs and came with a primer ball. It did hurt my pride a little. If you have saw dust in you fuel screen the fuel filter had failed. If it floods out the needle may not be seating. You may have drawn some debris into an orifice also. Walbro website has diagrams of carbs and how fuel flow that might heip.

 

[clydesdale6]

This was in the carb before rebuild.

 

[tug]

If that was wood chips one of three things happened. Your fuel filter came off, your fuel filter has a hole in it, or there was a hole in the fuel line and unfiltered gas was getting to the carb.
That screen is the last effort to keep debris out of the carb orifices. The symptoms are usually the saw starts and idles but bogs down and dies when you rev it up.
When you are describing rubber debris on your plug are you sure it is not carbon. If you soak a parts in fuel that have a lot of carbon deposits on them in fuel the carbon will break up into chunks.

The easiest way to diagnose a saw is if you can break each system and part into its own function. If you think it is the carb but have not ruled it out and start monkeying with the ignition this never ends.That is why having the ability to just change out parts makes this easier.
When it died last time was the plug wet?
Pull your plug make sure all the fuel is out of the cylinder and bottom end of the saw. Disconnect the fuel line from the carb, put a little bit of fuel in the spark plug hole. Put the plug back in see if it will start. You can also squirt a little fuel in the the carb venturi as an alternative. The saw will only idle and die, this will help rule out the ignition.
I always seat the needles counting how many turns out it was and then write it down. If you want I can check what the needles are set at on the carbs that I have for this saw.

 

[clydesdale6]

Thanks. The fuel line cracked at the top of the fuel filter. As I recall, it was barely connected. That is what prompted the whole repair and since I had to take the carb out to get to the fuel line, I figured I would just rebuild it since it has been over 15 years. When I removed the needles, I too counted and wrote it down. I put them back in the same number of turns. I know those original settings, but have also tried others.

When I started it with the throttle wide open, it would run for about 5 seconds. I am pretty certain the plug was then dry. But, if I pull the recoil for 5-7 times and it does not start, tipping the saw results in gas draining from the exhaust and the plug is soaked.

I am thinking it may have been carbon chunks at this point, but they were soft. I am not getting anymore of those chunks. I will give this thing another shot later today, but it does sound like I may put a cheap carb on to help diagnose. What do you think of the possibility of it being an air leak, like the impulse tube that I have heard about? Thanks.

 

[Old2stroke]

Maybe I missed it but have you done a pressure test on the carb? It sounds like your whole problem is flooding due to a simple carb fault that is causing the inlet valve to not be seated. Could be the tip of the inlet valve and it's seat have to be cleaned or the control lever is set too high or the fuel control diaphragm has a button that wasn't hooked into the control lever. There aren't too many things that cause flooding this serious and should be one of the easiest faults to cure.

 

[clydesdale6]

Maybe I missed it but have you done a pressure test on the carb? It sounds like your whole problem is flooding due to a simple carb fault that is causing the inlet valve to not be seated. Could be the tip of the inlet valve and it's seat have to be cleaned or the control lever is set too high or the fuel control diaphragm has a button that wasn't hooked into the control lever. There aren't too many things that cause flooding this serious and should be one of the easiest faults to cure.

I didn't formally pressure test, but I hooked clean fuel line to the carb and blew into it. I held that unknown pressure and then had someone push the metering lever down and heard the air rush out. I used the walbro "w" tool and it clears the lever. I agree that this should be easier to figure out, but no luck. I put a new inlet needle in too.
Any chance the impulse pipe could cause this? Thanks.

 

[Old2stroke]

Any chance the impulse pipe could cause this?

Very unlikely but you could verify this by suckin on he impulse port. Should hold a vacuum. Other causes might be (unlikely) welch plugs that are leaking very badly and allowing fuel to bypass the metering screws. Is it possible that it is acting flooded because the crankcase still has too much residual fuel in it from a previous flooding? Try cleaning the engine right out by removing the fuel line or plugging it, then remove the plug and with the ignition switch off, hold the saw so that the spark plug hole is at the lowest point and pull the engine over vigorously until nothing sprays out the plug hole. Once the engine is cleaned out, stick a clean dry plug in and pull it over again with the ignition on. If it was flooded it may fire and even run briefly after a few pulls. Pull the plug and if it is wet again, you have to repeat cleaning the plug and trying to restart. After a number of firing attempts, the plug should come out dry, NOW you know the engine is no longer flooded and you can hook the fuel line back up and try a normal start. Are you clear about getting the choke off as soon as it tries to fire?
One other thing, I'm not familiar with that saw but is the fuel tank part of the crankcase body and might have a bad gasket allowing fuel to get directly into the crankcase? Not an issue if there is a plastic tank or the engine is a clamshell design.

 

[irhunter]

I have the L at 1.5 turns and the H at 1.75 turns. The saw will not idle for more than a couple of seconds.

FWIW, this is from the 36/41 owner's manual:

"The basic setting can vary
between: H= 2-1/8 to 2-7/8 turn respectively L= l-1/2 to 2-1/4 turn."

The 136/141 owner's manual doesn't list carb settings. I think I'd try setting the carb to the middle of the basic range, and see if that changes anything. Otherwise, it seems you may be close to needing to try an AM carb.

Roy

 

[clydesdale6]

FWIW, this is from the 36/41 owner's manual:

"The basic setting can vary
between: H= 2-1/8 to 2-7/8 turn respectively L= l-1/2 to 2-1/4 turn."

The 136/141 owner's manual doesn't list carb settings. I think I'd try setting the carb to the middle of the basic range, and see if that changes anything. Otherwise, it seems you may be close to needing to try an AM carb.

Roy

Thanks. I will definitely try turning the screws out more and give that a shot.