Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: wbhburn on October 19, 2013, 12:23:26 pm

Title: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 19, 2013, 12:23:26 pm
20 yr old Husky 359 piston seized and I replaced it and cylinder with no parts left over :-). Tried to start afterward but wouldn't fire despite having spark and fuel flowing out the line when removed to check. Watched a U-tube on the repair and realized I should have paid more attention to intake manifold and carb installation. Removed and reinstalled both. Still no fire even with a whiff of starting fluid. What could it be? I'm not a 2 cycle guy so I don't understand the principals. What's the tube on the manifold for (impulse, what's that?)? Anyway I could blow through it. Rubber manifold didn't seem to have cracks or leaks. Made sure the band was fastened. I tried to ensure the little stub (orifice) on the manifold was fully engaged in it's counterpart on the intake port but when I felt inside the assembly it was smooth except on the bottom where the stub should mate (it was slightly raised there). That assembly not being properly seated is all I can think of, should it feel perfectly smooth all around the inside of that throat?

Help?

Bill
Title: Re: Replaced piston/cylinder now won't fire
Post by: Cut4fun on October 19, 2013, 12:37:35 pm
Welcome.  Are you sure you want your email as your username?  Can shorten for you to wbhburn


Also put some mix into a squirt can or bottle. Use that to prime, not ether starting fluid.


Are you getting spark?  on/off is on.  Just asking cause you never know. Did it before myself.
Title: Re: Replaced piston/cylinder now won't fire
Post by: jmester on October 19, 2013, 12:43:43 pm
Is the spark plug moist at all? And did you figure out why the last piston and cylinder went bad
Title: Re: Replaced piston/cylinder now won't fire
Post by: 660magnum on October 19, 2013, 12:46:09 pm
did those old 359'shave the plastic boot clamp?
Title: Re: Replaced piston/cylinder now won't fire
Post by: Cut4fun . on October 19, 2013, 01:01:19 pm
Old 359 had that plastic clamp.  If you didnt update that you need to.  Probably what fried it to begin with.
Title: Re: Replaced piston/cylinder now won't fire
Post by: 660magnum on October 19, 2013, 01:38:21 pm
There's another situation with that line of saws is that the threads strip out of the carb end of the boot real easy if you are heavy handed.
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 19, 2013, 02:03:17 pm
Wow, what great response already!

Cut4Fun- Squirt bottle; got it!, Spark; yes, Update plastic; will do after this weekend but like to get it running first.

Jason - Plug not moist, don't know why is seized. running along fine at high rev in middle cut and stopped on a dime. No other symptoms.

660mgnum - Plastic boot retainer; yes, threads not stripped (yet).

All, what's with the little hose on the manifold? What's impulse?
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 19, 2013, 02:10:02 pm
Oh yeah. Please address this question...

the only concern I had when reassembling was the "lump in the throat" of the intake. After putting on the manifold, I felt around inside the joint with my finger and it was smooth and apparently mating well except at the bottom (just above where that little projection on the manifold is supposed to go into the indentation on the port). It was raised slightly there. Could that be the problem? There is a small orifice on that protrusion that connects with the little tube thing. Could that not being seated properly cause the problem?
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 19, 2013, 02:59:00 pm
I took it apart again and ensured the manifold was properly seated against the I-port. Also noticed the cyl. gasket is directional. Don't know it was backwards the first time but made sure the notch was in the rear. Hoping that was the problem but STILL WON'T FIRE AT ALL. :'( BTW, I'm getting pretty good at removing the cylinder.
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 19, 2013, 03:16:20 pm
Yes, please do shorten. I tried but couldn't figure it out. Can it only be done from admin end?
Title: Re: Replaced piston/cylinder now won't fire
Post by: jmester on October 19, 2013, 03:20:13 pm
The small line should be the impulse line and it should run from the crankcase to the carb flange or the pump side of the carb. Try to remove the spark plug and put some fuel in and try it out. With the spark plug not moist sounds like a fuel problem to me. Do you pressure/vacuum check the crankcase. Is your spark threw a tester or the plug grounded on the cylinder. My be a bad plug.
Title: Re: Replaced piston/cylinder now won't fire
Post by: Cut4fun . on October 19, 2013, 03:25:33 pm
username fixed.

husqvarna 359 IPL   http://www.husqvarna.com/ddoc/HUSI/HUSI2004_AAaa/HUSI2004_AAaa__1062606-64.pdf
Title: Re: Replaced piston/cylinder now won't fire
Post by: Cut4fun . on October 19, 2013, 03:26:59 pm
Service Bulletin for 357XP, 359, 353, 346XP 350
This service bulletin is not new. I thought that there might be some out there who were not aware of it so here it is. If your saw has a black plastic clamp around the intake right next to the cylinder it is applicable to it. If the clamp is of steel construction then you should be ok.

B0600023
SERVICE

*537 43 88-01*
*compl 537 25 13-02
English 1 (1)

SB, 357 XP, 359, 353, 346 XP,
Partition wall and clamp for intake system,
2006-03

The existing intake system on 357XP, 359,353 and 346XP currently consists of an integrated plastic clamp in the partition wall. As the clamp is made of plastic, there is a risk of deformation. This results in impaired clamping force against the cylinder, which in turn can result in leakage in the intake system. To prevent this from occurring, we have now introduced a metal clamp and a new partition wall.

The new partition wall is made up of polyamide with 30 % fibre glass.
The new clamp is a hardened steel clamp. The new material and the design of the clamp reduce the risk of deformation and the subsequent risk of leakage.

Full replaceability prevails.
Introduced from serial number:
357XP 061100201
359 061100001
353 061100001
346XP 061100001

New part no. Description Excl. part. no. Remark
537 25 13-02 Partition wall, intake, complete New spare part
537 43 88-01 Clamp, intake New spare part

Spare part, partition wall, part number 537 25 13-01, has been discontinued and is replaced by part number 537 25 13-02.
Title: Re: Replaced piston/cylinder now won't fire
Post by: Cut4fun . on October 19, 2013, 03:28:34 pm
Service Bulletin 357 XP, 359, Introduction of new carburetor for better idling stability,
2008-10

To achieve better idling quality, a new carburetor has been introduced in the production. The new name of the carburetor is Zama C3-EL42, replacing Walbro HDA199A/B and HDA191A.

New part number for the carb is 505203001.

Also, requires a different flange, part number 503928502.

Introduced from serial numbers:
357XP 083800001
359 084500001
Title: Re: Replaced piston/cylinder now won't fire
Post by: Cut4fun . on October 19, 2013, 03:38:13 pm
IF you dont want to buy new updated parts listed above post and yours is still usable.
Do the below mod. Use a older husky 372 metal intake clamp IMO.  I think the newer strato 372 intake clamp may be bigger??? thats why I say the old school 372 clamp.

359 intake fix
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 19, 2013, 03:50:03 pm
Did not check vacuum or pressure in crank case. Don't know how or where. Grounded testing only on spark plug. My question though is why would any of this change if I didn't fool with it? Someone on another forum suggested CC vacuum leak also. Is there instructions for this some where?

BTW thanks for all the attention. I need to get this running while I still have a chance to cut firewood for my heat.
Title: Re: Replaced piston/cylinder now won't fire
Post by: sharkey on October 19, 2013, 06:49:03 pm
Basically you need to find out why the cylinder failed in the first place.  Was it drawing air somewhere?  How you find out is to pressure test the case.  You can buy a pump, you can set your compressor regulator down to 5psi, or you can go up to the drug store and buy a big horse syringe.  You dont need the needle, just need the end of the plastic syringe to fit your impulse hose.  Impulse is the alternating suction and pressure wave that is piped off from below the piston crown in the crankcase, and it is used to run the carb's fuel pump. 

To do the test you will need two rubber strips.  If you have an old inner tube cut a couple strips out of it 3 inches long by an 1 1/4 wide.  Place one rubber strip between the muffler and the cylinder, and the other between the carb and the cylinder.  Bolt the carb and muffler back into place crushing the rubber strip to create a seal.

Now take your horse syringe and plug it into that impulse hose.  Put a little air pressure into the case and use some windex or soapy water to find the leaks.  Common leaks are found at the crank seals, where the cylinder bolts to the case and where the carb attaches to the intake.  Make sure the spark plug is tight.       
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 19, 2013, 09:02:15 pm
So I'll need to remove the handle/tank to get to the crank seams right? 
Title: Re: Replaced piston/cylinder now won't fire
Post by: 660magnum on October 19, 2013, 09:08:57 pm
If you have a leak and can not find it elsewhere?
Title: Re: Replaced piston/cylinder now won't fire
Post by: Moodys Modded Saws on October 20, 2013, 01:01:56 pm
The fix on the HDA carb is pretty simple. Whether it's failed or not get rid of the plastic boot clamp. T8 safety bit and be sure that the transfer caps are tight.
Title: Re: Replaced piston/cylinder now won't fire
Post by: Adirondackstihl on October 20, 2013, 08:49:36 pm
So I'll need to remove the handle/tank to get to the crank seams right? 
No. But you will need to remove the flywheel and clutch t actually see any bubbling from the seals. Removing the flywheel....no problem. Removing the clutch may cause you some difficultly without the $8 removal socket.

Where are you from? Ship the saw to me if you want......I'll get it running. Or perhaps someone lives close to you that could lend a hand?
Title: Re: Replaced piston/cylinder now won't fire
Post by: sharkey on October 21, 2013, 12:40:25 am
So I'll need to remove the handle/tank to get to the crank seams right? 
The crank seals are behind the clutch and behind the flywheel.  Use a piece of rope down through the spark plug hole to lock down the crank so you can turn the nuts.  Remove the clutch by reverse thread meaning it turns clockwise to loosen.  On the flywheel side, loosen the flywheel nut but dont take it all the way off the crank.  Use a soft hammer and tap the nut at the top of the crank threads (to protect them) and off pops the flywheel.         
Title: Re: Replaced piston/cylinder now won't fire
Post by: Spike60 on October 21, 2013, 07:08:51 am
Even with most of the carb/intake/seal issues that are being discussed, the saw should fire on a squirt of fuel if it has compression and spark.

Even if there is a visual spark, the coil could still be bad. It could be weak on reserve voltage or firing out of time.  Often this can be detected by weak pop that sounds like the deco is locked open.
Title: Re: Replaced piston/cylinder now won't fire
Post by: KilliansRedLeo on October 24, 2013, 05:59:16 am
Spike60 is correct, are you sure the coil is grounded properly?
Title: Re: Replaced piston/cylinder now won't fire
Post by: jmester on October 24, 2013, 09:10:44 pm
Is the plug getting any fuel. Spark is great, but no fuel means not going to run.
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 26, 2013, 01:39:49 pm
I removed everything required to do the vacuum test but I did not have enough hands to hold the saw, reach the impulse tube, pump in the air from the syringe and check for leaks at the same time. However, I did a very close inspection and saw no areas around the case gasket that could be leaking. I "orally" checked the I manifold and determined it held pressure (no leaks). Reassembled and still no fire. Spark looks good and strong. Questions...

Even if there is a pin hole leak somewhere in the case wouldn't it at least fire?
How can I "prime the thing" just to get it to fire once?
Do I add a bit of gas in the carb throat or in the plug hole? I just want to hear it fire once :-)
I'm willing to up-grade to the new carb and manifold Cut4fun suggested. Where to purchase?
If it was running before could the old carb/manifold really be the problem?
Title: Re: Replaced piston/cylinder now won't fire
Post by: 660magnum on October 26, 2013, 02:14:16 pm
A two stroke engine with an open seal (or no crankcase vacuum/pressure) If primed in the spark plug hole, should "POP" every time you pull it over but never actually start and run. The same goes for a reed valve two stroke with a bad reed or a engine with a closed carb butterfly.
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 26, 2013, 02:24:49 pm
No "Pop"

I have a VOM. Can I use it to check coil output?
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 26, 2013, 02:27:02 pm
Oh, and how about timing?
Could these things have changed after piston/cylinder replacement?
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 26, 2013, 02:34:18 pm
Before I forget - thanks to all for the attention

So, now that I think about it, here's the logic as I see it. PLEASE correct me if I'm wrong....

a) Even with a vacuum leak I should get some bang or pop with a bit of fuel manually applied.
b) In the absence of that indication, one could assume an electrical problem
c) My focus should be on electrical and all the other possibilities would be secondary until I get some fire after prime

As I asked before, how to trouble shoot electrical (and please don't assume I know ANYTHING)? Step by step if you have the patience. Again, I do know how to use my Fluke VOM, will that help?
Title: Re: Replaced piston/cylinder now won't fire
Post by: jmester on October 26, 2013, 02:56:10 pm
First I would check all your wiring to make sure there are no bare spots that would cause a ground. Or a broken wire. Then I would check to make sure the spring that attaches to the spark plug is ok. Then I would check my coil to flywheel gap. Before all that I would try another plug and see if it is just the plug,just because it is new does not mean that it is good. Look for any blue color on the flywheel and the coil as these usually mean one or both could be bad. Hope this helps a little.
Title: Re: Replaced piston/cylinder now won't fire
Post by: jmester on October 26, 2013, 03:00:35 pm
Also if you had spark before you should not lose it. By replacing the cylinder unless you pinched or cut the wire. I still think if your plug is not wet with fuel you have a fuel related problem. Have you done anything to the carb, is the impulse hose connected?
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 26, 2013, 08:47:11 pm
Done nothing intentional to the carb. However, after having disassembled the thing three times who knows about unintentional?

When it locked up initially, it was literally "Smoke'n hot". Could something have overheated like the coil? What kind of ohms should the coil read - with leads from where to where? sp 
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 26, 2013, 11:30:36 pm
The more I think about it the more I realize that as hot as it got, anything plastic or rubber close to the head could be messed up (like the manifold), though the impulse line was not impeded.
Title: Re: Replaced piston/cylinder now won't fire
Post by: mountainlake on October 27, 2013, 06:21:54 am
The small line should be the impulse line and it should run from the crankcase to the carb flange or the pump side of the carb. Try to remove the spark plug and put some fuel in and try it out. With the spark plug not moist sounds like a fuel problem to me. Do you pressure/vacuum check the crankcase. Is your spark threw a tester or the plug grounded on the cylinder. My be a bad plug.

 Yes,  If you haven't tried a new plug and dumped some mix down the plug hole do that first.  Keep in mind when you dump fuel down the cylinder it will take quite a few pulls on fast idle (put the choke on then back off should get it on fast idle) or with the throttle held open to get it to fire.  If it fires and then stops go over the carb again or get a new one making sure you don't have the impulse line blocked off with the carb gasket.  One other thing is your piston the right one for the cylinder, don't think a open port piston will run with a closed port cylinder  Steve
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 27, 2013, 12:33:11 pm
Just tried the starting suggestion from Mountainlake including a new plug. No go. However the pressure release did kick out a couple of times during the process. I'm thinking a new manifold may be the nest thing.
Title: Re: Replaced piston/cylinder now won't fire
Post by: mountainlake on October 27, 2013, 01:38:53 pm

 Did you check your compression after the rebuild, if too low it won't start.  Steve
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on October 27, 2013, 03:56:04 pm
No, will do!
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on December 01, 2013, 10:47:33 pm
Checked compression with a automotive tester. Could only get it to 95 lbs after lots of pulls. What does that mean? Sounds low to me. Why would that be with a new piston/head. I scored it slightly installing initially but would that do it? Can hardly see it.
Title: Re: Replaced piston/cylinder now won't fire
Post by: Cut4fun . on December 01, 2013, 10:53:54 pm
No adapters needed that are shown. Valve in end. Just screw in tght with o-ring seal. Pull till psi quits climbing.  http://www.walmart.com/ip/Equus-3612-Innova-Compression-Tester/14644667
Title: Re: Replaced piston/cylinder now won't fire
Post by: 3000 FPS on December 02, 2013, 11:21:55 pm
Checked compression with a automotive tester. Could only get it to 95 lbs after lots of pulls. What does that mean? Sounds low to me. Why would that be with a new piston/head. I scored it slightly installing initially but would that do it? Can hardly see it.

I can tell you this if you get a good compression reading and you only have 95 psi then that saw is not going to start.  It is not enough compression.   

Make sure the de-compression valve is out before trying the compression test.
Title: Re: Replaced piston/cylinder now won't fire
Post by: farmboy on December 03, 2013, 08:46:06 am
Decomp in got me the other day.  Bumfuzzeled for a min.  Talked ugly to myself for a few.
Shep
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on December 07, 2013, 01:59:20 pm
A bumfuzzled, ugly self-talker; must have been a sight to behold!
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on December 07, 2013, 02:22:11 pm
So, 95lbs won't get it huh? Pretty sure I had decomp out but I'll do the test again (8 mile trip to town to borrow from Autozone) just to be certain. But let's assume 95 is the correct reading. What then? How can that be with a new piston/cylinder?
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on December 07, 2013, 04:03:32 pm
Did second C test with another tester and still got just under 95. Can anyone tell me how this can be?
Title: Re: Replaced piston/cylinder now won't fire
Post by: 3000 FPS on December 07, 2013, 09:46:40 pm
If it were me I would check the squish on the saw at this point to make sure what you installed are the correct parts.   

You remove the spark plug, then take a piece of solder like you would use for soldering electrical things, and then put the solder through the spark plug hole and bend it so that it touches the cylinder wall.   You want to have the solder facing out toward the sides of the saw and not from front to back.   Then grab the flywheel with your hand and crank it over until is smashes the solder.  Then back it up to smash it again.   
Remove the solder and then measure the very end of it to see how much room there is between the cylinder top and the piston top.   It could be let say some where around .050"s to .035"s.   If there is an excessive amount it will make the compression low and could be the wrong piston.   But you have to measure it to see.
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on December 10, 2013, 08:56:59 pm
Squish test....Check. It came out right at .05 but I'm sure it was less than that since I couldn't get it to go past TDC.

Was the compression check valid with fairly dry cylinder walls?
Title: Re: Replaced piston/cylinder now won't fire
Post by: jmester on December 10, 2013, 09:50:17 pm
You did put oil on the piston and cylinder before you, reassembled the engine? Use a smaller size solder like for electrical work . Plumming solder is to thick. The engine needs to go full circle to get a correct reading of the squish.
Title: Re: Replaced piston/cylinder now won't fire
Post by: 3000 FPS on December 10, 2013, 10:01:39 pm
Also if the squish does check ok, then you are going to have to pull the cylinder off so that you can make a visual inspection of the piston and cylinder.
Title: Re: Replaced piston/cylinder now won't fire
Post by: Adirondackstihl on December 11, 2013, 11:44:35 am
How can that be with a new piston/cylinder?

New rings?
Scored cylinder?
Faulty decomp? ( that's where my $ is at )
Title: Re: Replaced piston/cylinder now won't fire
Post by: sharkey on December 15, 2013, 03:32:52 am
I heard of some aftermarket kits that were supplied with in-correct rings.  They were too small.  I would think you would notice this putting them on, but maybe they were pretty close and only the gap was off?  When you take your cylinder back off, slip the rings into the cylinder without the piston and see what the gap looks like.     
Title: Re: Replaced piston/cylinder now won't fire
Post by: danders on January 07, 2014, 01:40:24 pm
Did this ever get resolved?  Checking the ring end gap seems like a good idea. Also, since the piston was replaced is there any chance it went in backwards? I would guess that you would have run into problems with the ring ends hanging up in the exhaust port if that was the case so it seems pretty unlikely.
Title: Re: Replaced piston/cylinder now won't fire
Post by: Ljute on January 11, 2014, 09:46:12 am
Will we ever hear the conclusion? My money's on a wrong piston.
Title: Re: Replaced piston/cylinder now won't fire
Post by: 3000 FPS on January 11, 2014, 11:56:37 am
Will we ever hear the conclusion? My money's on a wrong piston.


I was kinda of leaning that way myself.
Title: Re: Replaced piston/cylinder now won't fire
Post by: wbhburn on February 09, 2014, 05:37:39 pm
No positive resolution yet. Thanks for your concern.

As I was taking some pictures of the cylinder to post, I looked closely at the ring to see how it fit when completely compressed. I noticed it did not close completely and on even closer inspection realized that part if the end was broken off. The ends did not meet at all. Don't know when that happened but -MIGHT THAT BE A SOURCE OF COMPRESSION LOSS?  :'(

Furthermore, on my first attempt to get the cylinder over the piston I think I both slightly damaged the piston and scored the head. Between all those errors, I'm sure it's not sealing properly. Better start over with a new piston/cylinder.

Now, does anyone have an old 361-371 class saw for sale? Is $200 - $350 a reasonable price?