2001 Husqvarna 350 (49cc) Chainsaw - Rebuilt, won't start

[koriley]

I have a 2001 Husqvarna 350 (49cc) chainsaw non-EPA. Still will not start. Everything is new from the crank up (cylinder assembly kit w/ piston, ring, bearing, all gaskets; new carburetor, manifold partition & boot, impulse hose, intake flange; new coil, plug, fuel line & filter, fresh 2-cycle, etc., etc., etc.).

Purchased a new compression tester for $40 from O'Reilly's Auto Parts - Had less than 30 psi after 6 pulls prior to rebuild; now only have 60-90 psi after same attempts. Thumb over spark plug hole and definitely has a lot of compression.....not sure if compression tester could be bad.

Regardless, unit will not start after confirmed spark & fuel, sitting overnight with plug out, etc. I have more in this chainsaw than purchasing new, simply trying to learn something as I like to tinker, and knowledge costs money. Took my time with re-assembly, and watched YouTube video's, so I'm 95% sure I did everything right.

Almost ready to disassemble and part out, but it seems like something small that I'm missing. Have tried to start with the brake on/off, decompression valve in/out, everything. Any input is greatly appreciated.

P.S.) Will check new decompression valve tonight.

Kelly

 

[juttree]

Posting this over in the chainsaw forum will get you more responses. Did you try putting some mix directly into the carb? A little trick I like to do is putting a little splash of 2 cycle oil into the spark plug hole then trying to fire it up, you wouldn't believe some of the old saws I've resurrected that way. Not mix, just oil. Give it a shot and let me know what happens. Good luck

 

[koriley]

I pulled new carb & muffler off tonight. Put old carb back on and left muffler off. Muffler had quite a bit of fuel mixture sitting within. Finally got saw to pop and stay running, although roughly. Takes at least 8-10 pulls to fire, even after warmed up. Am going to put new carb back on and try to adjust mixture once complete. Seemed like it wanted to run.......I did put a little straight 2 cycle in cylinder prior.

Thanks for your response/advice/help. Kelly

 

[juttree]

How is your spark plug, is the gap correct?

 

[juttree]

Another thing to check would be your coil to flywheel gap. Personally I just use a business card, put it between the magnet and coil, lossen the coil screws to let it snap closed then tighten the screws back up and remove the card. Just rotate the flywheel to make sure nothing is hitting and you should be all set. Sorry if you already know this, just figured I'd mention it.

 

[koriley]

Thank you......I have 3 brand new plugs (NGK BPMR 7A's @ 0,02"), swapped them all out and rechecked the gap on the flywheel. I put the new carb back on and it did pop several times, but would never start (as compared to the old carb that would at least rough idle). For my own sanity, I tore the saw down again tonight to ensure I don't have any leaks, most notably around the manifold partition/intake manifold rubber boot. These seem to go on much better and hold when attached to the Cylinder (prior to bolting down the cylinder itself).

The good news is, I am much more optimistic now that it at least ran with the old carb @ rough idle. Am getting pretty good/quick at tearing down and putting back together. I'm going to let everything dry out overnight and put back together tomorrow evening. I found below link to be extremely helping for a novice.



Thanks again for all your help. I'll repost once I get it back together.

Best regards, Kelly

 

[juttree]

Your welcome and good luck.

Justin

 

[koriley]

Quick question - is there any particular way or direction that the ring should be situated around the piston? Am asking because I had initially installed it with the break or opening toward the back, or carburetor, side of the engine (opposite the arrow/exhaust side). Knowing that once the piston is installed within the cylinder the gap on the ring pretty much closes.

As a side note, the old carburetor (again, ran, but very rough) was the original Walbro HDA 159 A (P/N# 503281614) that came with the chainsaw when purchased new in 2001. I replaced it with a Zama C3-EL18.....not sure if that's good or bad - it bolted right up and popped a few times but would never run.

Thanks again for all the help, Kelly

 

[juttree]

Quick question - is there any particular way or direction that the ring should be situated around the piston? Am asking because I had initially installed it with the break or opening toward the back, or carburetor, side of the engine (opposite the arrow/exhaust side). Knowing that once the piston is installed within the cylinder the gap on the ring pretty much closes.

As a side note, the old carburetor (again, ran, but very rough) was the original Walbro HDA 159 A (P/N# 503281614) that came with the chainsaw when purchased new in 2001. I replaced it with a Zama C3-EL18.....not sure if that's good or bad - it bolted right up and popped a few times but would never run.

Thanks again for all the help, Kelly

The ring should be installed with the opening around the locator pin (small pin inside the ring grove). With the carb you should remove the limiter caps and start with the factory settings (usually one turn out with the high and low)

 

[juttree]

Most pistons but not all, have an arrow on the top which should be pointing to the exhaust. The ring opening should be towards the intake side.

 

[HuskStihl]

I didn't watch the video, but did you replace the crank seals? They are notorious for leaking, which can cause these issues