Husqvarna 350 rebuild won't run

[cbazq271]

OK, I just finished putting a new AM 346xp topend on my 350. The saw needed a new topend because someone put straight gas through it. The 346xp kit was a nice quality kit. First I took the saw all apart ( minus pulling the crank out ) and cleaned and inspected it. Put a new topend on it, new carb, all new intake pieces, new fuel line, fuel and air filters, also checked the fuel tank vent, which is ok. I tested the spark which is good and strong, has 110-120 lbs of compression, pulled the flywheel to see it has moved out of time, and it was fine. Saw will not start no matter what. It sounds nice and strong put will not fire, will pop once, in about 15 pulls , but will not start. Its got Spark, Compression, fuel, but won't start. I know its getting fuel, because the plug is wet went I remove it, and if I pull on it for awhile gas will come out the muffler. I have removed the stops on the carb jets also. I can't think why this saw won't run. It wont even fire with starting fluid. Any ideas? Thanks, Chad

 

[Dan_IN_MN]

Did you do a vac and psi test and leave the exhaust sealed up? Sounds like my Jonsereds 49sp did when I forgot to remove the rubber seal from the exhaust.

110-120 is kind of low on the compression numbers for a new top end. Did you check squish?

OH....starting fluid is a GREAT degreaser/oil remover. fyi hint.....hint,.....

It does sound like it's flooded. Pull the plug, hold the throttle wide open and pull it over several times. Put the plug back in, hold throttle wide open and pull like you mean it. It should sputter to life. Liquid gas will not burn. A two stroke will not run with liquid fuel in the crankcase.

 

[woodyman]

OK, I just finished putting a new AM 346xp topend on my 350. The saw needed a new topend because someone put straight gas through it. The 346xp kit was a nice quality kit. First I took the saw all apart ( minus pulling the crank out ) and cleaned and inspected it. Put a new topend on it, new carb, all new intake pieces, new fuel line, fuel and air filters, also checked the fuel tank vent, which is ok. I tested the spark which is good and strong, has 110-120 lbs of compression, pulled the flywheel to see it has moved out of time, and it was fine. Saw will not start no matter what. It sounds nice and strong put will not fire, will pop once, in about 15 pulls , but will not start. Its got Spark, Compression, fuel, but won't start. I know its getting fuel, because the plug is wet went I remove it, and if I pull on it for awhile gas will come out the muffler. I have removed the stops on the carb jets also. I can't think why this saw won't run. It wont even fire with starting fluid. Any ideas? Thanks, Chad

After you get everything dried out and it still floods and won't start I would pull the carb and check the level on the needle,check all your work to.Set your H & L about 1 1/4 turns out to start with and go from there. If you get it running check the squish and get it down to at least .020,.023 you need more compression.When working on a saw it's nice to know why it did what it did.Hope you get it going friend.

 

[blsnelling]

IF you're using the right kind of guage, and pulling until it won't go any higher, Then 110-120 PSI is VERY low compression!

 

[TraditionalTool]

IF you're using the right kind of guage, and pulling until it won't go any higher, Then 110-120 PSI is VERY low compression!

It would seem so if a new 346 top end was installed, and presumably a new ring. Those numbers seem really low and should be more like 150, at LEAST!

 

[o8f150]

IF you're using the right kind of guage, and pulling until it won't go any higher, Then 110-120 PSI is VERY low compression!

:agree2::agree2: it should be blowing at least 150 or better

 

[cbazq271]

Thanks for the tips. I will try a different compression tester and see what that reads. I tried to get this saw running without the base gasket, (using sealent) first, Thinking it would give it a better squish. Then when I started having all the problems, I put the base gasket in, thinking it my have to tight of a squish. If I can't get it running, I will just sell it, to get some of my money back and buy a new saw. Which sucks because I really like the 350 style better then the 450, and I can't justify buying a new 346xp. I will let everyone know what I find with the different compression gauge. Thanks

 

[nmurph]

Pull the plug and pull the starter rope 30 times. Then leave it standing without the plug overnight. Tomorrow, dribble a few drops of mix down the carb, pull the throttle open and pull the starter rope slowly to let the mix into the cylinder. Then pull it a couple of times to start it. If it pops, then you have carb problems or you flooded it (my bet). Report back with your findings.

 

[dsell]

You will have to do a pressure test to see how many places it is leaking. Do you need help with that? It has to be done. Does it have a decompression valve? If so, it will leak, the sparkplug, the intake, the cylinder gasket, the cranks seals might be leaking, but I would just about guarantee the plastic to crankcase is leaking bad. Have you tried a different plug? Keep in mind, the coil gets its common connection through a thin piece of brass from the cylinder base bolt since the coil is mounted to plastic. Have you tried removing the kill switch wire from the coil? 110 is way too low on compression and we're all curious why. You may have to tell us where you got this high quality kit so we can avoid it.

 

[nmurph]

Thanks for the tips. I will try a different compression tester and see what that reads. I tried to get this saw running without the base gasket, (using sealent) first, Thinking it would give it a better squish. Then when I started having all the problems, I put the base gasket in, thinking it my have to tight of a squish. If I can't get it running, I will just sell it, to get some of my money back and buy a new saw. Which sucks because I really like the 350 style better then the 450, and I can't justify buying a new 346xp. I will let everyone know what I find with the different compression gauge. Thanks

If you want to move it, I'm all ears. Shoot me a PM.

 

[Dan_IN_MN]

By chance did the ring get broken during install? I don't know if a broken ring would build 120psi.

 

[Axlerod74]

What spark plug are you using?

 

[tbone75]

Just sounds like the compression is to low? I would check the decomp for a start. I have put 5 - 350s together with AM P&C or just piston.They all run about 140-150 compression without a base gasket.

 

[Homelite410]

Did you have throttle wide open for compression test?

 

[watsonr]

Did you have throttle wide open for compression test?

It doesn't matter, the combustion chamber is exposed when the piston is below the exhaust anyway and will fill it every stroke unless the saw is running.

 

[nmurph]

I know its getting fuel, because the plug is wet went I remove it, and if I pull on it for awhile gas will come out the muffler. I have removed the stops on the carb jets also. I can't think why this saw won't run. It wont even fire with starting fluid. Any ideas? Thanks, Chad

Guy's, here's your clue...it's flooded. The plug may be bad, or it may have a bad coil, or a broken ring, but most likely it just has too much fuel bc of improper carb settings or starting techniques.

Cbaz, how did you check the compression? You should pull it until it stops climbing. The position of the throttle is of no consequence to the final number. You might reach that number a couple of pulls faster with the throttle open, but there is enough air pulled into the saw with the movement of the piston. If you are getting a maximum of 110 psi the saw should run. It may not run strongly, but it will have enough compression to fire and run. You also need to have the H & L needles at 1 turn from lightly seated. I would pull the plug and pull the starter rope 30x's with the plug out. Insert a new plug and try it.

 

[timmcat]

If the saw was seized due to straight gas then the lower end bearings could have gotten fried from lack of oil and caused the crank seals to get brittle and fail. Bad crank seals if they are really bad will cause the flooding and soaked plug as well.

 

[woodyman]

Guy's, here's your clue...it's flooded. The plug may be bad, or it may have a bad coil, or a broken ring, but most likely it just has too much fuel bc of improper carb settings or starting techniques.

Chad, how did you check the compression? You should pull it until it stops climbing. The position of the throttle is of no consequence to the final number. You might reach that number a couple of pulls faster with the throttle open, but there is enough air pulled into the saw with the movement of the piston. If you are getting a maximum of 110 psi the saw should run. It may not run strongly, but it will have enough compression to fire and run. You also need to have the H & L needles at 1 turn from lightly seated. I would pull the plug and pull the starter rope 30x's with the plug out. Insert a new plug and try it.

Thats what you should do.The OP also said he put a new carb on which are not always set right.On a saw that floods it's the fuel delivery or plug most of the time if it's getting good spark.

 

[cbazq271]

Redid a compression test with a high end Snap-on tester, that I know works. Its the gauge I use when I work on my race snowmobile and quads. Only got 130lb max. Did three test back to back with the same result. Let the saw sit over night and still won't start and when I pull the plug out the plug is wet . I have the carb set at 1.25 turns out from setted. I did a visual check of the crank seals ( without removing them ) and they look finr. I know they can look good and still leak, but I would think with the good spark, fuel and compression, it should at least pop and few times. I know the engine was put together right, no broken rings or gasket leaks, thats why this is so frustraiting. I only payed $70 bucks for the saw and but $150 in parts into it. I thought this would be a easy rebuild, because the saw was in such good shape to start with. But, I was wrong. If I could fined a NEW old stock 350 I would buy it in a minute, as I don't care for the new 450, with all the EPA stuff on it and plastic front handle. I just don't want to take a chance on another used 350. Any other info would be great.

 

[TraditionalTool]

Redid a compression test with a high end Snap-on tester, that I know works. Its the gauge I use when I work on my race snowmobile and quads. Only got 130lb max. Did three test back to back with the same result. Let the saw sit over night and still won't start and when I pull the plug out the plug is wet . I have the carb set at 1.25 turns out from setted. I did a visual check of the crank seals ( without removing them ) and they look finr. I know they can look good and still leak, but I would think with the good spark, fuel and compression, it should at least pop and few times. I know the engine was put together right, no broken rings or gasket leaks, thats why this is so frustraiting. I only payed $70 bucks for the saw and but $150 in parts into it. I thought this would be a easy rebuild, because the saw was in such good shape to start with. But, I was wrong. If I could fined a NEW old stock 350 I would buy it in a minute, as I don't care for the new 450, with all the EPA stuff on it and plastic front handle. I just don't want to take a chance on another used 350. Any other info would be great.

FWIW, 130 is not bad on compression, although it should be higher with a new jug/piston/ring, that's besides the point.

One thing you can do is pull the spark plug and put the end near the threads, do you see a spark when you pull the starter rope?

Sounds like your not getting spark, IMO. I would start trying to figure out if it is or not getting spark. This is the easiest thing to check without tearing everything apart and/or replacing parts.