Rebuilt 357XP problems

[Brian_42]

I just rebuilt a Husky 357XP with a Walbro carb today (ebay purchase), I installed a used cylinder, new OE Husqvarna piston/ring, and bearings. I just got everthing together, I replaced the plastic manifold clamp with a metal one, plastic one was broken, most likely the source of the scorred piston/cylinder. The saw will start great, and runs fastastic for about 3-5 seconds, then die like the someone hit the kill switch.

Any input or advice from you pros out there is greatly appreciated.

 

[394xp]

whats your carb settings at it should run on 1 turn on H and 1 on the L screw then tune form there

 

[Brian_42]

whats your carb settings at it should run on 1 turn on H and 1 on the L screw then tune form there

The carb setting screws have the limit nubs on them and will only go a 3/4 turn... I contimplated taking them off, but then thought I should start here. I did 1/4 turn adjusts while trying to start and keep running, but to no avail... So, should I remove the nubs and adjust like my other saws?

 

[394xp]

The carb setting screws have the limit nubs on them and will only go a 3/4 turn... I contimplated taking them off, but then thought I should start here. I did 1/4 turn adjusts while trying to start and keep running, but to no avail... So, should I remove the nubs and adjust like my other saws?

I think I would take them off I took them off on my ms361 and it is a lot easier to tune

 

[Brian_42]

I think I would take them off I took them off on my ms361 and it is a lot easier to tune

Off to the garage with a small file, will post results shortly....
Thanks very much for the quick advice!

 

[Brian_42]

Okay, here's where we're at: nubs removed from carb set screws, adjust to initial settings, 1 turn out each. The saw still behaves the same, did a few adjusts to see if anything helped, didn't seem to. Another tid-bit I just learned: If I pull the starter with the choke out, and throttle wide open, the saw starts and I can hold moderate rpm's that increase as to where I place the choke lever, as the choke is pushed in, the saw revs higher, then shuts off when the choke is off...???

 

[00 steve]

Okay, here's where we're at: nubs removed from carb set screws, adjust to initial settings, 1 turn out each. The saw still behaves the same, did a few adjusts to see if anything helped, didn't seem to. Another tid-bit I just learned: If I pull the starter with the choke out, and throttle wide open, the saw starts and I can hold moderate rpm's that increase as to where I place the choke lever, as the choke is pushed in, the saw revs higher, then shuts off when the choke is off...???

sounds lean. low jet problem, pinched/cracked fuel line, or fuel tank vent. run with choke on , but not with the choke off is a classic lean symptom.

 

[Brian_42]

sounds lean. low jet problem, pinched/cracked fuel line, or fuel tank vent. run with choke on , but not with the choke off is a classic lean symptom.

I was thinking possibly the gas tank vent, but I'm not sure where that is... So... I guess my next move is to pull the handle/tank assy. and check the fuel line to make sure it's 100%... If everything checks out between the tank and the carb, my guess is a carb kit? I've never rebuilt a carb before, so I'm not sure what all is involved, any advice if that's what I have to do?

 

[394xp]

Okay, here's where we're at: nubs removed from carb set screws, adjust to initial settings, 1 turn out each. The saw still behaves the same, did a few adjusts to see if anything helped, didn't seem to. Another tid-bit I just learned: If I pull the starter with the choke out, and throttle wide open, the saw starts and I can hold moderate rpm's that increase as to where I place the choke lever, as the choke is pushed in, the saw revs higher, then shuts off when the choke is off...???

I had a saw that did the same choke thing, did you put a new carb kit in the carb? when mine did that I put the old needle lever back in the saw and it ran like a champ. I think the problem was that the new needle lever was bent different so it was flooding the saw, if you still have the old one I would put the needle leaver back in it and make sure that all the gaskets are in the right order. If you take the air filter off give the saw some pulls and see if there is gas in the air intake where the air filter sits on.

 

[00 steve]

You definitely are getting more air and not enough fuel. double check the intake hose and tank vent before taking the saw too far apart. if it comes to a carb rebuild the walbro is easy to rebuild. pay attention to how it comes apart and take your time.

 

[Brian_42]

I had a saw that did the same choke thing, did you put a new carb kit in the carb? when mine did that I put the old needle lever back in the saw and it ran like a champ. I think the problem was that the new needle lever was bent different so it was flooding the saw, if you still have the old one I would put the needle leaver back in it and make sure that all the gaskets are in the right order. If you take the air filter off give the saw some pulls and see if there is gas in the air intake where the air filter sits on.

I never rebuilt the carb (and, unfortunately... never have), I removed the intake/carb/air-cleaner as an assy when I pulled the cylinder from the saw, so I haven't touched that... I'm hoping for a bad fuel line or filter... Are the rebuild kits they sell on ebay easy to install? I'm comfy replacing the top end on a saw, even considering doing a muffler mod on this one if I can get it running right....

 

[Brian_42]

You definitely are getting more air and not enough fuel. double check the intake hose and tank vent before taking the saw too far apart. if it comes to a carb rebuild the walbro is easy to rebuild. pay attention to how it comes apart and take your time.

Thanks Steve,
I just noticed what looks like place for a hose on the cylinder on the compression release side... with no hose....???? The cylinder I pulled did not have that????? I think this may be my issue, advice on what to do with this, or what this is?

 

[394xp]

Thanks Steve,
I just noticed what looks like place for a hose on the cylinder on the compression release side... with no hose....???? The cylinder I pulled did not have that????? I think this may be my issue, advice on what to do with this, or what this is?

That is going to be the impulse line your saw will need that to run I think a piece of gas line will work to replace it
try this for some more help http://www.gardening-tools-direct.co.uk/content/husqwm270_hwen2000_1019117-26.pdf
it is a manual for the saw

 

[Brian_42]

That is going to be the impulse line your saw will need that to run I think a piece of gas line will work to replace it
try this for some more help http://www.gardening-tools-direct.co.uk/content/husqwm270_hwen2000_1019117-26.pdf
it is a manual for the saw

The problem I'm seing here, is I have no idea where to run a hose to from this open port... The cylinder I pulled from the saw did not have this and I can't find anyplace to run this... I'm assuming it should run to the intake?? carb?? I appreciate the shop manual, but I'm still struggling with the fact that I didn't have this to begin with... and now I do....

 

[00 steve]

Your saw has to have a way to pump the fuel. this is usually done with pressure pulses via some sort of an impulse path. the pro saws I have seen use an impulse line. it will run from the cylinder to the carb. when you try to run your saw, it is sucking air through the impulse fitting on the cylinder making the fuel charge too lean. you need a good ipc. if I can find one I will post the link.

 

[394xp]

The problem I'm seing here, is I have no idea where to run a hose to from this open port... The cylinder I pulled from the saw did not have this and I can't find anyplace to run this... I'm assuming it should run to the intake?? carb?? I appreciate the shop manual, but I'm still struggling with the fact that I didn't have this to begin with... and now I do....

yep it should run to the I can't find the words right lets say "fire wall" or on the the carb
could you post any pics of what you see

 

[00 steve]

394XP posted a good reference. look at page 33 and let us know if that helps clarify.

 

[Brian_42]

There's a hose on the bottom of the intake, but it hooks back up to the intake, looks like it makes a loop... I sure wish I would have noticed this before I got the whole thing back together, I planned on cutting tonight...

 

[394xp]

There's a hose on the bottom of the intake, but it hooks back up to the intake, looks like it makes a loop... I sure wish I would have noticed this before I got the whole thing back together, I planned on cutting tonight...

Have a look at this pic your saw should have this hole at the bottom of the intake, if it does not you might have to hook your impulse line to the hole on your cylinder http://www.arboristsite.com/chainsaw/173631.htm

 

[Brian_42]

Have a look at this pic your saw should have this hole at the bottom of the intake, if it does not you might have to hook your impulse line to the hole on your cylinder http://www.arboristsite.com/chainsaw/173631.htm

My saw had that exact arrangement, I noticed it because I used it to align when I put the intake on the cylinder... so.... What is this on the side of my cylinder?