Husqvarna 460 dies if throttle is opened

Short Game · Mar 28, 2012

Today I took some time with the 460 Rancher. I just took covers off and looked around again, blew some dirt out of places that would not likely make any difference (it was all pretty clean around the carb and throttle linkages). I ran it a bunch of times and nothing seemed changed. I took the bar and chain off and ran it. I took the air filter off and ran it. No change. It would stall when I opened up the throttle.

I noticed that the chain oiler really was moving a lot of oil. So, I decided to adjust it. I found that it got plenty of oil at the lowest setting on the adjustment screw. I was just starting it and giving it whatever amount of throttle it would take without that stalling thing to see how much chain oil was coming out. While doing this, it started running okay at full throttle again. I put the bar and chain back on and the top cover too. Still was working right. WTF? As soon as the rain stops I will be needing to get some work out of it. I took my old Stihl back-up out of the tractor scabbard and put the Husky back in. Wish me luck.

GreatWhitehunter · Mar 28, 2012

I had a similar issue with my Stihl and the fuel pickup and hose were bad. I had to take out the gas tank to pull the fuel line. Might want to check it out.

Matt

JRobyn · Mar 29, 2012

I've seen that behavior out of various 2-cycle engines due to gummed carbs. Gum/debris sems to only be in the high-speed carb passages. It is relatively cheap to dump in a bit of SeaFoam, and that stuff can do absolute miracles on gummy 2-cycle carbs, particularly when they are in the partly clogged, intermittent-running state you seem to be in.

Short Game · Mar 30, 2012

JRobyn said:
I've seen that behavior out of various 2-cycle engines due to gummed carbs. Gum/debris sems to only be in the high-speed carb passages. It is relatively cheap to dump in a bit of SeaFoam, and that stuff can do absolute miracles on gummy 2-cycle carbs, particularly when they are in the partly clogged, intermittent-running state you seem to be in.

I have never heard of that stuff, so I searched around. I watched the company videos and others. I thought, what is this stuff if it's all petroleum? So I searched some more and bumped into this interesting page: Homebrew Sea Foam (SeaFoam) Motor Treatment Recipe

namesray · Mar 30, 2012

GreatWhitehunter said:
I had a similar issue with my Stihl and the fuel pickup and hose were bad. I had to take out the gas tank to pull the fuel line. Might want to check it out.

Matt

this is what i was leaning towards too.

Chilly807 · Apr 1, 2012

Check the spark arrestor screen on the muffler, if it's clogged with carbon the engine won't be able to breathe properly. You can try removing it and run the saw to see if it helps. If not try turning the low speed screw slightly CCW to richen the mixture and help with acceleration.

Sean

Short Game · Apr 1, 2012

Chilly807 said:
Check the spark arrestor screen on the muffler, if it's clogged with carbon the engine won't be able to breathe properly. You can try removing it and run the saw to see if it helps. If not try turning the low speed screw slightly CCW to richen the mixture and help with acceleration.

Sean

You know, one of the last things I did before it started running at full throttle again was to slide the screen out. It looked clear and clean, so I slid it back in and replaced the screw. I didn't mention that because I didn't think I'd done anything. Still don't, really. But since you mentioned it... Weird, huh?

Short Game · Apr 2, 2012

The first test of the Husky.

Finally got a break in the rain today. I have been cleaning up brush from a big tree I dropped in December before it gets completely grown into the grass that's ahead of schedule this year. It worked fine except for on one of many restarts when it showed just a little hesitation to take full throttle. I just kept bringing the revs up to where it started to cough and backing off and repeating that. Within 15 seconds or so it was back running okay.

I suppose that sliding the spark screen out could have scraped off some unseen carbon buildup.

Anyway, glad to have my saw back working for now.

IndyIan · Apr 2, 2012

Short Game said:
The first test of the Husky.

Finally got a break in the rain today. I have been cleaning up brush from a big tree I dropped in December before it gets completely grown into the grass that's ahead of schedule this year. It worked fine except for on one of many restarts when it showed just a little hesitation to take full throttle. I just kept bringing the revs up to where it started to cough and backing off and repeating that. Within 15 seconds or so it was back running okay.

I suppose that sliding the spark screen out could have scraped off some unseen carbon buildup.

Anyway, glad to have my saw back working for now.

What colour is the plug? I still don't like the sound of how its running. If the plug is black you probably aren't hurting anything running it, if its white then you need to figure why its getting lean up in the revs and fix it as lean = low lubrication and maybe a stuck piston after a while...