Rebuilt Husky 350 Running Goofy

[Wood Doctor]

I'm ready to give up on this Husky 350 that I rebuilt. I installed a new 44 mm P/C, but it would not start. Compression measures at 140 psi cold. So, I bought a new carb and replaced the old one. Now it starts, idles OK, and runs, but it has no top end at all. It sounds as if it's locked in a permanent 4-stroke mode. The RPM range is 2000 at idle to about 3200 at WOT and that's it. So, it's completely unusable.

The new carb has plastic limiters, but I doubt any adjustment to the Hi setscrew will mean anything. Frankly. I have never run into this before with any 2-cycle engine that I have ever rebuilt. Does anybody have any suggestions or an explanation for what its going on here? I'm stumped. TIA.

 

[pioneerguy600]

Is the throttle butterfly opening completely?

 

[Wood Doctor]

Is the throttle butterfly opening completely?

Yes, the throttle butterfly is completely open at WOT. I took the shroud off for a visual inspection while running. It's also blowing out too much blue smoke through the exhaust. So, it's as if it's running way too rich as well. I've never seen anything like this, except maybe a 1948 McCulloch. But even it had some power while you watched the chain spin around and you could almost count the teeth as they moved along.

 

[rupedoggy]

Bad gas, wrong coil, bad carb, timing issue, clogged muffler screen, oil tank leaking into crankcase, wrong piston, kinked fuel hose, split or partial block in the impulse, fuel filter too small or clogged, Not enough mix in the tank and the filter sucking air, high speed passage restricted, Bad spark plug.

 

[Wood Doctor]

Bad gas, wrong coil, bad carb, timing issue, clogged muffler screen, oil tank leaking into crankcase, wrong piston, kinked fuel hose, split or partial block in the impulse, fuel filter too small or clogged, Not enough mix in the tank and the filter sucking air, high speed passage restricted, Bad spark plug.

(1) Same fuel I use on all other saws. They run fine.
(2) Coil was never changed. Gap is OK. I measured it.
(3) Timing not changed but could be a possibility.
(4) Muffler screen is free of grime. Cleaned.
(5) No bar oil found anywhere near the crank case.
(6) Piston and ring came with P/C kit. Compression is good.
(7) Fuel hose is not kinked or blocked.
(8) Impulse could be a problem, but engine idles fine and starts OK.
(9) New fuel filter. No blockage.
(10) New carb, so I'm not sure how high speed passage could be blocked.
(11) New spark plug. Tried it in another 350, and it works fine.

So, what's left? I hate to install this carb into a running 350 or 353, but I suppose that may be required to be sure it's OK.

 

[BuckthornBonnie]

Oem p/c and carb?

 

[pioneerguy600]

AM carbs are hit and miss these days, was my next question for the OP. I had good results years back with the AM carbs but after seeing and getting several bad ones I am rethinking getting any more. Have 6 AM carbs here now that won`t pump fuel or can`t tune them.

 

[jltrent]

AM carbs are hit and miss these days, was my next question for the OP. I had good results years back with the AM carbs but after seeing and getting several bad ones I am rethinking getting any more. Have 6 AM carbs here now that won`t pump fuel or can`t tune them.

Same here as I use to get mostly good ones. Now maybe 50% are good.

 

[hotshot]

Frustrating...3200 max rpm.

My vote is that the ignition coil is on its way out, swap it with a known good one. Timing & spark kV is not right at high speed.

I’ve seen this twice in 200 plus sick saws, but it can happen. One was a Poulan 3400 & the other a low end Husky. Both made great blue spark on a pull test. Both would keep that blue spark visibly hopping on an in-line tester, up to a point, then scatter out or completely quit.

You should be able to lean most carbs out to send the RPMs to the moon!, but I’ve never used a clone carb.

 

[Wood Doctor]

Frustrating...3200 max rpm. My vote is that the ignition coil is on its way out, swap it with a known good one. Timing & spark kV is not right at high speed.

I’ve seen this twice in 200 plus sick saws, but it can happen. One was a Poulan 3400 & the other a low end Husky. Both made great blue spark on a pull test. Both would keep that blue spark visibly hopping on an in-line tester, up to a point, then scatter out or completely quit. You should be able to lean most carbs out to send the RPMs to the moon!, but I’ve never used a clone carb.

It's much easier for me on a Husky 350 to swap out an ignition coil than it is to swap out a carb. I have a backup Husky 350 that runs flawlessly and a Husky 353 that I ran today that also runs flawlessly. I'll remove the coil from the non-running 350 and install the coil from the running 350 and see what happens.

Once again, however, I have to wonder how a piston, a carb, and a coil could all give up together on the same saw. Maybe the original owner used this saw as a dump site for parts before he sold it to me as "project" saw. Anything is possible these days.

I will keep my fingers crossed that this coil change works. If it fails, I will give my running 350 back its coil and then hope that it works once again. But, I could go a step further. I could first check to see if the suspect coil from the non-running 350 works OK with the running 350. That means both coils are OK. Right?

 

[hotshot]

Correct. Hope it’s the coil too, as you’ve about given up on it.
Have you got an in-line spark checker?
Sometimes it’s hard to differentiate a rich carb issue from ignition. The smoking blue exhaust & dripping oil off the muffler keeps pointing you back to the carb.

 

[Wood Doctor]

Correct. Hope it’s the coil too, as you’ve about given up on it.

Sometimes it’s hard to differentiate a rich carb issue from ignition. The smoking exhaust & dripping oil off the muffler keeps pointing you back to the carb.

No oil is dripping off the muffler. Lots of smoke pours out at WOT while running 3200 RPM. But, I've not seen oil dripping out anywhere. I suppose it would if I let it smoke for 10 minutes or so. Hotshot, I will report back after I check out the coil. I might just go ahead and order a new coil, but nowadays, there is no guarantee that new parts work.

 

[a. palmer jr.]

Even we that have rebuilt several sometimes get in a hurry and make mistakes. Is it possible you might have put the piston in backwards? Don't know if that would cause what you are experiencing but it was just a thought..

 

[motor head]

Bad crank case.Some where on utube there is a video about this very thing.Bar oil could leak into the crank case causing the blue. Smoke and low RPMs

 

[a. palmer jr.]

You can rig up a timing light and turn the engine over with a half inch drill if you still suspect timing is an issue.

 

[svk]

I would say swap to a known good coil next.

Have you done pressure/vacuum test?

 

[a. palmer jr.]

Yes, I would do the easier things first. No need to take the whole saw apart only to find out you had a bad coil or a sheared flywheel key. It is likely that if the saw has a pressure/vacuum leak it would run faster than it should, not slower, unless it was a huge leak then it might not run at all..

 

[Wood Doctor]

Yes, I would do the easier things first. No need to take the whole saw apart only to find out you had a bad coil or a sheared flywheel key. It is likely that if the saw has a pressure/vacuum leak it would run faster than it should, not slower, unless it was a huge leak then it might not run at all.

My sentiments exactly. If it runs perfectly on idle and then cannot crank anymore than another 1000 RPM, then it's likely an electrical issue. The only thing left is the impulse hose, but I doubt seriously that is the problem.

Today I checked the compression timing against my Husky 353 by simply looking at the flywheel at top end. Both were identical. Sure it's a rough test, but it seldom fails for me. I am leaning toward an electrical malfunction for this 350.

I may have $150 worth of parts here for a top-notch Husky mechanic who loves a challenge, but I hate giving up.

 

[svk]

My sentiments exactly. If it runs perfectly on idle and then cannot crank anymore than another 1000 RPM, then it's likely an electrical issue. The only thing left is the impulse hose, but I doubt seriously that is the problem.

Today I checked the compression timing against my Husky 353 by simply looking at the flywheel at top end. Both were identical. Sure it's a rough test, but it seldom fails for me. I am leaning toward an electrical malfunction for this 350.

I may have $150 worth of parts here for a top-notch Husky mechanic who loves a challenge, but I hate giving up.

Don't give up, you have already eliminated almost all of the possible issues

 

[Wood Doctor]

Don't give up, you have already eliminated almost all of the possible issues.

Thanks for the encouragement. I almost yanked out the coil from my running 353 today and installed it, but decided against that. New coil is on order. Patience is next to Godliness.

BTW, this non-running 350 is cosmetically a jewel and my 353 ran flawlessly today as I used it to bring in another truckload of locust for firewood. I guess I'm a sucker for nice-looking merchandise. Tearing apart this saw to fix a non-runner seems a bit obtuse: