Huh, thought I had it fixed!

[Bret4207]

Worked on my kids 306A Poulan he was gifted the other day. Real hard starter unless primed, died out if given gas. Long story/short- pump side of the HS carb was put together backwards, pump was a bit stiff, needle on metering side discolored, maybe distorted a bit, replaced pump, gasket, needle, diaphragm and gasket after cleaning all passages. Checked reed valves, and cleaned carbon off them, they sit nice and flat. New carb to reed valve body gasket. Ended up replacing both fuel lines, cleaned tank out, cleaned felt filter too. Started up and ran good, messed with carb for some time and found it would load up and die at idle unless the low speed was set just right, half a hair either way and it would either load up and die at idle or not have enough fuel to accelerate. Thought I had it licked. Today it wouldn't start unless primed and I'm right back to loading up and dying or not having enough fuel to accelerate unless I pull the choke out a bit. Everything says I'm not getting enough fuel. The needle metering lever was set flush with the floor of the carb. I'm leaning towards the metering lever needing a little more height. ??? Having a brain fart with this one I guess.

Only other thing that crosses my mind is that this carb has a governor, some sort of doohicky that I read allows extra fuel to flow if the saw revs too high? I know nothing about it beyond that.

 

[HarleyT]

Sounds like an air leak somewhere in the system.

 

[pioneerguy600]

#19 on the IPL, if its defective the carb won`t tune proper, since the first link won`t work for others maybe this one will and its the main page with all carbs, click on the HS carb ,
https://tillotson.ie/kits-parts/illustrated-parts-lists/

 

[JP56]

#19 on the IPL, if its defective the carb won`t tune properly.

https://tillotson.ie/wp-content/uploads/2015/07/HSPartsList.pd

bad link, just the search page

 

[pioneerguy600]

bad link, just the search page

That sucks, just Google Tillotson HS carb.

 

[hotshot]

Regardless, the HS-59 A/B shows to not use a nozzle item 19...those must be a straight drilled type.

OP: Is yours a Tillotson HS-59A, B, or the early 198A carb?

The cork gasket 5300-19008 located under the reed plate can’t be dried up or distorted, else the impulse & also carb intake draw is too weak. Also make sure the carb to intake flange gasket -19023 has the impulse hole lined up.

Those felt sleeve type filters do tend to clog when the 2 stroke oil repeatedly dries up on them, so do a puff test with your mouth & a short piece of hose.

 

[hotshot]

Weird HS models, I just looked at both 59 & 198 spare carbs, & they have nothing but a drilled hole in the venturi...

 

[Bret4207]

Regardless, the HS-59 A/B shows to not use a nozzle item 19...those must be a straight drilled typ
OP: Is yours a Tillotson HS-59A, B, or the early 198A carb?

The cork gasket 5300-19008 located under the reed plate can’t be dried up or distorted, else the impulse & also carb intake draw is too weak. Also make sure the carb to intake flange gasket -19023 has the impulse hole lined up.

Those felt sleeve type filters do tend to clog when the 2 stroke oil repeatedly dries up on them, so do a puff test with your mouth & a short piece of hose.

Did the puff test as you call it after I cleaned it, filter was clear. The cork gasket sounds like something to look at. I think this thing sat for a long time before the boy got it. Think this is the 59a but I'll have to look to make sure. Thanks!

 

[Bret4207]

That sucks, just Google Tillotson HS carb.

Ha! Drives ya nuts sometimes, doesn't it?! I've got the files downloaded. I think I'm going to research that a bit, never been into one of those. Thanks!

 

[pioneerguy600]

I have two of them here bought around 1979 that dad and I ran in the woods for close to 5 years, they still have their original carbs that have never been touched, still run but havn`t cut wood with them for over 10 years. I couldn`t even tell you what carbs are on them, never needed anything on them except muffler replacement. Carbs can be a a pain at times, I have two Walbro HDC`s that are not 100% right now but I will win.

 

[Old2stroke]

The governor (#26) is a rattle ball device and if it sticks open can cause all kinds of too rich running above idle. When I find a saw with inconsistent running above idle, I just disable the damn thing and get it out of the equation.

 

[Bret4207]

"Rattle ball", that's the term I've heard describing it. Be inbteresting to see just what it looks like. It sure sounds like it could cause problems.

 

[Bret4207]

I have two of them here bought around 1979 that dad and I ran in the woods for close to 5 years, they still have their original carbs that have never been touched, still run but havn`t cut wood with them for over 10 years. I couldn`t even tell you what carbs are on them, never needed anything on them except muffler replacement. Carbs can be a a pain at times, I have two Walbro HDC`s that are not 100% right now but I will win.

I've got a 4200 that about as rock solid a saw as you could ask for, considering it's been beat to death. Poulan didn't always make plastic Walmart saws! But yeah, carbs can be tricky little devils. The HS is about as simple a carb as you can get and I've done a lot of them successfully. Reed valves saws...those I haven't played with much but I don't think the intake system itself is the problem. Thanks for the help.

 

[pioneerguy600]

"Rattle ball", that's the term I've heard describing it. Be inbteresting to see just what it looks like. It sure sounds like it could cause problems.

Just plug it with a disc punched from an aluminum can, I do that as it can be removed if wanted after all other things are ruled out. The engine will run fine with it plugged off and just tune the carb proper.

 

[Old2stroke]

"Rattle ball", that's the term I've heard describing it. Be inbteresting to see just what it looks like. It sure sounds like it could cause problems.

It's called a "rattle ball" because all it is, is a ball bearing held against an orifice by a spring and at a high enough frequency the spring can't hold it closed and it rattles loose from the orifice letting fuel flow through. Poor excuse for a governor.

 

[pioneerguy600]

I've got a 4200 that about as rock solid a saw as you could ask for, considering it's been beat to death. Poulan didn't always make plastic Walmart saws! But yeah, carbs can be tricky little devils. The HS is about as simple a carb as you can get and I've done a lot of them successfully. Reed valves saws...those I haven't played with much but I don't think the intake system itself is the problem. Thanks for the help.

You are very correct in that Poulan did make fine chainsaws years back before being bought out to cut down on competition. Up here in Canada we could not get US made Poulan saws for many years during the 80`s, couldn`t even get replacement parts so we had to change over to other makers saws and move on from there. I an sure we would have owned and ran the 4000 and 5000 series Poulans if we could have acquired them here during those years. Some how Sachs Dolmar found their way here and we picked them up.

 

[SteveSr]

"Rattle ball", that's the term I've heard describing it. Be inbteresting to see just what it looks like. It sure sounds like it could cause problems.

If the ball gets crudded up and doesn't seal the passage correctly you now have an air leak in the carb. Had an ancient Stihl trimmer with one of these. Drove me nuts till I figured it out. These are a pain to clean out. Best bet is to fill the spring cavity with carb cleaner and then throw the whole thing into the ultrasonic for a few cycles and then rinse the spring cavity... or maybe jam a wood toothpick in there to hold the spring cavity open.

 

[Bret4207]

You are very correct in that Poulan did make fine chainsaws years back before being bought out to cut down on competition. Up here in Canada we could not get US made Poulan saws for many years during the 80`s, couldn`t even get replacement parts so we had to change over to other makers saws and move on from there. I an sure we would have owned and ran the 4000 and 5000 series Poulans if we could have acquired them here during those years. Some how Sachs Dolmar found their way here and we picked them up.

LOVE my Sachs Dolmars! Really nice saws!

 

[pioneerguy600]

LOVE my Sachs Dolmars! Really nice saws!

They were a big step up for us, the AV, power and durability were great. Production increased close to two fold once we got used to running them. Still have them all and they are ready to go out cutting any time. Drained the fuel and oil out of them over 10 years ago, they only get fueled now for ceremonial cuts.

 

[Old2stroke]

If the ball gets crudded up and doesn't seal the passage correctly you now have an air leak in the carb. Had an ancient Stihl trimmer with one of these. Drove me nuts till I figured it out. These are a pain to clean out. Best bet is to fill the spring cavity with carb cleaner and then throw the whole thing into the ultrasonic for a few cycles and then rinse the spring cavity... or maybe jam a wood toothpick in there to hold the spring cavity open.

The governor is actually in a passage that will bypass extra fuel to the main jet when it opens, making the mixture so rich the saw won't rev up. They are often very hard to remove as they are installed with a good thread sealer, I just leave them alone and plug the hole in the diaphragm chamber where it gets its fuel from.