Walbro HD199 Fix
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nmurph
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Speaking of space; are you coming to the MY GTG?
SawTroll
Information Collector
Sorry, that is not possible! :msp_sad:
Mastermind
Work Saw Specialist
We been seeing if we could round up enough to get a plane ticket..........
I'll chip in !
SawTroll
Information Collector
That is not the problem, but thanks for the thought!
Trx250r180
Saw polisher
Yeah ,but how will he get home ?
sachsmo
Addicted to ArboristSite
Y'ever see "Frosty the Snowman"?
Troll can't come because if he leaves the arctic circle he will melt:msp_sad::msp_sad:
modder
ArboristSite Operative
In the boxes of parts I bought from a bankruptcy sale was lots of parts for 357 and 359. There is about 30 plastic carb plates for the 199 with a brass tube instead of the white plastic tube. It would make sense if that was the fix as the guy that owned the shop was known for being one of very few people that could repair the faulty walbros. There was also lots of diaphragms for them. Then again, there is a lot of jet screws, throttle plates and shafts. I have a couple broken 199 walbros so time to play i guess......unless anyone would like to save me lots of time and tell me what the fix is.
Anyone that had their 199 fixed by monkey should be able to tell us if they came back with a brass tube instead of the white plastic one.
Anyone that had their 199 fixed by monkey should be able to tell us if they came back with a brass tube instead of the white plastic one.
Just recently there was a thread about that tube possibly causing air leaks
and I'm guessing the brass tube is likely a fix but for a different issue than the 199 'thing'.
I've been beating my head against the 199 wall a lot lately, with little success.
I have two 359's with 'the issues' and a perfect running 357
so I can swap out the misbehaving carbs for the good one to eliminate variables.
So far all three run fine with the one good carb and all run bad with the bad ones,
so that would seem to rule out the tube you speak of as that doesn't get swapped.
Had the 199's apart dozens of times by now.
I've gone so far as to completely disassemble the good one and swap everything swappable over with a bad one.
Bad one stays bad, good one stays good.
The specific issues that come up often change by simply taking apart and reassembling,
occasionally I think I got it but then the problems come back over a short time.
Pretty frustrating, I hate it when something that seems so basic defeats me...
modder
ArboristSite Operative
So you are pulling the plastic fuel intake tube on each swap, instead of pulling the fuel line off? That sounds like it would cause an air leak. Maybe I'm not understanding. I vacume tested my bad one today and the plastic tube was sucking air so I swapped it out for a brass one. No more leaks now. I didn't get a chance to try it out on the saw to see if it works properly now but will post the results when I do. That would certinly be causing problems but we will see if it works as it should.
Eccentric
Mister Wizard
I just read 17 pages. I was hoping to learn something I might be able to use to maintain my small collection of saws. Didn't happen.
O.K. I will tell you how to calculate the ultimate heat sink capacity of a 1200 MW nuclear power plant reactor containment building in exchange for the info needed to make my Poulan 330 idle nice.opcorn: Then you can calculate the needed capacity of the open area cooling units and related ductwork. Sounds like a fair trade. Any takers?
My PP330 had an HDA164 that was acting goofy. Replaced it with an NOS HDA137 (made in Mexico). Problems went away. OEM HDA164 had a brass fuel tube. The replacement HDA137 has a plastic elbow....
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Mastermind
Work Saw Specialist
Same here. :msp_mellow:
Eccentric
Mister Wizard
Same scenario for a few folks here. I changed my carb because Mark M had solved the same problems with his PP330 by replacing the HDA164 with an HDA137 a few years earlier.
Ok, now I get what you’re referring to, the fuel line fitting/barb. I frequently have problems confusing terminology on these things.
When you wrote “plastic carb plates for the 199 with a brass tube instead of the white plastic tube”,
I wasn’t quite sure what you meant (what’s the ‘carb plate’?) and somehow jumped to the conclusion
it must be the nipple in the manifold for the impulse.
Which isn’t white and wouldn’t be on the treemonkey fixed carbs anyway.
That’s also why I said they didn’t get swapped out, because they’re not even on the carb.
My bad…
I did check the fuel barbs on all mine and none of them leaked so saw no reason to swap them out,
maybe I should investigate that angle further. I can’t see how it would affect anything if it’s not clogged
and passes pressure/vac but at this point I’ll try anything.
The bad carbs were always full of fuel when I disassembled them and the saws would typically run/four-stroke
at full throttle so it didn’t appear to be fuel starvation as would be the likely result of a leak there.
Aside from changing out most of the removable parts, I tried lots of other things including alterations
to the main fuel nozzle and it’s supply jet, the accel pump and passages, the metering lever and spring.
Compared parts under a binocular microscope. Numerous ultrasonic cleanings.
At this point I suspect it’s something with the main body of the carb, only because that has been the one common denominator so far.
Feels like I can’t see the forest for the trees, that I’m missing something painfully obvious.
modder
ArboristSite Operative
Sorry, the clarity got lost somewhere between my head and my fingers. After reading my own post again, I see how it didn't make sense and is confusing. I certainly don't know all of the proper terminology. Maybe I have been getting different symptoms from by bad walbro. It was difficult to accelerate without feathering the throttle but once you got past that dead spot, it would rev up but only 4 stroke very slightly. The idle was also all over the place, then stall. It seamed like the slightest adjustment of the jets would sometimes have very odd outcomes, and sometimes, seamed to do nothing at all. When I swapped back to the zama, all symptoms went away. My playtime will be very limited for the next few days so I probably will not get to see if the repair fixed the problem until the weekend.
Hey Monkey, can you give me a tip....tell me if i am hot or cold, freezing to death or standing on the fire....I completely understand why you are not just passing out the fix, but can we have a crumb....or if you cant, can anyone tell me where I can send mine to in Canada if I cant figure it out myself. I don't like the idea of shipping a carb to another country for repair. Just sending a carb to someone else for repair kills me. Its not the money, its just the thought of me not doing the repair myself. I'm sure there is others on the site that can understand that one.
Hey Monkey, can you give me a tip....tell me if i am hot or cold, freezing to death or standing on the fire....I completely understand why you are not just passing out the fix, but can we have a crumb....or if you cant, can anyone tell me where I can send mine to in Canada if I cant figure it out myself. I don't like the idea of shipping a carb to another country for repair. Just sending a carb to someone else for repair kills me. Its not the money, its just the thought of me not doing the repair myself. I'm sure there is others on the site that can understand that one.
M
moody
Guest
Scott's been busy so I wouldn't expect a reply. People have tried to get him to post his fix publicly or give tips. He won't do that nor should he be expected to. He's one of the best saw builders I know of and knows a few tricks that put him on a different level than most. He worked hard to learn those tricks and technique's and I don't blame him for not sharing publicly. Don't take that as he's a jerk or greedy because he's far from it. He's a great builder and a good friend and has answered anything I've asked him. But I consider those tricks he knows as something I'll figure out when I'm ready. Until then I keep trying to learn on my own. When I run into a 199 that needs help I'm not ashamed at all to send it to him. I haven't had to do that yet. I've been fortunate to get by so far with zero issues from this carb. I'm sorry that people who are needing help I'm unable to provide it. To be honest if I figure it out I'll probably won't announce it.
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modder
ArboristSite Operative
I dont blame Scott, nor do I think he is a greedy jerk. He does saw work for a living and I no longer even use saws to make my own living. The repairs and mods are just enjoyment and I like knowing that whatever goes wrong, I can fix it, but in this case, its probably going to take a while to figure this one out. I know I have the option of picking up another carb but its just a pride thing.
Justsaws
Addicted to ArboristSite
Remove the metering diaphragm cover.
Remove diaphragm.
Hold carb level, diaphragm side up, fill cavity with mix.
Pull throttle lever back WOT.
Release throttle lever back to idle, repeat.
Should see squirt of fuel from A pump. If not A pump faulty, circuit plugged, pump plunger stuck or steel welch on face of carb(not the brass dust cover) leaks.
Mostly likely plugged circuit.
Supposedly carbs were replaced because Walbro/Husq did not offer an A pump service kit, if the brass plunger/o-ring was worn enough to need replacement the alloy carb body was probably suspect as well, with no service kit available cleaning the circuit may or may not be cost effective.
Different opinions on how to clean and or unstick the pump cylinder. Supposedly there was no steel welch available from Walbro so if you choose to remove it make sure you can fab up a replacement. Do not recommend any solvent that can degrade a rubber o-ring.
Carb must be submerged to check for leaks and throttle shaft must be moved.
The carb trouble shooting chart on the Walbro website will narrow down carb issues.
If the saw is a low hour sit on a shelf more time than not saw chances are the brass plunger is not worn out. Clean and check for leaks. O-ring may still be suspect.
If the saw sees A LOT of throttle blipping use then it is much more possible that the brass plunger has started to wear and or o-ring leaks.
Remove diaphragm.
Hold carb level, diaphragm side up, fill cavity with mix.
Pull throttle lever back WOT.
Release throttle lever back to idle, repeat.
Should see squirt of fuel from A pump. If not A pump faulty, circuit plugged, pump plunger stuck or steel welch on face of carb(not the brass dust cover) leaks.
Mostly likely plugged circuit.
Supposedly carbs were replaced because Walbro/Husq did not offer an A pump service kit, if the brass plunger/o-ring was worn enough to need replacement the alloy carb body was probably suspect as well, with no service kit available cleaning the circuit may or may not be cost effective.
Different opinions on how to clean and or unstick the pump cylinder. Supposedly there was no steel welch available from Walbro so if you choose to remove it make sure you can fab up a replacement. Do not recommend any solvent that can degrade a rubber o-ring.
Carb must be submerged to check for leaks and throttle shaft must be moved.
The carb trouble shooting chart on the Walbro website will narrow down carb issues.
If the saw is a low hour sit on a shelf more time than not saw chances are the brass plunger is not worn out. Clean and check for leaks. O-ring may still be suspect.
If the saw sees A LOT of throttle blipping use then it is much more possible that the brass plunger has started to wear and or o-ring leaks.
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