Walbro HD199 Fix

[modder]

please don't send me any zama carbs, thay are the worst carb ever made

I have a zama on one of my 357xp and it didn't respond nearly as well after porting. I thought I had an air leak because it wouldn't run rich enough no matter how much adjustment. I took the saw apart about 5 times, looking for an air leak but couldn't find one. I then swapped it out for the walbro from my other 357 and it adjusted the way it should. It is not even an aggressive port job, but the walbro works much better.

 

[jerrycmorrow]

thanks for the tip scott. subscribing for future reference

have a question though. what is it about the factory built carbs that made the ones fail that failed? they used wrong diaphragm?

 

[wisecobandit]

please don't send me any zama carbs, thay are the worst carb ever made

Big up to you Scott for divulging this sort of info. Being in the u.k it never made sense to send mine across the water to you, but replaced my earlier walbro 174 carb with a zama.
Having seen your vid I had to take a look inside the 174 and yup exactly the same issue as what you quoted about the gasket hole so clearly it will prob have been its issue to... :msp_rolleyes:

 

[Cantdog]

Well Scott....you and I have never conversed........been following your threads over time concerning this Walbro carb issue...in my opinion $25 to have someone rebuild/fix any carb with a new kit is cheep...let alone a very problematic one such as the 199...I have replaced the 199s with three or four Zamas for clients.....they were very happy to get the saw straightened out and running good. Good on you for sharing your remedy ....not sure I would have...if I were making my living working on saws.......to some this is a hobby...to others it is a living..either fixing or using.....big difference there....and the line should be clear between the two.....thanks for the info....now I have 3-4 screwed up 199s here...will probably ship them to you for repair as needed...could well do it myself, now.....but......I don't think so......you

 

[tree monkey]

thanks for the tip scott. subscribing for future reference

have a question though. what is it about the factory built carbs that made the ones fail that failed? they used wrong diaphragm?

ithink it was a epa thing that thay used the blue diaphragm.
all of the new kits come with the tan

 

[tree monkey]

Well Scott....you and I have never conversed........been following your threads over time concerning this Walbro carb issue...in my opinion $25 to have someone rebuild/fix any carb with a new kit is cheep...let alone a very problematic one such as the 199...I have replaced the 199s with three or four Zamas for clients.....they were very happy to get the saw straightened out and running good. Good on you for sharing your remedy ....not sure I would have...if I were making my living working on saws.......to some this is a hobby...to others it is a living..either fixing or using.....big difference there....and the line should be clear between the two.....thanks for the info....now I have 3-4 screwed up 199s here...will probably ship them to you for repair as needed...could well do it myself, now.....but......I don't think so......you

i changed my price sometime ago, $30.00 includes return shipping

 

[Cantdog]

i changed my price sometime ago, $30.00 includes return shipping

Still it kills the best of a five spot to return ship... remains a deal IMHO....

 

[jerrycmorrow]

ithink it was a epa thing that thay used the blue diaphragm.
all of the new kits come with the tan

good ole epa. what else they gonna muck up? so i'm guessing its never good to use the blue diaphragm in any carb rebuild?

 

[jammin_with_j]

Scott, you have given up something you have put great time in to. You have paid close attention to detail in differences to the replacement parts that many would have missed. I am sure there are many here that appreciate you sharing something you did not have to. Don't let one overly proud Canadian ruin the view of the rest of us. I'm sure you've worked hard to get to where you are and your clear thought out approach to the carb rebuild displays that. From my proud Canadian heart THANK YOU for being a stand up guy, and making us all sweat it out

I've got a question for ya, looking at pictures of K12-HDA kits they appear to have the missing set of holes that are required on the metering side. Would that be a closer match to the original kit used in the saw from manufacture?

 

[modder]

Scott, you have given up something you have put great time in to. You have paid close attention to detail in differences to the replacement parts that many would have missed. I am sure there are many here that appreciate you sharing something you did not have to. Don't let one overly proud Canadian ruin the view of the rest of us. I'm sure you've worked hard to get to where you are and your clear thought out approach to the carb rebuild displays that. From my proud Canadian heart THANK YOU for being a stand up guy, and making us all sweat it out

I've got a question for ya, looking at pictures of K12-HDA kits they appear to have the missing set of holes that are required on the metering side. Would that be a closer match to the original kit used in the saw from manufacture?

There is that funny again. Funny peculiar that is.
Jammin, Im glad you are here to show such a proper representation of a proud Canadian. You are just the right amount of proud.

In all seriousness, I make no apologies for being any amount of proud. In fact, I am known to encourage people to take pride in what they do and I also think people shouldn't try to discourage others from being proud. OK guys, that's your psychology lesson for today, tune in tomorrow and we can learn how to, not take yourself so damn serious.:msp_tongue:

Oh yah, us Canadians are extremely sarcastic, and proud of it.:msp_tongue::msp_tongue: Take a look back in some posts and see if you can find some.

 

[Mastermind]

There is that funny again. Funny peculiar that is.
Jammin, Im glad you are here to show such a proper representation of a proud Canadian. You are just the right amount of proud.

In all seriousness, I make no apologies for being any amount of proud. In fact, I am known to encourage people to take pride in what they do and I also think people shouldn't try to discourage others from being proud. OK guys, that's your psychology lesson for today, tune in tomorrow and we can learn how to, not take yourself so damn serious.:msp_tongue:

Oh yah, us Canadians are extremely sarcastic, and proud of it.:msp_tongue::msp_tongue: Take a look back in some posts and see if you can find some.

You know why I named myself "Mastermind"........it's because I'm lacking in self confidence and stuff.

Carry on.

 

[barneyrb]

You know why I named myself "Mastermind"........it's because I'm lacking in self confidence and stuff.

Carry on.

And to think all this time I thought you were a legend in your own mind was the reason...........Man, what a dumdazz I am...

 

[modder]

So its not just Canadians that are sarcastic....and I thought that boarder made us so different. I learn so much on this thread.

 

[Mastermind]

And to think all this time I thought you were a legend in your own mind was the reason...........Man, what a dumdazz I am...

Yeah Randy, I've been trying to figure out a way to talk to you about that. :hmm3grin2orange:

 

[jammin_with_j]

There is that funny again. Funny peculiar that is.
Jammin, Im glad you are here to show such a proper representation of a proud Canadian. You are just the right amount of proud.

In all seriousness, I make no apologies for being any amount of proud. In fact, I am known to encourage people to take pride in what they do and I also think people shouldn't try to discourage others from being proud. OK guys, that's your psychology lesson for today, tune in tomorrow and we can learn how to, not take yourself so damn serious.:msp_tongue:

Oh yah, us Canadians are extremely sarcastic, and proud of it.:msp_tongue::msp_tongue: Take a look back in some posts and see if you can find some.

When you are the one asking for help to things you don't know sometimes you gotta kill people with kindness. I see many folks here go out of their way to help when they get treated with decency.

 

[Mastermind]

When you are the one asking for help to things you don't know sometimes you gotta kill people with kindness. I see many folks here go out of their way to help when they get treated with decency.

I only remember one guy getting his panties twisted over this.........

 

[Hedgerow]

You know why I named myself "Mastermind"........it's because I'm lacking in self confidence and stuff.

Carry on.

Psshhh... And here I thought it was because you had those little yellow minions running around the shop...


Guess I learn something new every day...

 

[wcorey]

Finally got a chance to get back on those rotten carbs again.

First off...

Thanks Scott, not sure I would’ve figured that one out even with a few more hints.
To you it may have seemed obvious but for me not so much. I was getting pretty fed up
with putting so much time into two carbs and it was past time to move on anyway…


The ‘vent hole in the metering cover fix’ didn’t seem to change anything on either carb but the new style impulse diaphragm did.
Bought a couple of the cheap ebay carbs (want ‘em for 350/346’s anyway) and they have the newer type diaphragm.
Swapped the diaphragm in from one of those and got one of the bad carbs straitened right out.

The other one still has issues running very rich at wot with no response from the adj needle.
Will have to dig into that further but assume at this point it has something to do with taking it
apart about 50 times including pushing out the jets and welch plugs on more than a few occasions.
Has to be a leak where fuel is getting by somewhere.

What still baffles me is why the original good running carb was fine with the blue diaphragm
(even using the ones from the bad carbs) but the bad carbs wouldn’t run right even with the one out of the good carb.
That’s one reason I never would have figured out the problem because I assumed I had
eliminated those factors with the unsuccessful parts swapping from the good unit.

I’m guessing that whatever is the subtle difference between them is why some 'blue' carbs get flaky and others stay ok.

 

[moody]

I'm wondering if casting in the impulse area is preventing a clean impulse. On your bad carbs take a mig welder tip cleaner that's a little smaller than the hole and try feeling for any snags.

 

[modder]

I'm wondering if casting in the impulse area is preventing a clean impulse. On your bad carbs take a mig welder tip cleaner that's a little smaller than the hole and try feeling for any snags.

I'm not sure a bad impulse would make it always run rich though. I thought a poor impulse would cause it to run lean. I've seen carbs run rich when people had seated the jet screws too tight, then opened them up to get the proper setting. That can cause it to be flared and look like a funnel. I've also seen jets that have been deformed or reamed out unintentionally when people use a torch tip cleaner to remove junk from the jets. That can also cause it to surge and idle poorly. The jets should look uniform, with crisp edges, otherwise it will be hard to make that carb work properly. Not that I know everything about this specific carb, but that has been what I've experienced. The metal is fairly soft so its not that forgiving. Im sure some of the full time builders can offer some advice.