Alaskan Stihl
ArboristSite Operative
Ok…I acquired a McCulloch Eager Beaver (boat anchor). Of course, right off then bat, it doesn’t start properly and once started…runs extremely rough.
I ordered a rebuild kit (Walbro MDC-16) and rebuilt the Carburetor. After the rebuild, I recalled that a “pressure bench test” should be conducted. Here is what I did:
#1. Threaded in both H and L screws
#2. Attached PSI Gauge to fuel outlet nozzle.
#3. Pumped up to 7PSI
I found that it bled off quite rapidly. After squirting soap around top plate; I discovered small bubbles. I then tightened up the (4) screws a little more and tested again. It bled down slower…but still bled down.
I was going to say the heck with it and try putting everything back together to see if the Piece of Crap would run…when luck would have it… I broke the plastic throttle lever while I was trying to get the metal lever snapped into place.
At that point; frustration took over and I tossed the damn thing in a plastic bin and threw it on a shelf!!!!
After calming down…
I ordered a new throttle lever (it is now on the way)…however…from what I read, those models of Carburetors are extremely temperamental and I should probably resolve any issues still in question.
Which brings us to those questions…
Number #1: I have read where these Walbro MDC Carbs are JUNK. I have a McCulloch 110 that has a ZAMA M7-2YP. Could I replace the Walbro MDC-16 and purchase & install a ZAMA M7-2YP in place?
Number #2: Did I conduct the Pressure Test correctly? Is the Walbro MDC-16 accommodating to this kind of “Pressure Bench Test” or is it designed in a way that allows it to bleed off? I watched a YouTube in which the Mechanic was having the same problem with the Carb failing the pressure test…(he cut the video off before resolving the issue).
Number #3: Finally, if everything is…as it should be….and it failed the pressure test due to fault, then what is that fault? Could it be the Check Valve (supposedly, there is a check valve behind one of the “Welch Plugs”).
Question #4: My Carb Rebuild Kit came with new Welch Plugs…however; it did not come with a check valve assembly. Where could I find a new a new Check Valve Kit for this Carburetor?
Thanks to anyone who can help!
Alaskan Stihl
I ordered a rebuild kit (Walbro MDC-16) and rebuilt the Carburetor. After the rebuild, I recalled that a “pressure bench test” should be conducted. Here is what I did:
#1. Threaded in both H and L screws
#2. Attached PSI Gauge to fuel outlet nozzle.
#3. Pumped up to 7PSI
I found that it bled off quite rapidly. After squirting soap around top plate; I discovered small bubbles. I then tightened up the (4) screws a little more and tested again. It bled down slower…but still bled down.
I was going to say the heck with it and try putting everything back together to see if the Piece of Crap would run…when luck would have it… I broke the plastic throttle lever while I was trying to get the metal lever snapped into place.
At that point; frustration took over and I tossed the damn thing in a plastic bin and threw it on a shelf!!!!
After calming down…
I ordered a new throttle lever (it is now on the way)…however…from what I read, those models of Carburetors are extremely temperamental and I should probably resolve any issues still in question.
Which brings us to those questions…
Number #1: I have read where these Walbro MDC Carbs are JUNK. I have a McCulloch 110 that has a ZAMA M7-2YP. Could I replace the Walbro MDC-16 and purchase & install a ZAMA M7-2YP in place?
Number #2: Did I conduct the Pressure Test correctly? Is the Walbro MDC-16 accommodating to this kind of “Pressure Bench Test” or is it designed in a way that allows it to bleed off? I watched a YouTube in which the Mechanic was having the same problem with the Carb failing the pressure test…(he cut the video off before resolving the issue).
Number #3: Finally, if everything is…as it should be….and it failed the pressure test due to fault, then what is that fault? Could it be the Check Valve (supposedly, there is a check valve behind one of the “Welch Plugs”).
Question #4: My Carb Rebuild Kit came with new Welch Plugs…however; it did not come with a check valve assembly. Where could I find a new a new Check Valve Kit for this Carburetor?
Thanks to anyone who can help!
Alaskan Stihl