Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

McCulloch saw will not prime carb


rebel63's Avatar
Member

Join Date: Apr 2010
Posts: 69
MA

04-22-10, 11:46 AM   #1  
McCulloch saw will not prime carb

hey... I used my rarely used chainsaw yesterday and it worked fine. Today I attempted to use it and the usual six pumps on the primer bulb didn't go as usual and the saw will not run.
All the lines have been replaced recently and are intact and flowing freely, so it isn't that. It seems that fuel will not flow thru the carb itself.
This unit doesn't see much action and still has the original chain even though it is about 10-12 years old. It is a McCulloch MAC 3216.
Can anyone tell me what might be going on? Should I remove the carb and clean something? Rebuild it? Any idea on where to get carb parts? Thanks!

 
Sponsored Links
jnt412's Avatar
Member

Join Date: Dec 2007
Posts: 84
MD

04-22-10, 12:27 PM   #2  
Is fuel entering the primer bulb?.. Remove the carb. and give it a good cleaning.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

04-23-10, 01:10 AM   #3  
Check for spark, and while the plug is out, is it wet?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
rebel63's Avatar
Member

Join Date: Apr 2010
Posts: 69
MA

04-23-10, 09:09 AM   #4  
bulb did not fill with fuel like it usually would. I took the carb off and took one side off, it had one screw in the middle, it was clean... spotless. I took off the other side, two screws, and found a diaphram type of gasket, again it was all perfectly clean. I put it all back together and tried to "prime" it and the fuel still didn't come into the bulb and it wouldn't start.

 
rebel63's Avatar
Member

Join Date: Apr 2010
Posts: 69
MA

04-23-10, 09:14 AM   #5  
the spark is there and the existing plug was slightly wet when I took it out. I put in a new plug and got good spark and it still wouldn't start. Gotta be the carb, huh?

 
rebel63's Avatar
Member

Join Date: Apr 2010
Posts: 69
MA

04-23-10, 09:33 AM   #6  
OK.... pulled the carb again and disassembled it. Geez... there is a little needle and seat in there! Didn't find anything of interest... Can I put this back together or do I need to replace the gaskets/diaphram things? I bet there ain't no reusing these things, huh? That is why I didn't want to take it apart... now where do I get the new parts?

 
rebel63's Avatar
Member

Join Date: Apr 2010
Posts: 69
MA

04-23-10, 12:59 PM   #7  
After reading other postings on another thread, I have a clear picture of how this system works. I have read other stuff about the fuel system posted by "cheese" and after playing with my carb and purge system, I'm finding that there is something blocking fuel flow in the carb. I'm going to disassemble it again and see if I can find what it is. I will pay particularly close attention to the needle and seat area. Is the screen just before the seat removable? And, is it OK to reuse the gasket components?

 
hopkinsr2's Avatar
Member

Join Date: Feb 2005
Posts: 1,561
Non-US

04-23-10, 07:05 PM   #8  
Put a rebuild kit in it,, It'll save you a lot of headaches...The diaghraghms get stiff over time & they wont work well,,, Roger

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

04-24-10, 01:40 AM   #9  
I agree. Sometimes they can be re-used, but yours is old and probably stiff and ready to be replaced. A kit shouldn't set you back much $.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
rebel63's Avatar
Member

Join Date: Apr 2010
Posts: 69
MA

04-24-10, 08:40 AM   #10  
OK.... thanks for the input. Can someone tell me if the little "cup shaped" screen just before the needle and seat is removable. I don't want to mess with it and then find out I wasn't supposed to and now it's junk. Maybe a kit to rebuild it would answer that question, but I think my issues might lie in that area and I'd like to get a look before chasing down parts.

 
rebel63's Avatar
Member

Join Date: Apr 2010
Posts: 69
MA

04-24-10, 08:49 AM   #11  
OK... I'll admit it, I'm "internet search challenged"... Can anyone direct me to a site that has parts for the carb on my McCulloch MAC 3216. I swear this "information superhighway" is full of potholes....

 
bob22's Avatar
Member

Join Date: Jul 2006
Posts: 553
PA

04-24-10, 11:40 AM   #12  
See this link for parts manual:
http://manuals.aonly.com/index.php?d..._32cc-35cc.pdf

Evidently there are two different carbs on these I think:
A Zama and a Walbro.
THere is a part number for each to use in rebuilding the carb but you need to know which carb you have to order the right kit.
Come back with that info and should be able to direct you to a site.
Some parts sites:
Partstree.com - Genuine replacement parts for Toro, Echo, Husqvarna, Cub Cadet, Troy Bilt, Lawn Boy (Lawnboy), lawn equipment (lawn mowers, saws, blowers, trimmers, snow blowers) and Tecumseh, Kohler and Briggs and Stratton Engines.

KIT CARBURETOR ZAMA | Cheap Online Parts

Chainsaw Parts - Bars, Chains & Sprockets For All Models

 
rebel63's Avatar
Member

Join Date: Apr 2010
Posts: 69
MA

04-26-10, 02:38 PM   #13  
OK... Thanks to all. After reading other similar threads, I got a complete understanding of the carb system and was able to diagnose the issue and finally tracked down the problem. I pulled the screen and found the needle and seat was barely passing fuel. When I pulled just the needle and sprayed carb cleaner through the seat, I thought all was well when it sprayed thru the screen below the seat. NOT SO... when I finally pulled the screen I couldn't even see thru the seat passage below the needle. I chased the opening with a small drill bit from my oxy/acetylene torch cleaning kit and reassembled everything. A half dozen pumps on the primer and fuel was flowing normally again. Pumped it until the air bubbles were gone and fired that mother up!!! All is well and thank you for the info and the parts sites. Take care...

 
Search this Thread