Author Topic: Carb ?  (Read 621 times)

0 Members and 0 Guests are viewing this topic.

Offline Old Iron Logging

  • Nitro Hotsaw
  • *******
  • Posts: 1132
  • Karma: 81
Carb ?
« on: March 06, 2011, 08:34:05 pm »
Carb is a Walbro HDA 205-C. Set to factory spec the saw turns 12,700. Manual says to set saw to 13,500 post break-in. Trouble is, as you make the carb setting leaner, the saw looses rpm. With the H closed off saw holds 12,000 rpm. Acts like a fuel governed carb, but see no governor on it. Tech at ESF saws the carb is not governed. Any ideas?

Share on Facebook Share on Twitter


Offline stihlbro

  • 4 cube
  • **
  • Posts: 70
  • Karma: 9
  • Location: virginia
Re: Carb ?
« Reply #1 on: March 07, 2011, 11:57:16 am »
Do you have another carburetor to bolt on to eliminate the one on it now?  To me if you close off the hs needle it should stop fuel supply, so it shouldn't turn 12,000 rpm. Sounds like the main jet is getting fuel from somewhere else because I dont see the low speed jet suppling enough fuel to turn that rpm. The last hda i remember had a brass plug over top of the main jet, I wonder if this is leaking? Fuel is getting to the engine somehow to run wide open throttle.

Offline Old Iron Logging

  • Nitro Hotsaw
  • *******
  • Posts: 1132
  • Karma: 81
Re: Carb ?
« Reply #2 on: March 07, 2011, 12:28:21 pm »
I tried it with another used carb and got the same result. That had me thinking governor. But unless they are built different now I can see no evidence of one. Going to try a new carb today.

Offline Cut4fun

  • Administrator
  • Nitro Hotsaw
  • *******
  • Posts: 4045
  • Karma: 159
  • OHIO REDNECK
Re: Carb ?
« Reply #3 on: March 07, 2011, 12:34:04 pm »
Could be gov inside car.  Had 084 carbs that had some kind of limiter in them. Brass jet type thing inside the carb itself, that flooded them out like the outside brass gov we normally see on carbs.  JB  was used to block orifice ;)  has to be something better to use out there.
REDNECK Saw Repair

Offline Old Iron Logging

  • Nitro Hotsaw
  • *******
  • Posts: 1132
  • Karma: 81
Re: Carb ?
« Reply #4 on: March 07, 2011, 12:49:31 pm »
From this ill it appears to me that there is a governor under the idle adjustment screw. Am I reading this correctly? Look at part #s 17 and 33

http://wem.walbro.com/walbro/product.asp?CategoryName=944&Series=HDA&partnum=HDA-205-1&GroupName=Chain%20Saw&FamilyName=EMAK

Offline stihlbro

  • 4 cube
  • **
  • Posts: 70
  • Karma: 9
  • Location: virginia
Re: Carb ?
« Reply #5 on: March 07, 2011, 01:09:02 pm »
I've been looking at that too, it appears the hda series has the option of a governor.

Offline Old Iron Logging

  • Nitro Hotsaw
  • *******
  • Posts: 1132
  • Karma: 81
Re: Carb ?
« Reply #6 on: March 07, 2011, 01:12:03 pm »
I just looked the carb over again and see nothing on the outside.

Offline Cut4fun .

  • Administrator
  • Nitro Hotsaw
  • *******
  • Posts: 21879
  • Karma: 522
  • OHIO REDNECK Saw Repair Getter Done
    • Redneck Chainsaw Repair
Re: Carb ?
« Reply #7 on: March 07, 2011, 01:12:37 pm »
17=   Governor Kit   ???
REDNECK Saw Repair Getter Done

Offline stihlbro

  • 4 cube
  • **
  • Posts: 70
  • Karma: 9
  • Location: virginia
Re: Carb ?
« Reply #8 on: March 07, 2011, 04:25:50 pm »
I also see the circuit plate as a possibility. Fuel has to be feeding the engine to see 12000 rpm. Kinds sounds like a governor to prevent leaning out on topend. I don't see the low side delievering that much fuel. Does the 205c have the circuit plate?

Offline Old Iron Logging

  • Nitro Hotsaw
  • *******
  • Posts: 1132
  • Karma: 81
Re: Carb ?
« Reply #9 on: March 08, 2011, 02:36:49 pm »
Yes the 205 has a circuit plate.

 

Related Topics

  Subject / Started by Replies Last post
41 Replies
2398 Views
Last post February 10, 2020, 08:29:29 am
by Cut4fun .
5 Replies
585 Views
Last post May 08, 2011, 07:32:15 pm
by mweba
3 Replies
494 Views
Last post August 17, 2011, 08:19:12 pm
by Cut4fun
7 Replies
349 Views
Last post December 20, 2011, 04:49:14 pm
by mike84c
Stihl 041 Carb Problem

Started by Dh1984 « 1 2 3 » Stihl

22 Replies
1530 Views
Last post January 19, 2012, 12:42:39 pm
by Dh1984
13 Replies
3488 Views
Last post January 25, 2012, 07:21:50 pm
by Al Smith
5 Replies
749 Views
Last post February 21, 2012, 01:29:32 pm
by 660magnum
1 Replies
417 Views
Last post April 16, 2012, 04:52:37 am
by fordfairlane78
35 Replies
1067 Views
Last post November 11, 2016, 11:28:35 pm
by pete
3 Replies
270 Views
Last post June 30, 2015, 07:11:44 pm
by Jason K