User Login    
 + Register
  • Main navigation
Login
Username:

Password:


Lost Password?

Register now!
Fast Search
Slow Search
Google Ad



Browsing this Thread:   1 Anonymous Users



« 1 (2)


Re: DCH-306 Carburetor
Moderator
Joined:
2001/5/3 7:04
From 48 North
Group:
Registered Users
Contentmaster
Usermaster
Posts: 31575
Offline
$30 good deal for a clean rebuild able carb. My only advice is check for radial play of the throttle shafts - there should be none. If they are loose it wreaks havoc with low-throttle air/fuel mixture.

Posted on: 2014/2/12 7:27
Transfer the post to other applications Transfer


Re: DCH-306 Carburetor
Not too shy to talk
Joined:
2014/1/9 3:07
From Nebraska
Group:
Registered Users
Posts: 23
Offline
It warmed up today so installed the carb on the engine. After it warmed up I got the engine to idle real good. But when I advanced the throttle to fast idle or higher the engine will start to miss and stall. If I close the choke to about 90-95% it runs OK. So the fuel mixture is too lean. Same problem as before with the original carb. The fuel level in the sight glass stays right on the dot during this time so the carb is not starved for fuel, I'm at a loss. I could install a larger primary main jet and see what happens.

Posted on: 2014/2/19 6:55
Transfer the post to other applications Transfer


Re: DCH-306 Carburetor
Moderator
Joined:
2001/5/3 7:04
From 48 North
Group:
Registered Users
Contentmaster
Usermaster
Posts: 31575
Offline
Too little fuel causes lean. But more common is too much air.

If there is an air leak, it causes the air/fuel mixture to go lean. Check all the hoses, especially the one to the distributor (plug it, it, will run OK with it plugged).

Posted on: 2014/2/19 7:39
Transfer the post to other applications Transfer


Re: DCH-306 Carburetor
Not too shy to talk
Joined:
2014/1/9 3:07
From Nebraska
Group:
Registered Users
Posts: 23
Offline
I've already checked the vacuum advance line. I sucked on the hose going to the distributor and the advance works and holds. No leaks. Did the same to the choke unloader dash pot and it moves and holds. No leaks. Now that the engine runs smooth at idle should show no vac leaks. There are five functions to a carburetor. Idle, above idle to max throttle, power, accelerator pump and choke. Something is screwey when an engine idles but needs 90% choke to run above idle.

Posted on: 2014/2/19 16:35
Transfer the post to other applications Transfer


Re: DCH-306 Carburetor
Moderator
Joined:
2001/5/3 7:04
From 48 North
Group:
Registered Users
Contentmaster
Usermaster
Posts: 31575
Offline
Agreed. Have you checked to see which jets are actually in the carburetor?


> Now that the engine runs smooth at idle should show no vac leaks.

A common thought but not entirely accurate. Vacuum leaks can occur above idle. Besides the two diaphragms you mentioned (advance and choke unloader) there are even more on some A12s including EGR, spark control, heated air cleaner, throttle opener, brake booster, altitude compensator, etc.

Being as your engine is not powering a car, it may not have some of those.

Posted on: 2014/2/19 22:16
Transfer the post to other applications Transfer


Re: DCH-306 Carburetor
Not too shy to talk
Joined:
2014/1/9 3:07
From Nebraska
Group:
Registered Users
Posts: 23
Offline
My original carb did not have the anti diesel cutoff, nor did the replacement. I believe that was for 1972 model only. It does not have any of the other add ons you mentioned. Yes. as mentioned previously all jets and bleeds are correct per the spec sheet.

Yesterday, I disconnected the throttle link arm to the auto choke and rotated the choke housing so the choke was just fully closed. Started the engine and the unloader opened the choke to the recommended opening. The engine now runs great at idle and high speed with choke about 90% closed. So I guess I will leave it that way for now. Not sure how the engine would performed using the power, accelerator, or secondary mode but since I don't need that it won't matter. As I said earlier the engine only needs to idle or mid throttle for working the 8000 lb. winch and the 2 gpm hydraulic pump.

Posted on: 2014/2/20 17:10
Transfer the post to other applications Transfer


Re: DCH-306 Carburetor
Not too shy to talk
Joined:
2014/1/9 3:07
From Nebraska
Group:
Registered Users
Posts: 23
Offline
I should have also said I disconnected the 12V to the choke so it is inoperative.

Posted on: 2014/2/20 17:32
Transfer the post to other applications Transfer



« 1 (2)



You can view topic.
You cannot start a new topic.
You cannot reply to posts.
You cannot edit your posts.
You cannot delete your posts.
You cannot add new polls.
You cannot vote in polls.
You cannot attach files to posts.
You cannot post without approval.

[Advanced Search]