carburetor

[jerry potaracke 3]

can anybody tell me why my engine will only run with the choke closed . this particular carb seems a real pain.  i've left this carb in berrymans cleaner for three days and cleaned out with carb spay. i also put in a new kit with the idle screw at one turn out and the main screw at one and a quarter out  thanks and merry christmas and happy new year 

[ebinmaine 72,710]

Hi Jerry.

What engine and tractor?

 

1 turn isn't near enough for the larger engines.

 

I've had particularly temperamental carbs that I've cleaned out 2 or more times....

 

 

[lynnmor 7,824]

See you are kinda new here..... 

 

Soaking carburetors will help only those conditions where a gummed up condition exists.  Most likely you still have dirt that needs to be cleared, so take the carburetor completely apart and try again.  Do not probe jets with wire as that will alter the flow rate if they are scratched, use a bristle from a paint brush.  Blast thru all passages with carb spray that has a straw.  Some carbs have a welch plug that needs to be removed to get at some small passages.  I'm not sure exactly which carb you have, a photo or link would help. 

[pacer 3,177]

1 hour ago, jerry potaracke said:

and the main screw at one and a quarter out 

Thats not enough --- most carbs are gonna end up with the jet somewhere close to 2 1/2 turns. Try yours at 2 1/2 and with the throttle open vary that back & forth. With you having to run with choke out obviously means a shortage of fuel and the fuel has to come through the that opening in the jet ... sooo opening it up should help - we hope!

[jerry potaracke 3]

2 hours ago, ebinmaine said:

Hi Jerry.

What engine and tractor?

 

1 turn isn't near enough for the larger engines.

 

I've had particularly temperamental carbs that I've cleaned out 2 or more times....

 

 

this is a wheel horse d160  twin twin automatic      the engine is a 16hp onan  b43m gao16 3602a 

[ebinmaine 72,710]

4 minutes ago, jerry potaracke said:

this is a wheel horse d160  twin twin automatic      the engine is a 16hp onan  b43m gao16 3602a 

 

Ok yeah....

See what @pacer wrote just above.

Definitely needs more turns out on the needles....

 

[ZXT 2,401]

1 hour ago, pacer said:

Thats not enough --- most carbs are gonna end up with the jet somewhere close to 2 1/2 turns. 

 

 

It's obviously extremely lean. Use the screw turns suggested here as a baseline and you can fine tune it by ear from there. 

 

Also, if it still doesn't run right when you're done. torch tip cleaners work excellent to clean out passages. You might have flow through a passage, but if there is buildup reducing the flow it will cause issues.

 

Oh, and to ! Any photos of your tractor?

Edited December 27, 2019 by ZXT

[Ed Kennell 42,028]

Could be excess air leaking in through a bad gasket or worn throttle shaft bushing.    

[WHX?? 51,773]

and happy holidays to you too Jerry....

If this a carb that we're thinking it is the very top screw goes all the way down in the bowl. It has small holes in it so check those also. New fuel lines and filter may help too. Maybe getting crap in it from there? 

Edited December 27, 2019 by WHX24

[stevasaurus 23,281]

If it runs with the choke closed, you are usually sucking air from somewhere.  

[lynnmor 7,824]

If you have the Marvel Shebler carburetor, lightly seat the mixture screws and then turn out the idle mixture screw 1 turn and the main screw 1-1/4 turns.  Until you can describe or show a photo of the carburetor. it is hard to help.

[wallfish 18,117]

You got some good advise already but also keep in mind, every engine is different and the factory settings are only a starting point. Final adjustments should be done with the engine running and warm. I'm sure the engine manual will cover the proper procedure for adjusting those settings.

[pacer 3,177]

Gonna throw a bit more  ---- fuel? on this problem. But may as well get it said with a new owner here--- the Onans are notoriously finicky to tune, obviously more so with age, so try and keep your patience in check.

 

I also have a B43 Onan and when I first got it and started to get it to run right  ---- well ... I almost gave up and was seriously considering a replacement when I FINALLY hit on the problem -- bad condenser! Geeeez it was bit$#% though!