DD13 Carb adjusting clarification needed
Posted August 22, 2011 - 02:17 PM
I need some clarification on adjusting the carb. In trying to adjust the jets I found that the idle screw was effecting the WOT setting. I did not think that the idle adjustment is supossed to effect WOT. ANyway I did get them "walked" in to where it would idle and WOT without hesitating.
In the manual, it says to adjust the idle screw then to adjust the idle stop screw for 1300RPM. Then to adjust the main jet.
SHould I back the idle stop screw all the way out untill the butteryfly is closed, then adjust the idle screw.?
Its so much easier to explain this in person than tryingt to type it out. I hope its not too confusing.
Posted August 22, 2011 - 02:40 PM
Posted August 22, 2011 - 04:52 PM
no idea why. but hey, they are what they are, and work good once set properly. i have had better results switching the dd out for a carb off of a briggs boxer twin (can't remember make or model #etc off hand). with the small effort it takes, the power output seems to go up a little , and the engine runs and revs up ALOT smoother than the dd can accomplish. even found the onans can idle smother at the proper (1200rpm) idle. less shaking.
Posted September 11, 2011 - 07:02 AM
This is definatly a learning expeirience for me. After the inital post in this thread I finally had a chance to give the D160 a workout. At idle it sounded great and responded well. When i put it underload it had no power, I adjusted the jets until I could get some performance out of it but still not much power. Mowing grass at anything but a crawl would bogg it down to a stall. So I found some time tear back into it this past friday. I used propane and checked for leaks over the manifold and carb and i could not find any. I pulled the carb and intake and looked for any problems and still could not find any. I disassembled the carb and threw it in the ultrasonic cleaner for 3 hours and then rinsed, dryed and checked the passages. Everything was good. I checked the carbs mating surfaces for flatness with a straight edge and could not find a problem. I decided to try the sandpaper and block to just see if it was true. I used 600 grit paper and a 12 sanding disk. By hand I just gave the lower half a few strokes to see if there were any high spots. Sure enough I found a very low spot on the venturi face where the two halves meet. After about an hour both halves are flat and true again. I reassemble and reinstall it all on the tractor. I get it adjusted and it is reponding like it should, then i run out of play time. Saturday I get a chance to try it out after I get the rest of the tractor back together. WOW what a difference, Thats what a properly functioning Onan sounds like. No bogging, no spitting, no popping. just smoothness. I mow around the garden and the back "feild"about 45 minutes total. I go to mow around the little pond I have and she just dies. Sounds like I am out of gas, nope still has some. Play with choke a little and get her going and head back to the shop. I let it cool down and try again. My exact same symptoms are back, its running the same way as before. I just have to walk away for the day. I have a few hours this morning so I will take it all back apart and see what went wrong. Its pretty disgusting when you know how well it will run and then at the drop of a hat it decides that she wants more attention. I am not going to give up on her. I will keep playing with her untill she decides that she has been satisfied with the amount of attetion she wants.
Posted September 11, 2011 - 07:21 AM
Posted September 11, 2011 - 09:27 AM
I was suspecting that the carb halves warped again but I found no signs of it. When i snaded it again tosy everything was good. Then I susupected that the gasket may not be sealing properly so I cut one out that was thicker. The only thing I fmight have found was that when I took off the intake, the bolts did not feel as tight as they did yesterday. I had made new gaskets for the intake yesterday but I did not use RTV on them. Like I said, nothing definative so i just shotgunned it all. Before it wouldnt run right, after it did. At least for now.
Maybe I will get to mow the yard today and give it a good work out.
Posted September 18, 2011 - 05:44 AM