Carburetor adjustment SS,I played with the 3 adjustment screws the bike runs but its missing and bogging out. Can you help me?????????????
I assume that you're working on an S&S Super E. This carb is a bit much for an old Ironhead but I've seen plenty of them on these old machines. I think the Ironhead engine is the prettiest engine Harley ever built. They are also one of the most aggrevating as well.
On your S&S, the best jetting I've found for them is a #26.5 slow jet with a #68 or 70 main jet.
You must tune a Super E model the same way you tune a Super B model. The only difference between the two models is the "B" model does not have the accelerator pump. When you tune an "E" model, disable the accelerator pump by backing out on the screw that controls it. With the accelerator disabled, procede to tune your carb by turning the idle mixture control screw unwards until it stops and back out on complete turn. Now rev the engine, does it rev clean or does it bog? If it bogs, come out another half turn and rev the engine. It is better or worse. If you still can't tell, come out half turns at a time until you can tell it's either better or worse. By turning the screw out, you're adding more fuel. So if it revs better with the screw three turns out, you need a richer slow jet. If it gets worse, reset it to one turn out and start inward. If it gets better going inward, go to a leaner slow jet. Once you change the jet, go back to one turn off the bottom on your idle mixture screw and try it all over again. Eventually, you will get the slow jet right where you need it to be.
Now, tuning the high or main jet will have to be done on the road. Find you a long uphill run somewhere. With the bike in high gear, roll the throttle on wide open going up the hill. If the bike spits or sputter back through the carb, you're way lean. If it starts to pull back off on the throttle about an eigth of a turn and see if it pulls better. If so, you're just a little lean. If it feels sluggish or black smoke is coming out of the exhaust, you're too rich.
Once you get these areas worked out, go back and add your accelerator pump back in. Take it on the road and roll the throttle on. Does it bog or blow black smoke. Turn the screw one half turn at a time. If it gets worse, go the other way half turn at a time. Be careful not to get it too rich on the pump shot. Most riders do get the accelerator pump too rich. Have someone ride behind you watching for the puff of black smoke.
You can download the installation instructions at the S&S website. Go to the "technical" section and then to "installation instructions". These instructions tell you everything you need to know adjust your carb and then some.
One word of advice on your Ironhead. If you are running open drag pipes, you can tune your carb till you're blue in the face and your bike will have a 'dead spot' at about 50-60 mph somewhere. This is because you have no backpressure on your exhaust. To get the backpressure you need while keeping that bad sound you like, drill a hole in the backside of your drag pipes so that you can add a 1/4" X 1 1/4" bolt about an inch or inch and a half into the pipe. Most drag pipes have a hole in this area for the bolt that holds the baffle in. Look at another set until you find one with the hole for the baffle retaining screw. Drill your pipes the same way. Put the 1/4" X 1 1/4" screw into the pipe and put three nuts on the bolt inside the pipe. Make sure you get them all tight. This will usually put just about the right amount of backpressure on your exhaust to cure the "dead zone". Hope this helps. Good Luck!
Apr 02, 2010 |
Harley Davidson XLH 1000 Sportster...