Board index Flathead Power-Technical Questions, Answers, and Suggestions Evo's Thru 99 Super E Carb hassles

Super E Carb hassles

Moderators: Curt!, Pa

Post Mon Apr 14, 2014 3:40 am

Posts: 176
Location: Carmarthen, Wales, UK

I'm posting this on behalf of a good friend in Australia, hoping the collective knowledge can offer a solution; here it is in his own words. He has posted a video on You-tube describing the issue so feel free to comment on there if you wish, otherwise I'll give him the link to here.

"My S&S Super E carb has performed flawlessly for several years, kickstart only, with one issue. I replaced the throttle shaft and plate about 5yrs ago as part of a general overhaul of a tired carb, and ever since I CANNOT get the throttle plate to to return to its fully closed position *IF* the accelerator pump screw is even slightly ''on''.

So I have had the accelerator pump switched OFF. No squirt of fuel when I twist the throttle ... But the alternative is a high and erratic idle because the accelerator pump is ON thus the throttle plate does not shut.

I have lived with it, but now it bugs me and I want to sort it so I do have a working accelerator pump at the same time as a perfectly closing throttle butterfly.

I have cleaned the carb thoroughly (you can see how gunky it has become in 5yrs by looking at the throttle shaft along the plate, I will get a cotton bud into there to finish the job)..... checked the little balls and spring in the accelerator pump housing, the shaft and rubber boot are clean......what gives?

Any solutions welcomed. At this stage I feel like I will buy and install an accel pump rebuild kit, at least....

There is no issue with throttle cable adjustment, trust me. I have adjusted it 56 ways through Sunday....."

Thanks in anticipation for your help

72 Ironhead, goes better than it stops!



2005 XL1200R.... well ya gotta have a rat-bike!

Post Mon Apr 14, 2014 8:05 am
Pa Site Admin

Posts: 5547
Location: Ohio USA

Intake manifold leak ???

Post Wed Apr 16, 2014 2:56 pm

Posts: 150
Location: Carver, MN

I can't help but think that something in the accelerator pump mechanism (on the throttle shaft) is assembled incorrectly. To clarify, the " accelerator pump screw" as you refer to it, adjusts the stroke of the pump - it actually provides a stop for the pump rod movement. To disable the pump, you turn the screw all the way in. No where in the range of adjustment of this screw should it in any way effect the throttle plate's ability to close. Any chance the throttle plate is installed backwards? Could the spring on that end of the shaft be hooked incorrectly? I am not sure that either of these scenarios are even possible, but that is where I would start looking.

Pa, I suppose that what you suggest may be possible, but it would seem to me that disabling an accelerator pump would not mask an air leak. In fact, one would normally expect just the opposite.

Post Sat Aug 23, 2014 2:13 pm

Posts: 1
Seems to me the problem is throttle return spring. It's either missing, broken or installed wrong. It's the spring on the other side of carb shown in the video, behind the throttle wheel where the the throttle cable attaches. The accelerator pump spring will do the work of the throttle spring until the point that the accelerator pump mechanism hits the screw stop, then the throttle spring closes it the rest of the way. Your accelerator pump linkage looks fine, the problem is on the other side of the throttle shaft.

Post Sun Aug 24, 2014 11:22 am
Pa Site Admin

Posts: 5547
Location: Ohio USA

Could the throttle plate be installed incorrectly ? Most throttle plates are beveled on one edge and if that bevel is reversed the plate cannot close fully. Just a thought.

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