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Discussion Starter · #1 ·
So while cleaning the carbs I noticed my acccelerator pump barely moved up and down (less than a MM), and I noticed that it's default position was touching the metal stop connected to a spring/nut combo.

Questions:

1. What does this rod do?

2. Should I adjust the stop so it has 3 mm of play, or does it pull downwards up to 3 mm?

3. Does anyone want a throttle stop screw? I apparently bought two.
 

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So while cleaning the carbs I noticed my acccelerator pump barely moved up and down (less than a MM), and I noticed that it's default position was touching the metal stop connected to a spring/nut combo.

Questions:

1. What does this rod do?

2. Should I adjust the stop so it has 3 mm of play, or does it pull downwards up to 3 mm?

3. Does anyone want a throttle stop screw? I apparently bought two.


Here is a snippet from the manual on how it should be adjusted.

 

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Also, from this pic you can see it's just a tiny plunger. It's not really intended to move very far, though I can't remember how far mine moved.



 

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So does opening the choke just push down on the accelerator rod?
As I remember, no. Turning the Throttle Cam should push on the Accelerator Pump Rod... BUT, the Choke does slightly turn the throttle cam, which should just bump the Accelerator Pump Rod. Is that the action you are seeing?



The Accelerator Pump Rod should get pressed when you roll on the throttle. The faster you roll on the throttle, the faster it gets pressed down and it pushes more fuel into the crabs through the front spray jet (in front of the throttle butterfly valves). This keeps the engine from briefly cutting out on a quick roll of the throttle.

 

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Ye I wondered why some CX models had the AC pump. I have it on the wifes CRF150R MX bike and for sure the way they rev you need it on the single cylinder....but the CX?



Mine does not have a AC pump and the throttle response is excellent, no bogging at all so why did the japs fit the AC pump to these motors?
 

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The accelerator pump was added when they changed the carb design so it would run even leaner, so much that it was necessary to add one to prevent the engine from bogging down when you made a large throttle change. At least that's what I've read in some old posts.
 

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Accelerator pump not working

I’m looking for the same answer. When I turn the throttle cam the accelerator pump on my newly rebuilt carb moves only slightly. If I take a pair of pliers and move the plunger myself it moves 4 to 5mm witch is what I expect it is supposed to do. On the very end of the accelerator pump actuator (that’s what I’m calling it) there is a spring that helps force the actuator up when the throttle cam is rolled on. There is a tab at the very end witch I suspect I can bend but it looks to be straight so I’m reluctant to bend it.
Another issue is when I reassembled the “Rod set Pump” the thing that moves the accelerator pump and is also a part of the fast idle adjuster (my words) when I tighten the bolt that hold the 2 parts on and the spring in between them tightening the bolt locks the whole mechanism in place mobilizing it. I’m not sure in what order washers may go or if it needs washers at all.
So my question is what is the proper way to assemble the “Rod pump set” and how do I get it to move the accelerator pump fully?
 
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