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Installing a Genesis Carburetor

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Written by Randy Fox (randysgym)   
Sunday, 06 September 2009

Connecting the Throttle Cable/s

Once the carb body is installed, ensure the throttle cable is connected to the hand grip and fed through the guide at the front of the fork-tree and back through the cable guide near the frame neck and back to the carb area. If you will be using a throttle return cable (not necessary), do the same check for this cable also.

The instructions below apply to the throttle PULL cable, not the throttle RETURN cable, except where otherwise noted.

First, loosen the cable length adjuster (at the end/s of the cable) as much as possible, allowing the most inner cable to be exposed.

Now, since the Genesis carb comes with its own cable end-barrel, you must cut the stock end-barrel off the inner cable. That's right; it's going to feel like you're destroying your throttle cable! To do this, pull the inner cable while pushing on the outer cable-casing, to be certain the inner portion is pulled out as far as it will go.

Next, measure a distance on the inner cable, 3" from the end of the outer cable-casing. Mark it. Then using sharp wire cutters, cut the inner cable off at your marked spot. See photo below.

yamaha road star roadstar, genesis carburetor cable

Next, insert the freshly cut inner cable end through the brass fitting of the carb's top plate, nearest its center. Then press the outer cable end-fitting into the carb's brass fitting. The fit should be snug; in fact, it might be very snug. Be sure the cable's end-fitting fully seats into the top plate's brass fitting.

OK, now install the inner cable's end-barrel. To do this, pull the inner cable while holding onto the top plate to be certain it is pulled through as far as it will go without excessive force. Then measure and mark a point on the cable, 2 1/4" (57mm) from the underside of the top plate. See photo below.

yamaha road star roadstar, genesis carburetor cable

Next, be sure the set screw on the end of the P.S.I. supplied cable end-barrel is loose enough so that you can slide it onto the cable. Then slide the barrel onto the cable and over the mark you made. Moderately tighten the barrel's tiny set screw using a 3/32" Allen wrench.

Image

Now would be a good time to solder the end of the inner cable, if you want to do this. Doing so will prevent the cable end from fraying -- a good thing. Just be sure you don't leave so much solder on the cable that it becomes difficult to slide the Genesis end-barrel over it. Warning: A growing number of cable manufacturers use a special lubricant impregnated into the cable. The heat from soldering could destroy lubricant at the cable end, and perhaps also catch on fire. Use minimal heat, and work quickly.

OK, now for a cable test fit...

Install the slide spring over the end-barrel, up the cable, and onto the brass fitting on the underside of the top plate. Be sure you orient the spring so that its 'tang' end is not the end toward the top plate. See photo below.

yamaha road star roadstar, genesis carburetor slide spring

Next, compress the slide spring against the top plate. Compress it enough to expose the cable's end barrel plus about an inch of cable. This may not be as easy as it sounds; the spring is unwieldy.

With the compressed slide spring and top plate in one hand, hold the carb's slide in the other hand (or get someone to help you), and orient the slide so as to insert the cable's end-barrel -- with its set screw end away from you -- into the slide's 'barrel retainer hole' (the circle). Then lay the cable into the cable channel, and compress the spring a little further, as needed, to get it lined up with the 'slide spring guide hole'. As you do this, rotate the spring to orient its tail-end 'tang' in line with the cable channel. Finally, release the spring into the 'slide spring guide hole', while coaxing the spring's 'tang' over the end of the cable end-barrel. Whew! See photo below.

yamaha road star roadstar, genesis carburetor

Now insert the slide in its track in the carb, being careful the metering needle enters its nozzle hole without resistance. Then push the top plate down into place, and screw it fully down. No need to torque it down, yet though.

Check the slide operation, and the free-play (slack) in the throttle cable. Play with the cable adjustment nuts to remove any slack from throttle operation and achieve proper slide control. The slide should drop to its idle-stop when you release the handle grip, and the slide should rise to the roof of the carb throat when you twist the handle grip fully. There should be precious little free-play at the close-throttle (idle) position.

If the cable adjustment nuts are not able to achieve good throttle operation, you will have to adjust the end-barrel up or down as needed. If the slide does not drop all the way, the barrel must be lowered down the cable. If the slide does not raise all the way, the barrel must be raised. If the barrel has been raised or lowered, you must go through the test fitting process again.

Once you are happy with the throttle/slide operation, unscrew the top plate, and remove the slide. Then remove the spring and the cable from the slide.

Next, note/mark the final position of the cable end-barrel, and unscrew and remove the end-barrel's set screw completely. Dab a small drop of RED thread-lock liquid on the screw threads. Finally, position the barrel to its final place on the cable again, and screw in the set screw very firmly.

Now reassemble the cable and spring into the slide, and insert the slide in its track in the carb once more (being careful to guide the delicate metering needle into its nozzle). Then screw down the top plate. Torque the two top screws to 6 ft-lbs (60 in-lbs; not too tight).

Finally, if you are keeping your throttle return cable, connect it to the carb's top plate. It goes into the brass fitting that sits to the right. Note: I'm not sure how it gets secured, as I did not use it. Refer to the Genesis installation instructions from P.S.I, or call them directly.

 
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