cheesepreetza Posted July 2, 2015 Report Share Posted July 2, 2015 (edited) I was driving home from a rainy practice ride this past weekend, (bike was in the back of a pickup) with a new to me 2011 Sherco 2.9. When i arrived home i attempted to start the bike, no go, so i put a new plug in and went ahead and cleaned carb. In the process i found some interesting items i'd like to get some more info on. Carb had very little water in it, air box is a terrible design! how did these bikes make it threw 2010/11 SSDT?! So the needle seat fell out into my hand, i would assume these are a press fit, not jiggle around. Only goes in one way? The float bowl tube is bent on a 45.0 with a flare on the end, guessing this is some sort of a mod? after cleaning and putting back on the bike, idles perfect. Wack the throttle and a big lean bog! WTF. i changed nothing but cleaning it. so i put around the yard, accelerate slowly 1/2 throttle and it burbles and coughs as if the choke is on. So i go ahead on throw the stock Dell'orto on that the previous owner left for me. It runs a tad rich but no hesitation, But the first thing i noticed was how stiff the kicker was with the Delly on. HOLY @#$! felt like a brand new bike. I think i will raise the needle one clip and see how it runs from there. Why would the Keihin affect compression? Edited July 2, 2015 by cheesepreetza Quote Link to comment Share on other sites More sharing options...
lineaway Posted July 2, 2015 Report Share Posted July 2, 2015 Someone really screwed up that carb. Have someone that knows Keihin`s show you a proper one. Quote Link to comment Share on other sites More sharing options...
dan williams Posted July 2, 2015 Report Share Posted July 2, 2015 Did you clean it out with compressed air. The Keihin has a tendency to get a water bubble in the tiny bleed hole in the throttle body. The only way to clear it is with compressed air. The vent tube is at an angle which makes putting the float bowl on a pain. The technique is to slide it on while holding the carb upside down. By needle seat do you mean the needle jet? Quote Link to comment Share on other sites More sharing options...
cheesepreetza Posted July 2, 2015 Author Report Share Posted July 2, 2015 Dan, i blew it out with compressed air and carb cleaner, it was spotless, i could see through all the jets. Throttle body? you mean slide body? i only see two on the out side for venting, both were free and clear of crud. The Needle seat (i think is that its called) is in the picture above. I can remove it quite easily and its jiggles around some. One would think it would be an interference fit. Quote Link to comment Share on other sites More sharing options...
tony27 Posted July 2, 2015 Report Share Posted July 2, 2015 The piece you're showing is the extension / shroud for the emulsion tube / needle jet, it shouldn't come out. You asked a question earlier about which way up it should sit, not easy to measure but mine only sticks up between 1 & 2 mm so I think you may have refitted it upside down Quote Link to comment Share on other sites More sharing options...
lineaway Posted July 2, 2015 Report Share Posted July 2, 2015 (edited) Yes Dan, he is talking about the needle jet. It also sounds like someone flattened the end of the vent tube. PS after reading your other thread, I would try a 48 - 50 pilot jet. Edited July 2, 2015 by lineaway Quote Link to comment Share on other sites More sharing options...
cheesepreetza Posted July 2, 2015 Author Report Share Posted July 2, 2015 (edited) Thank you for the replys guys, Lineaway, the vent tube is not flattened or plugged, it has a 48 pilot currently. Tony 27, Interesting, well the other way the needle jet extension has a hole in the one end, but it will not budge to fit in there. flip it other way(like in picture), it jiggles around. Leads me to believe when the bike is on a incline (climbing,mid wheelie) only at half throttle to WOT it would load up because the needle extension is lifting with the needle? Edited July 2, 2015 by cheesepreetza Quote Link to comment Share on other sites More sharing options...
sirdabalot Posted July 2, 2015 Report Share Posted July 2, 2015 Does the needle jet extension not have a half section cut out across the diameter, which should be positioned towards the airflow. Quote Link to comment Share on other sites More sharing options...
lowbrow Posted July 2, 2015 Report Share Posted July 2, 2015 From the photo it looks like the needle valve has been inserted from the venturi, when it should've been fitted from beneath, before the atomiser/main jet holder which holds it firmly in place. Make sure you install the needle jet the correct way up too. Quote Link to comment Share on other sites More sharing options...
dan williams Posted July 2, 2015 Report Share Posted July 2, 2015 There is a TINY hole in the bottom of the bore in line with the needle jet that sometimes gets plugged by water. Usually twice a year I disassemble my carb, including the stack in the float bowl that is held on with T20 security screws, and blow out all the passages. I agree it sounds like your jet assembly is put together a bit wrong. I think the main jet holder is supposed to hold the needle jet in place from the bottom. The PWK Keihin is quite a good carb but like any of them, get one bit a little out of place and the bike will run but run lousy. Quote Link to comment Share on other sites More sharing options...
steve_earle Posted July 2, 2015 Report Share Posted July 2, 2015 Lowbrow, Is spot on, The needle jet is supposed to go in from the bottom. Search for an exploded diagram for the carb and you will see what way round everything goes. Quote Link to comment Share on other sites More sharing options...
cheesepreetza Posted July 6, 2015 Author Report Share Posted July 6, 2015 Yup, Lowbrow was correct. It was after i looked for a micro-fiche for the Keihin. I have 36mm Keihin on my sx 250 and it doesn't have that needle seat at all. So i was unsure of how it assembled, it didn't seem right to jiggle around. Thanks for all the assistance. Quote Link to comment Share on other sites More sharing options...
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