OzVMX Forum
Clubroom => Tech Talk => Topic started by: John Orchard on September 05, 2014, 10:21:19 am
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Would anyone have an idea on what shops would carry small washers suitable for shimming carb needles, TD Hatrick may have them but I would feel a bit stupid calling up to buy just a couple of little washers. Maybe some local-type shop could have something?
Groove 3 is too lean and 4 is too rich :-)
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http://www.circlips.com.au/content.php?sec=distributors
most bearing supplies should have them
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Groove 3 is too lean and 4 is too rich :-)
Never seen one that sensitive to adjustment John :o
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Yeh my 2005 YZ125 had a carb design problem that Yamaha fixed on the '06 model, they reduced the number of venturi pilot outlets from 3 to 2 and ran a different needle.
Having the 144 kit fitted has made the problem a touch worse, a half mill shim will get it close enough until I stumble across a cheap '06 to '14 carb :-)
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Thanks pokey, I have an electronics shop 'Jaycar' down the road, I'll try them first.
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just wondering if there may be another reason that one clip groove should make such a difference!!, maybe a very worn needle jet [emulsion tube] where the needle runs--& maybe a worn needle too [combo], or idle mixture set way too rich & overlapping further up [as in] richening up on a closed throttle into a corner then having to clear, or needing a leaner cutaway on the slide. Or is it a carb [not sure what type] with big steps for one clip step. Thin a 36 bing [bung] i use has fairly large steps compared to mikuni etc. Sorry, don't mean to try & poke holes in your ideas--just tossing my ideas around [or was that just tossing lol?] Cheers.
Start again, even had a strange problem 20 years ago in bucket racing where [big ports & holes everywhere] & it blubbered uncontrollably just at the point where it got on the power [big power from a 100 lol] was rich symptoms [but wasn't] some smart arse said double up the reads coz they're fluttering at that point in the revs & bugger me 'they were'--absolutely fixed it on the spot. Had an RT2 reed block & cut off housing welded into a mudbug cylinder at a great angle--another failure but went like hell, till it blew!!. Cheers.
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KLR 650's use shims to adjust the needle.
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just wondering if there may be another reason that one clip groove should make such a difference!!, maybe a very worn needle jet [emulsion tube] where the needle runs--& maybe a worn needle too [combo], or idle mixture set way too rich & overlapping further up [as in] richening up on a closed throttle into a corner then having to clear, or needing a leaner cutaway on the slide. Or is it a carb [not sure what type] with big steps for one clip step. Thin a 36 bing [bung] i use has fairly large steps compared to mikuni etc. Sorry, don't mean to try & poke holes in your ideas--just tossing my ideas around [or was that just tossing lol?] Cheers.
Start again, even had a strange problem 20 years ago in bucket racing where [big ports & holes everywhere] & it blubbered uncontrollably just at the point where it got on the power [big power from a 100 lol] was rich symptoms [but wasn't] some smart arse said double up the reads coz they're fluttering at that point in the revs & bugger me 'they were'--absolutely fixed it on the spot. Had an RT2 reed block & cut off housing welded into a mudbug cylinder at a great angle--another failure but went like hell, till it blew!!. Cheers.
Interesting, thanks. I guess if Yamaha reduced the number of pilot outlets on the next model that maybe there's too much fuel at part throttle? (1/8th?), been going down on the pilot (from 40 to 30), going to try a 27.5 next, it still starts cold without the choke but bogs (lean stumble) on throttle part opening until been running a minute.
Changing the needle from groove from 4 (std) to 3 cleans up part throttle when it is warm, I'm just interested to see what 3.5 would be like.
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I recently got a pack of shims from a ebay seller in the USA. Has 0.25 ,0.5 & 0.75 shims. Is it a mikuni or keihin
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05 YZ = Mikuni TMX.
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05 YZ = Mikuni TMX.
Correct :-)
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You need a tmx-x off an rm 125 ;)
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Only thing I have in the garage are VM36 round slides and a PJ36 off a CR125. I'll live with it for a bit longer :-)
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http://www.ebay.com/itm/2005-Suzuki-Rm-125-Rm125-Carb-With-Throttle-Assembly-/261582148740?pt=Motorcycles_Parts_Accessories&hash=item3ce782d484&vxp=mtr
Cheap as
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try filing the back of the slide on your richer setting to let a bit more air in? or is that not achievable with that carby??
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http://www.exhaustgas.com/ProductDetail.asp?ProductID=1798&DepartmentID=10&CategoryID=61&MenuID=sub4&BasketID=&RepID=