copemech Posted April 29, 2009 Report Share Posted April 29, 2009 Sounds like what you found could be IT, yet not sure where IT came from. As there are only two basic ways IN to the bowl, fuel supply or vents, and even folks with dellortos (very good banjo screen) get stuff in there, so what does that tell you(those vents BREATH). I would not run the K carb without an inline filter, yet just how good they are I am unsure. I do not know what fuel hose you are useing, but the factory rubber never lasted for me, always split, and for the last 5 or so years I have run the green TYGON hose which seems to last a couple years, and it is pliant enough to adapt from the 3/16 tank outlet to a 1/4 fuel filter. This flexability does not allow it to hit the muffler, as it will not take the temps, but with a careful loop in the routing , this has never been an issue. Quote Link to comment Share on other sites More sharing options...
neo Posted April 29, 2009 Author Report Share Posted April 29, 2009 This is double interesting (and confusing) Cope. Ok logicality the bowl would only get contaminates from the fuel line or the vents but.... 1. My fuel line is black but still in very good condition....but I'll fit a new one anyway. 2. My vents are piped high, then low (down wide hoses) all the way down to the delta link...there just ain't enough vacum to suck anything up those tubes. 3. Shiny blacks and reds didn't come from the ground around here. 4. The particles are way too big to have passes through the Sherco filter in the tank. 5. I also found one shiny black particle on the intake side (before the slide) of the carb. So logicically it looks like the Jitse air filter to me....but it's illogical how these bits ended up in the bowl The 250 ran great this afternoon. But I didn't have enough time to fine tune the airmix before the heavens opened up and brought my ride to an abrupt end Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
copemech Posted April 30, 2009 Report Share Posted April 30, 2009 Does seem a bit of a mystery, yet I still would run an inline filter, as that screen in the tank is questionable with relation to what it would take to plug the pilot jet? Secondly, the up, over and down theory on those vent tubes just does not work for me. You see, if ANY fluid is caught in the tube, almost like a bubble in a straw, it causes an imbalance in bowl pressure relative to the ambient. It is sensitive beyond belief! This is the reason I doubt you will see any hoses on any PRO bikes, as they would even prefer to clean the carb as daily maintenance over the difficulty the hoses can cause. Another reason why dual vents offer an advantage, but I believe Sherco removed the hoses on them from the factory in later years, due to problems. Best left off! Although I still run two very short tubes just for deflectors. Quote Link to comment Share on other sites More sharing options...
neo Posted April 30, 2009 Author Report Share Posted April 30, 2009 Hi Cope, Maybe we live at different altitudes or something but since fitting the tubes (to both of my vents) I Quote Link to comment Share on other sites More sharing options...
copemech Posted April 30, 2009 Report Share Posted April 30, 2009 Well Neo, you may well have a good arrangement here, although I have not quite totally envisioned what you have done. Main point being that most folks have no idea just how critical this is. Fact is that I never found a hose that would work on the right side with a K carb as the relation to the muff was just too close on my bikes. The left vent had to be drilled out in order to accept any type of hose that did not pinch off due to the radius of the bend. Your CRAP in the bowl still explains a lot, and once again one is often surprised at what he finds, if he is lucky enough to ever see it! I admit that there have been times I never actually found anything! More than not! Quote Link to comment Share on other sites More sharing options...
neo Posted April 30, 2009 Author Report Share Posted April 30, 2009 I admit that there have been times I never actually found anything! More than not! Me too I'l try and post some photos of my hose setup. Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
neo Posted May 1, 2009 Author Report Share Posted May 1, 2009 Hi Cope, On this first photo you can see the smaller tubes going into the wider ones. And can also see the sping I use on the spring I use to stop the RH vent tube kinking and protect it for the heat. On this second photo you can see how I keep that RH hose up high. Let me know what you think? Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
shercoholic Posted May 1, 2009 Report Share Posted May 1, 2009 Very tidy setup to keep the exhaust heat off the breather hose. Nothing like stating the obvious but just in case ....is that inlet manifold hose clamp just moved out of the way for carb disassembly? Quote Link to comment Share on other sites More sharing options...
neo Posted May 1, 2009 Author Report Share Posted May 1, 2009 ....is that inlet manifold hose clamp just moved out of the way for carb disassembly? Yep...I was half way though putting the whole thing back together when I took the photos....but it's good you have such a sharp eye Shercoholic Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
copemech Posted May 2, 2009 Report Share Posted May 2, 2009 Well it looks like it will work well enough to me, primarily due to the dual vents and the ability for any fuel to run back down, as compared to a down then up loop which can trap fuel in the lower section. The smaller hose you have there does look like the green Tygon F-4040 in the pics. It does discolor over time but stays pretty flexable. Only problem that comes to mind with the arrangement would be in a muddy trial and the ends of the tubes getting packed down near the ends, or a deep water crossing if they are run all the way down near the skidplate. Now is that the OKO? Looks as though you may have had to devise a fitting to tap into the left side vent. The nipple casting was there on my K carb but not drilled. Pics I have seen of the OkO did not show it. Have you tried that 24 yet? Quote Link to comment Share on other sites More sharing options...
neo Posted May 2, 2009 Author Report Share Posted May 2, 2009 The smaller hose you have there does look like the green Tygon F-4040 in the pics.Only problem that comes to mind with the arrangement would be in a muddy trial and the ends of the tubes getting packed down near the ends, or a deep water crossing if they are run all the way down near the skidplate. Now is that the OKO? Have you tried that 24 yet? Actually it's a Tygon pink that came with the OKO kit. I rarely ride in mug...and never in water. It's my Keihin 28...It was setup the wrong way round when I first got it. So I had to drill the second vent and idle screw out anyway. And since then I have re-drilled both vents about as large as I dare. Oddly enough the OKO 24 has only one vent but never suffers from any breathing problems. And I can't remember the last time I adjusted the airmix on that Carb. No sorry Cope I haven't tried out the OKO 24 on the 250 yet. Because when my bikes running right I find it hard to mess around with it. But I hope to try the OKO24 out in the next few weeks. Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
copemech Posted May 3, 2009 Report Share Posted May 3, 2009 Neo, although some operate in such dry conditions, most are not that fortunate. Your basic setup though, reminds me if the Mikuni fix on the Beta's for the p***ing and venting which did seem to work. They were just both run "up" then "T" together with a down curve that just exited near the top rear of the motor. Just a thought! On the 24mm topic, you know, for whatever reason, my 125 was never picky with the dellorto, it just ran. I think with half the displacement, they are just half as finiky! Quote Link to comment Share on other sites More sharing options...
neo Posted May 3, 2009 Author Report Share Posted May 3, 2009 Hi Cope, I originally set the tubes high-then-low because one day I was doing a very steep decent (which I came to a stop on) and noticed petrol pouring all over the front mudguard. And I realise I had been losing a lot of fuel while riding with this carb. Because on a very steep decent the angel of the carb is virtually horizontal. I've taken the wide tubes right down past the bash plate but they don't have to be that long. I've never seen any fuel coming out of them. Even after many foreword/backward crashes. But after the high-then-low part the shorter the tubes are the less likely the mud can get up to them. I reckon your right about the 125 too... it's and engine that's too good to be true. Best of balance. Neo Quote Link to comment Share on other sites More sharing options...
clav3 Posted May 3, 2009 Report Share Posted May 3, 2009 (edited) Hi Neo I'm from Brisbane and having the exact problem with the PWK on my 290. Carby perfectly clean, neadle and seat looks brand new, checked engine and manifold for air leaks, installed a new pilot jet and reeds, cleaned tank, fuel tap, air filter, breather hoses, tryed different fuel, made sure tank was venting. I have been running, for about a year, wet or dry, hot or cold, a 42 pilot jjj needle second clip from bottom jitsie aie screw 1 1/4 turns out and have been turning back in 1/3 turn for shaily hillclimbs. Now just to get it to idle 45 pilot, Air 1/4 out, and jjh needle (next richer) second clip from bottom. This is a big change all of a sudden and still slightly hunts on idle. It also runs richer when pointing downhill and leaner pointing uphill which makes me think there might be an air leak in the carb. It has gone lean before to the extent of turning the air screw in a full turn to get it to idle and normally just clean out the carby and its fine. Brett from Motocentral suggested a worn piston may cause hunting for fuel at idle. Yesterday I put the Dellorto back on to rule out an air leak or piston problem. 33 pilot 3 3/4 turns out and standard needle on bottom clip. The standard config when the bike was new was too lean and had engine ping in the mids. The bike runs perfectly! And a bonus, now the mapping switch now gives two very distingtive and usable modes. (I know what you're thinking Cope) So it seems there is a problem with the keihin. The is two non tamper screws holding the center of the carby in place with an o ring in there that I'm told is non serviceable because nobody has ever had to. I've bought a bit for these screws but finding it hard to bring myself to take it apart fearing I might on the wrong track and stuff the craby for good. Neo I'm a crap typer. Thats why I don't post many times. If you want to email me your phone number emty1@optusnet.com.au I can understand if you dont want to. Edited May 3, 2009 by clav3 Quote Link to comment Share on other sites More sharing options...
copemech Posted May 4, 2009 Report Share Posted May 4, 2009 (I know what you're thinking Cope) Yea, try a 36 or 38 pilot, put the needle back in the 3'rd groove and ride it! I will restate my opinion, the Kiehins can be a better mixer and higher performer, yet a pain in the butt that most do not want or need! Quote Link to comment Share on other sites More sharing options...
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