October 26, 200916 yr Author If there is another reason for not running the breather pipe I'd like to here it. It's really just the chance of inhaling dust and dirt. Best of balance. Neo
October 27, 200916 yr The Cabestany replica I had only had the left hand side breather drilled and it used a breather pipe made out of plastic that melts, so it would melt shut when hot. I think this is the main reason why it is better to run without the breather or better still drill the right hand breather out and run two non-meltable breather pipes.If there is another reason for not running the breather pipe I'd like to here it. No, I think you have it correct unless something has changed, yet I was not sure if they were putting a tube on them at all, as at least on the US bikes I have see with Dellortos, the long hoses were totally removed several years ago. The biggest thing about single vent is not dirt and dust as Neo suggests, but mud and water as well. Dirt and dust may eventually find their way into the bowl, but mud and water can shut things down right now! Unlike a system that needs to flow at high rates, angles are not a problem. Even the factory ports are drilled at right angles. The bowl are simply needs to breath a bit, reliably, to accomodate fluxuations in level and vapor pressures, and is extremely sensitive due to the fact the entire operation is based upon pressure differential and the ability to "suck " fuel uphill from bowl to intake which requires a balance for proper regulation. As Tony suggests, a nice little 90 degree insert similar to the dellorto would be nice, yet the required thickness of the material may prohibit doing this out of ally, as the material thickness provided by the exhisting cast nipple does not allow for much expansion. However, some bit done in stainless with a wall thickness similar to the brass tube and on a taper fit would be just about right! Go for it Tony! Remember, the ones on the dellorto are pretty small ID, yet there are two, soI am totally unsure if only one would suffice.
October 27, 200916 yr Must be my birthday, carb & manifolds arrived today with spare JJF needle & #42,45 pilot jets & #122,125 main jets to fine tune jetting. The carb top has an right angled top with the instructions saying the standard dellorto cable guide screws in if needed, this should be of use to those guys who have one with the straight upward threaded adjuster Looking at the vent I'm thinking possibly a fish tank fitting that Ive seen used for routing hoses on enduro bikes may be able to fit over it, bit of checking to do there Hopefully will be able to kick the bike over by the weekend & give it a try, thats the downside with having a fresh engined 290
October 28, 200916 yr Quick play after work tonight, material is black acetyl which I had lying around Hole is 3mm like the vent & hose is located for 10mm, drilled 5mm until broken into vent diameter. Pushes onto original vent & can be turned to run hose where ever suits, shouldn't touch the muffler as its no wider than the float bowl I may remake it at a later date so that it locates further onto the vent Sorry for the lack of clarity, sent from phone to email which loses detail. Will see what happens if I use the usb cable Edited October 28, 200916 yr by tony27
October 29, 200916 yr Hmmm, need to come up with something like this for my keihin, breathers always touching the exhaust in standard form. What'd you guys reckon about blocking the one breather with epoxy, and running one tube from the exhaust side breather, to the rear of the bike, where it can split into two hoses using an aquariam style splitter? one going to by the shock, the other going to by the brake pedal? Looks neater with the fewer hoses on view, and still unlikely to block both hoses? Something like this http://www.overclock.co.uk/product/Danger-...tting_8016.html Edited October 29, 200916 yr by shercoman2k8
October 29, 200916 yr Copy that in ally now, so you don't melt it! That'll be the mark 2 version if it turns out the hose is needed. The hole for fitting over the vent will have to be either stepped or a electrode made with matching taper Jamie, if you look in the same section of that site you'll find the right angled fitting I was thinking of trying. Only thing is not knowing whether the sizes are outside diameter or the more common way of labelling hoses on inside diameter, most likely to be too big anyway. Your idea of split vent sounds worth a try & I've seen something similar before
October 29, 200916 yr That'll be the mark 2 version if it turns out the hose is needed. The hole for fitting over the vent will have to be either stepped or a electrode made with matching taperJamie, if you look in the same section of that site you'll find the right angled fitting I was thinking of trying. Only thing is not knowing whether the sizes are outside diameter or the more common way of labelling hoses on inside diameter, most likely to be too big anyway. Your idea of split vent sounds worth a try & I've seen something similar before Hmm, I saw that right angled elbow, it looks awfully small for a 6mm 1/4" inner diameter. I have a 90 degree elbow sitting here which is for a 6mm ID hose, the blokes down the automotive store gave me it with my last lot of hosing in the packet, which I just want to mention, they gave for free. Its originally a battery acid breather, but fits great in fuel hose or on the carby! Going to try out some of these on my keihin whilst the bikes in peices, see what I can come up with!
October 29, 200916 yr Can you work out if the fitting will push onto the vent, trim the extra off so the start of the bend is at the end of the vent & you'll have something very similar to what I made. Best thing with thin wall plastic is that generally it will stretch
October 29, 200916 yr Good news guys, I've just removed the adjuster from my dellorto & screwed it into the oko-same thread luckily. The original cable fits with maybe 1mm of extra freeplay Tomorrow on the way home from work I'll pick up some fuel line & a inline filter then have a go at kicking the beast over. Had a quick look at the jets fitted & so far would have to say they're larger than the settings for a keihin that I've got printed out here 128 main 48 pilot JJH needle 4 slide Will be interesting to see how far out these settings are
October 29, 200916 yr I will Can I ask what difference you noticed with the v-force reeds? I noticed the box in the background
October 30, 200916 yr That'll be the mark 2 version if it turns out the hose is needed. The hole for fitting over the vent will have to be either stepped or a electrode made with matching taperJamie, if you look in the same section of that site you'll find the right angled fitting I was thinking of trying. Only thing is not knowing whether the sizes are outside diameter or the more common way of labelling hoses on inside diameter, most likely to be too big anyway. Your idea of split vent sounds worth a try & I've seen something similar before You may want to take this time to do a bit of pre-fitment to the bike. On my '05 bike I had about 8mm clearance between the vent and the muff with the Kiehin, partly due to the way the carb was twisted in the flange to obtain clearance for the top of the carb against the fuel tank. My bowl is currently hard up against the rear br brake res preventing it from rotating more, and the top is hard against the fuel tank on the '07. It is a cram, yet I don't worry about the vents now. Other thoughts on an ally 90 angle, a common t-handle tapered hand reamer may work to get a proper interferance fit, specially if aided by a dab of sealer or epoxy. I would stay away from any long tubes(Jamie), I prefre no longer than the bowl. This(hopefully) allows minimal negative bowl pressure produced by any trapped fuel in the hose. It is an odd thing that happens, but a droplet in a hose can be similar to an air bubble in a way, and difficult to move! This works against the bowl pressure and can have very negative effects. Change the jets Tony! Try 42/ 115 and see what you get, needla in the 2'nd groove down. Edited October 30, 200916 yr by copemech
October 30, 200916 yr Jamie, I've run the vforce pretty much from new so can't tell you what the original reeds were like. Bearing this in mind my 290 is electric smooth with no steps in the delivery at all, 1 of my clubmates has just fitted 1 to his 08 rev3 which has a keihin fitted standard & he mentioned that its given more bottom end but can't comment on top end as he doesn't ride the big stuff. Only downside is having to cut the airguides off the manifold meaning if you take it out when you sell the bike that you should replace the manifold If you can find somewhere that sells them(have seen on ebay) they're worth trying if just for the trickness factor Cope, thought you'd say to drop the main jet size, will have a look on ebay tonight & order 1 of the 10packs to suit the 24mm as they seem to have the correct range The hose that came with the carb for the side vent is only about 100mm long with the 1 for the overflow being about 350mm long, won't be running them to start with & will only try once I'm happy with the jetting
October 31, 200916 yr I would stay away from any long tubes(Jamie), I prefre no longer than the bowl. This(hopefully) allows minimal negative bowl pressure produced by any trapped fuel in the hose.It is an odd thing that happens, but a droplet in a hose can be similar to an air bubble in a way, and difficult to move! This works against the bowl pressure and can have very negative effects. . I forgot all about negative pressures, that may explain my poor running on times. So one short hose, with a few holes along it? then wrap it in a fine mesh like the mudguard mesh to stop the **** blocking the inside of the pipe?
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