betarick Posted February 25, 2013 Report Share Posted February 25, 2013 Hi all as anyone messed with carb jetting on a 290 evo? what size jets do you recomend and needle clip position & air screw setting? I remember changing jets on my old rev3 mukuni carb and made a big difference! Quote Link to comment Share on other sites More sharing options...
deadwood Posted February 25, 2013 Report Share Posted February 25, 2013 Hi all as anyone messed with carb jetting on a 290 evo? what size jets do you recomend and needle clip position & air screw setting? I remember changing jets on my old rev3 mukuni carb and made a big difference! Hi betarick is there something wrong with the way youre bike carburates at he moment? or do you just want to see what its like with different jets ? try 45 0r 48 pilot. 125 or 122 main . needle in 2nd clip from bottom as starting point airscrew in between 1 to 2 turns out try different settings see what feels best for you... Quote Link to comment Share on other sites More sharing options...
betarick Posted February 25, 2013 Author Report Share Posted February 25, 2013 (edited) name='deadwood' timestamp='1361831164' post='325556']Hi betarick is there something wrong with the way youre bike carburates at he moment? or do you just want to see what its like with different jets ? try 45 0r 48 pilot. 125 or 122 main . needle in 2nd clip from bottom as starting point airscrew in between 1 to 2 turns out try different settings see what feels best for you...[/s] Hi just curious about jet sizes and settings really! never really touched carb other than remove and clean. But just lately it seems to be using more fuel! At trials i seem to be having to refuel a lot! Edited February 25, 2013 by betarick Quote Link to comment Share on other sites More sharing options...
outlaw dave Posted February 26, 2013 Report Share Posted February 26, 2013 Check the float level as per John Lampkin's instructions. Quote Link to comment Share on other sites More sharing options...
betarick Posted February 26, 2013 Author Report Share Posted February 26, 2013 Check the float level as per John Lampkin's instructions. Float level is set as per johns instructions and as been rechecked! Quote Link to comment Share on other sites More sharing options...
steve fracy Posted February 27, 2013 Report Share Posted February 27, 2013 Never had to re-jet any Evo we have had! Other than a tweak of the air screw now and then with temp change, they run perfect out of the box at sea level. The 2013 is the very first one we have had to change the needle setting. Quote Link to comment Share on other sites More sharing options...
betarick Posted February 27, 2013 Author Report Share Posted February 27, 2013 Never had to re-jet any Evo we have had! Other than a tweak of the air screw now and then with temp change, they run perfect out of the box at sea level. The 2013 is the very first one we have had to change the needle setting. Bike runs fine! at a trial on sunday i had to fill up 2 times my brother who as the same bike managed to get round on a tank full! Quote Link to comment Share on other sites More sharing options...
deadwood Posted February 28, 2013 Report Share Posted February 28, 2013 Bike runs fine! at a trial on sunday i had to fill up 2 times my brother who as the same bike managed to get round on a tank full! if you had to fill up twice to youre brother getting round for a tankfull ? sounds like youre losing fuel somewhere. there was a few sections on sunday where the bike was at a severe angle, either up or down, have got the breather pipes routed correctly? Idid the same trial and got round for a tankfull,had to go on reserve for the last half dozen sections or so,, jetting in my BETA i s standard 125 main 48 pilot . ... Quote Link to comment Share on other sites More sharing options...
0007 Posted February 28, 2013 Report Share Posted February 28, 2013 Interesting comment and you need to pay attention to it 1) A motor could not consume double or triple the amount of fuel without fouling the plug and giving very obvious running condition symptoms 2) you could not rejet to make the engine consume half or one third the fuel 3) your riding partner has the same bike and rides it in the same conditions and consumes less fuel These things add up to a faulty component and NOT a change in adjustable parts My guess would be that are running fuel out the overflow while riding, try and duplicate the problem, put the bike on a stand and run it up in third or fourth gear to get vibration started, that way you can watch for fuel from the overflow (Adjusting float level does not compensate for a leaking needle by the way) I suggest you replace the needle and either replace the seat or clean it with a Q tip and blob of toothpaste as a cleaning / polishing agent Whatever you do don't change the settings, that would be fixing something that is not broken to compensate for something that is Best of luck and keep us informed Quote Link to comment Share on other sites More sharing options...
betarick Posted March 1, 2013 Author Report Share Posted March 1, 2013 Right had mess with bike today had carb in bits cleaned, needle on 2nd notch from bottomn air screw 1&half turns out new ngk irradium plug new air filter! ran bike up on stand and cant see any fuel leaking from carb overflow pipes even had front and rear wheels in the air still no fuel from carb overflow pipes! One thing i did notice was a hell of a lot of smoke from exhaust when cold! i mix my fuel at 70/1 and have never noticed the smoke from cold before today! do i have a crank seal problem? exhaust was cleaned and repacked not long ago? Quote Link to comment Share on other sites More sharing options...
0007 Posted March 2, 2013 Report Share Posted March 2, 2013 I would stick with the game plan, if you had a crank seal leak it would have no effect on fuel consumption A bad leak would make the bike hard to start, consume trans oil and the bike may run lean as you lose primary compression A lot of what comes out of your silencer (particularly when cold) is water vapor, it's easy to mistake it for smoke Why an Irridium plug?, I can tell you from experience that not every ignition system likes those plugs If a bike comes stock with it, it's because the system was designed around it (hence "system") It won't improve a bike Is it possible that your choke plunger is not closing completely because of debris? If your bike is using double to triple the fuel as your buddies then the exhaust will have a lot of unburned hydrocarbons in it that will burn off when the exhaust comes up to high temp like on a long hill climb Quote Link to comment Share on other sites More sharing options...
nelly1 Posted March 2, 2013 Report Share Posted March 2, 2013 do you ride it a lot harder than most ? Quote Link to comment Share on other sites More sharing options...
copemech Posted March 3, 2013 Report Share Posted March 3, 2013 Right then, I shall give you Beta lads a wee something to thing about on your Kiehin equiped Evos. On your conventional Kiehin PWK 28 carb, there is a tube that extends up into the bowl betwen the floats called an overflow tube. It is directly connected to an outlet which exits the left bottom of the float bowl. This tube is designed to provide an outlet for fuel in the case of a stuck float to prevent filling the motor with fuel, specially when parked. This "feature" will also promptly allow the bike to pee like a pup every time the bike hits a bump and fuel gets sloshed in the bowl, allowing a bit overboard, and out the exit pipe to vent. Thus wasted. Long story made short, BLOCK IT OFF! If your float sticks, your bike will flood just like any other bike has for generations, yet the chances are slim for a properly working bike. The actual tube itself makes the carb into a Chinezzse puzzle when attempting to install the bowl. I toss that as well and drive a sealing bearing into the hole! ps- your specific float level setting will aggrivate this condition, the higher level the more spillage, yet not eliminate it. Ta, MC Quote Link to comment Share on other sites More sharing options...
betarick Posted March 3, 2013 Author Report Share Posted March 3, 2013 Right rode a trial today and bike seemed to not want to idle right and had to mess with idle screw a lot also i have noticed that when i leave it ildling then blip throttle it sort of hesitates/splutters off idle! Did not notice any fuel leaking and only had to fill up once today same as our lad! Spoke to a few beta evo 2011 owners and they all say you need to do your main bearings as they have all done theres as my engine does not run smooth and is slightly noisey! Quote Link to comment Share on other sites More sharing options...
betarick Posted March 16, 2013 Author Report Share Posted March 16, 2013 Well removed and stripped my engine this week to find main bearings gone! sheild had dropped off stator side bearing also damage to crank seal! Had the bike running today and it seems totaly different revs crisp more compression harder to kick over and idles spot on! There where 3 cyl base gasket which have now been replaced with 1 that beta uk said i needed! Quote Link to comment Share on other sites More sharing options...
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