houseape1000 Posted August 8, 2012 Report Share Posted August 8, 2012 Well Iv'e done it......got rid of the scorpa and bought a 08 raga 280 with a 250 jug on it. I've stripped it down and re-greased it and I have to say despite others postings I think it's really well made. Are the keihins really finnicky ? The day after I bought it Istarted it and the carb was pi**ing fuel from the overflow at the base of the foat bowl. I altered the floats slightly ( so it presses the plunger on the valve about halfway in as the floats hit the top of the float chamber ) and now all seems well, although it wasn't leaking when I tried it before buying. I'm gonna be using castrol atf dexron 3 in the transmission and castrol power 1 racing 2t oil at 80:1 ........comments anyone ? The previous owner used carlube atf Q3, I would like to use the recommended oil but don't want to chance having two types of oil in there if theres a little bit left stuck to the clutch plates. Bike feels really good, gonna have a play tonight and take it to Cowm on Saturday 11th. The front suspension seems really stiff but I will have a good go before changing things. Andy Quote Link to comment Share on other sites More sharing options...
sting32 Posted August 8, 2012 Report Share Posted August 8, 2012 (edited) Take carb back out, when carb is upside down (and level at where the slide goes into the carb) Then, I believe the floats will be level horizontally when resting on its needle valve. But I am just trying to recall from memory, someone else might chime in with better information, measurements. I think level is a good start though. Dirt was probably (My guess) the reason it was overflowing? But the kehins are harder to get bowl off, and if you aren't careful, I dont know what all you can bend, Kehins can be finicky, I think, if you are... I adjust my idle mixture as conditions change through out my day (honestly about 2 times unless really big weather changes during competition)... But usually not more than 1/8th turn max, if you know what I mean from the last good adjustment... really depends on weather. the main jet can be trapping oil when gas has alcohol in it (least that is my experience) plus I suggest a filter on the hose that supply's the carb, as it is easier to change it than remove carb to clean out if you know what Im sayin there. I was under the understanding that most like the Delorto's better on smaller displacement engines, but I ONLY ride Raga 300's anymore, so what do I know, Edited August 8, 2012 by sting32 Quote Link to comment Share on other sites More sharing options...
michael martin Posted August 10, 2012 Report Share Posted August 10, 2012 Float level is very important with the Keihin so read up on doing it proper. Floats should be parallel to FB base when float tab just touch's the needle. Not depressing the needle just touching it. Stock jetting for 300 is 45 pilot, 122 Main, JJH needle in middle position, air screw out about 11/8 turn (if float level is right) but with 250 jug might be a little different. Still should be close. Quote Link to comment Share on other sites More sharing options...
sting32 Posted August 10, 2012 Report Share Posted August 10, 2012 Float level is very important with the Keihin so read up on doing it proper. Floats should be parallel to FB base when float tab just touch's the needle. Not depressing the needle just touching it. Stock jetting for 300 is 45 pilot, 122 Main, JJH needle in middle position, air screw out about 11/8 turn (if float level is right) but with 250 jug might be a little different. Still should be close. Good job Michael, with the 300 specs, but what should it be on the OP's bike, he says it is a 280, but that has the 250's cylinder and piston on it? Me? I say he needs a delorto, but that wont be what he wants to hear, lol. Quote Link to comment Share on other sites More sharing options...
laser1 Posted August 10, 2012 Report Share Posted August 10, 2012 I love the smooth yet crisp Keihin on the big bikes, but never got my old 250 dialed in with it. I preferred the low end responsiveness of the 26mm Dellorto, but didnt care for the classic PHBL lumpy idle. A correctly jetted VHST 26mm is the best of both worlds IMO. I agree with MM on the float height. The K's are finicky until you find that sweet spot - then all set. His jetting should be close for a 250 as well - maybe a 120 main, but will depend on the gas you use. Our 300's here like a bigger pilot - 48 seems to be the common size. (at sea-level) Your fluids should be fine - play with it as it will determine how the clutch engagement feels. Keep it clean! Try type F for a more abrupt engagement, gear oil for smoother. (can be draggy though) 400cc max. Quote Link to comment Share on other sites More sharing options...
houseape1000 Posted August 11, 2012 Author Report Share Posted August 11, 2012 Thanks all, Bike seems to run superb as is but I will reset floats to parallel soon. I haven't tried a gasser with a delorto but I really like the keihin so it's staying on. Although my old scorpa was better than me I now feel that it's been holding me back, the difference is amazing. It's easier to balance, hop, wheelie....hell it's just better by a country mile ! Andy Quote Link to comment Share on other sites More sharing options...
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