dirtydownunder Posted March 2, 2010 Report Share Posted March 2, 2010 (edited) ok ok. my bike has a splutter at 4500 -5500rpm, before and after that spot is awesome. ive gone from 158 mains to 150 (and all needle clip positions) and 55 pilots to 45. at the moment im on 155main and 45 pilots (1 1/2 turns out on screws) with needle in middle position. (which is the best its been but still this splutter) the bike is. T5's, OKO 30's with pods (155, 45 1 1/2 turns out and n80f needles. 20cc domes (141psi on both) vf3's white knuckle intake stock stroke 64.75 wiseco's HJR dune/play port match ported cases-barrels 60/40 pump/avgas dynafs dyna coil so i tested everything i have, pickup gap leads with plug caps on gapped plugs to .6mm coil and stator resistance carb sync compression i tried the stock cdi and coil. check the vf3's (i couldnt see anything wrong) everything tested OK doesnt matter what i do it has this splutter and i have never ridden through it (i dont like holding it at this point) and the problem is only at high gear low speed, like if i shift into 6th or 5th going slow and holding the throttle pinned and letting it rev through the rev range, then it gets to this point and it splutters. If i have the paddles on its even worse. If i clutch it or drop it down a gear its awesome and if i go through the gears 1,2,3,4,5,6 its awesome, if ive got the razr2's (on sand/dirt) on ,you wouldnt even know it has a prob unless your in a high gear going slow and hit some boggy sand and hit WOT so i clutch it and shits wicked. its always felt like igntion but im not shaw with 2-strokes. Some peeps dont like these carbs and say to try the stockers but the throttle is wide open and it only splutters at this point everytime. ive had it on a dyno with no help. I might even try the stock jugs just because im running out of things to try. cheers for any help. Edited March 2, 2010 by dirtydownunder Quote Link to comment Share on other sites More sharing options...
fastbanshee8 Posted March 2, 2010 Report Share Posted March 2, 2010 How long does the sputter last, and does it feel like it's losing all power? To me, it's kinda sounding like it's lean on the needle. Don't mess with a bunch of carb changes at once, or you'll really never figure it out. While you have the carbs adjusted where they are now, try dropping the clips on the needles one notch, and see what happens. Are the carbs synched, and are you sure you don't have any air leaks? Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted March 2, 2010 Author Report Share Posted March 2, 2010 yup tried needle positions with current jetting and it didnt help, i dont know how long it lasts because i dont want to keep on it. and it looses power because it sticks on that splutter and i back off or drop down a few gears. i havent done a leakage test so i dont definetly know it hasnt got an air leak. (i doubt it does, ill see if anyone has a tester just to rule it out) thanx. Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted March 3, 2010 Author Report Share Posted March 3, 2010 TTmfT Quote Link to comment Share on other sites More sharing options...
_Hex* Posted March 3, 2010 Report Share Posted March 3, 2010 try a different coil like an oem one, the one under the tank had a similar problem. had a problem once with non resistor plugs when using dynatek also Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted March 3, 2010 Author Report Share Posted March 3, 2010 I originally had the stock coil so i tried the dyna because the stock one was giving funny readings, the dyna didnt change anything. im running br8es anyway. thanx man. Quote Link to comment Share on other sites More sharing options...
T_Shee Posted March 3, 2010 Report Share Posted March 3, 2010 if your gonna try any other parts i would start with stator. i hate to recommend throwing parts at it to try to fix it but ive seen stators cause some strange problems on these things and they are hard to diagnose. maybe if you know someone that can loan you one or something like that just to test with. good luck Quote Link to comment Share on other sites More sharing options...
harbinger of death Posted March 3, 2010 Report Share Posted March 3, 2010 yup tried needle positions with current jetting and it didnt help, i dont know how long it lasts because i dont want to keep on it. and it looses power because it sticks on that splutter and i back off or drop down a few gears. i havent done a leakage test so i dont definetly know it hasnt got an air leak. (i doubt it does, ill see if anyone has a tester just to rule it out) thanx. When I got my 03 with toomey t-6's on it the instruction manual for the pipes said some b.s. about an inherent sputter in the midrange due to the harmonics of the incoming charge or something retarded like that. I looked for the manual for exact wording but can't find it. I think it's just because they couldn't get the taper right on the needles that they send with the pipes. I never messed with it too much other than moving the clip position, which didn't really help. If I find my manual I'll get an exact quote for you. Quote Link to comment Share on other sites More sharing options...
drap660 Posted March 3, 2010 Report Share Posted March 3, 2010 I would say to try diff needles. just a slight taper or bend can cause this. 2nd thing would be to try stock carbs. I dont understand why so many people run aftermarket carbs on stock stroke/stock bore motors. Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted March 3, 2010 Author Report Share Posted March 3, 2010 if your gonna try any other parts i would start with stator. i hate to recommend throwing parts at it to try to fix it but ive seen stators cause some strange problems on these things and they are hard to diagnose. maybe if you know someone that can loan you one or something like that just to test with. good luck thanx t_shee, yeh the stator had crossed my mind just as a possible weird prob, ill see if i can borrow some ones. When I got my 03 with toomey t-6's on it the instruction manual for the pipes said some b.s. about an inherent sputter in the midrange due to the harmonics of the incoming charge or something retarded like that. I looked for the manual for exact wording but can't find it. I think it's just because they couldn't get the taper right on the needles that they send with the pipes. I never messed with it too much other than moving the clip position, which didn't really help. If I find my manual I'll get an exact quote for you. cheers HOD. I would say to try diff needles. just a slight taper or bend can cause this. 2nd thing would be to try stock carbs. I dont understand why so many people run aftermarket carbs on stock stroke/stock bore motors. but its only W.O.T, if it were a needle problem wouldnt just raising and lowering the needle help in some way ? yeh, stock carbs are next on the to do list. thanx. Quote Link to comment Share on other sites More sharing options...
flyhighprerunner Posted March 4, 2010 Report Share Posted March 4, 2010 Im honestly thinking plug caps. Maybe I missed the part where you said you replaced plugs and plug wire caps, but to me thats what it sounds like. Just the fact that it keeps going after that RPM.. But before you throw parts at it throw these, and they are cheap. Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted March 4, 2010 Author Report Share Posted March 4, 2010 thanx flyhighprerunner, i only tested them and they tested OK, the dyna coil comes with leads so im still using the orig caps. yeh it does feel like its blowing out the spark. The caps i ordered are at the store, i have to wait for the weekend so i can pick them up. $6 each woohoo Quote Link to comment Share on other sites More sharing options...
volcrano Posted March 4, 2010 Report Share Posted March 4, 2010 thanx flyhighprerunner, i only tested them and they tested OK, the dyna coil comes with leads so im still using the orig caps. yeh it does feel like its blowing out the spark. The caps i ordered are at the store, i have to wait for the weekend so i can pick them up. $6 each woohoo alll my buddies that run aftermarket coils have sputtering problems,i dont know whats up with those things.u try closing the gap on your plugs in case it is blowing the spark out?whats ur timing at?u dont really need to be running the 1/2 av gas either,thats really for 150+ psi.the av gas doesnt have anything to do with ur problem but u could save a lil money.did u change anything recently??my cpi pipes did that shit bout the same spot.i had to sell em. Quote Link to comment Share on other sites More sharing options...
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