I recently trashed the top end on my 2000 KTM 300 EXC after a bit to long of a high speed run. Bottom line is - it felt like the classic top end going bad.
Some additional back ground. Just prior to this i had messed with "jetting" in that i had went to a #7 slide from a #6 to cure classic KTM 1/8 throttle richness. I had been advised this should not impact main jet needs etc as it would only affect the smaller throttle openings - so left all else as is (185 main, 42 pilot, 1466n needle, clip in middle, air screw 1 1/2 turns out, Maxima Super M oil at 40 to 1, 50/50 blend of pump 93 octane with 110 octane). Prior to this plug read fine anywhere above a 1/8 throttle sorta ride.
Upon tear down - one messed up cylinder already sent off to US Chrome for a replate, new piston etc on order. Plug - a nasty greyish whiteish color (clearly to lean!) But...when i spin the crank around i notice a very thick and stickly dark black oily goo on the crank halve - not a ton - bike needs to be leaning on side stand for what ever volume of this glop to be enough to lightly coat the crank.
My Qustion is - did i blow a seal on the right side? when i compare this to the tranyy oil - much thicker and darker in color. Is this simply partially combusted premix built up in the crank case from my failed starting attempts? Or....do i need a new seal? As cylider is off for replate cant do a leakdown test, and as a race is coming up cant really wait for its return then wait for new seal to arrive. Had i not noticed the oil on crank - i would never of thought of it as an issue - it was a simple top end issue - due to lean jetting or over agressive rigth wrist!
Another question - i believe i need to bump up the main a bit. but this size of main is way larger than anothers i have seen reported foe this bike at my elevation (500 to 1000 feet.) Now - this bike was bought used and supposedly jetted for Pennsylvania (bit higher elevation) I think the needel is not stock. Is it a a straight taper? If so i understanfd they require larger mains.
One more question - can i install a new seal with out spliting the case? I have the rigth side off, clutch basket off and can easily get to the seal now, and it is indeed normally installed from the outside of the case (just not with the crank in place)
Comments? Suggestions? (other than Ride Red, or join the cabbage patch etc!)
Some additional back ground. Just prior to this i had messed with "jetting" in that i had went to a #7 slide from a #6 to cure classic KTM 1/8 throttle richness. I had been advised this should not impact main jet needs etc as it would only affect the smaller throttle openings - so left all else as is (185 main, 42 pilot, 1466n needle, clip in middle, air screw 1 1/2 turns out, Maxima Super M oil at 40 to 1, 50/50 blend of pump 93 octane with 110 octane). Prior to this plug read fine anywhere above a 1/8 throttle sorta ride.
Upon tear down - one messed up cylinder already sent off to US Chrome for a replate, new piston etc on order. Plug - a nasty greyish whiteish color (clearly to lean!) But...when i spin the crank around i notice a very thick and stickly dark black oily goo on the crank halve - not a ton - bike needs to be leaning on side stand for what ever volume of this glop to be enough to lightly coat the crank.
My Qustion is - did i blow a seal on the right side? when i compare this to the tranyy oil - much thicker and darker in color. Is this simply partially combusted premix built up in the crank case from my failed starting attempts? Or....do i need a new seal? As cylider is off for replate cant do a leakdown test, and as a race is coming up cant really wait for its return then wait for new seal to arrive. Had i not noticed the oil on crank - i would never of thought of it as an issue - it was a simple top end issue - due to lean jetting or over agressive rigth wrist!
Another question - i believe i need to bump up the main a bit. but this size of main is way larger than anothers i have seen reported foe this bike at my elevation (500 to 1000 feet.) Now - this bike was bought used and supposedly jetted for Pennsylvania (bit higher elevation) I think the needel is not stock. Is it a a straight taper? If so i understanfd they require larger mains.
One more question - can i install a new seal with out spliting the case? I have the rigth side off, clutch basket off and can easily get to the seal now, and it is indeed normally installed from the outside of the case (just not with the crank in place)
Comments? Suggestions? (other than Ride Red, or join the cabbage patch etc!)
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