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About caflash1

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  1. caflash1

    2013 500EXC Engine Failure

    I was referred to this thread from ktmtalk.com. I have two 2013 500 exc's on my bench now with rod failures. 160 hours and 240 hours respectively. Both were noisy from new and always had stuff on the magnetic plug. The 2013 manual shows a roller bearing rod as standard. The fiche now shows a plain bearing replacement. Not superceeded just mysteriously a new design. My machine shop replaced another bad rod 500 crank same as my two recently. Seems the design is not a long term one with the tiny roller bearings in the rod. Careful as the wossner rod kit is another tiny roller bearing also. Only the oem kit is the new design. The failed rod pieces get thrown up on the cylinder and damage the cylinder and piston. Symptoms were noise and stuff on the screens. Took out all four ball mains also. Grumbly. Metal went through them. Not good. Both heads required both exhaust valve guides also. Cylinders were both extremely expanded at the top from compression pressures. Soft metal in the cylinder it seems. Recommended service is 105 hours in the manual. I hope you are subscribed the this thread so you will read this. Proactive replacement would have saved the cylinders from needing replating and new mains and the crank seals and new pistons
  2. I rejet every engine and typically they have 3-5% leakdown. I use cro moly steel liners in almost all my builds. You are correct on the fuel contamination from poor ring seal. Like I said the noise level, smoother shifting, more progressive clutch engagement was worth the money difference to me. Obviously not everyone budgets the same thing. Heavy clutch use, high heating of the engine, racing, all may require shorter changes. If you pull an oil sample at 20 hours and send it to a lab I doubt you would find hardly any reduction in its lubricating qualities. So the rest Is too keep the carbon in suspension. I use the t6 as break in oil. Versus Dino oil. Its viscosity is low enough to allow correct ring seal and its lubrication qualities are better for roller bearing engines. I use total seals quick seat instead of oil and a compressor and have less micro welding and quicker seating. I also use an equivalent stone grit size to the oem KTM cylinders for better ring life and less blowby.p I also use a one way case vent line valve to help lower the crank case pressure under the piston which increases ring seal and adds power. By all means changing oil every ride will not hurt a thing. On teardowns the Motul 300v motors show lower wear internally separate from the other things we notice. Like I said this only applies to the rfs engines. The later motors require the lighter thinner oils.
  3. So you have not tried Motul 300v 15-50 in a rfs engine? Or the factory recommended motorex 10-60? The comparison of the delo versus silkolene is interesting but not what I posted. My euro sidecar and Smr racing engine builder buddies only have the 300v in both shops and use around five hundred liters a year each. I am on my second hundred builds myself and as stated I ship all my motors with the t6 Instantly noticeable to drain the t6 out and refill with the 300v. If your judgement is financial only then do not use it. The idea that there is no advantage is simply not true. 3-400 miles on the 300v before the polymer chain shortening from the gear box lowers the viscosity enough to increase the motors noise level and the clutch becomes not as smooth in its engagement and the shifter requires more force to shift is what we have noticed. This only applies to the rfs 400-613 engines for sure. May or may not have similar results on the 530's and 500's
  4. Extend the change intervals to what I posted and the cost difference is negated. Bike shifts better, clutch is smoother, engine is quieter with the thicker more expensive oils.
  5. I build custom rfs engines since 2005. On my second hundred. Every motor leaves here with 1.25 liters of rotella t 6 5-40. Even longer life with the use of the motorex and Motul 300v. Stretch the changes. 8-900 miles if the motor is jetted correctly which very few are and the ring seal is good also.
  6. Good points about learning. Replacement motors are not around for an exc. seen one in the last two years. The 2005 is my favorite year rfs. Everything fixed. Suspension, frame, ignition. For the money invested the 300-500 hours of riding you will get is a real deal. $4 an hour roughly
  7. The idea of taking a racing engine apart to "see" what's in there is nice but meaningless. Then what? Sorry. I have done 100+ rfs engines and the odds of you either saving money or being able to rebuild this well enough to last are small. And I am standing at my bench with every part in stock to build your exact engine like new with oem parts I scrounged and reconditioned.
  8. I do these everyday and the fine dust goes through the filter and eats the ring and stock intake valves. Same question. Do you use no toil?
  9. caflash1

    KM EXC 450 wont run

    all Pre 06 stators internally short the ignition windings. Ohm the blue female connector coming out of the ignition cover. New was 15 ohms. At 13 its partially shorted. Next short the coil does not fire.
  10. caflash1

    2001 400 exc value?

    I have a grenaded 2001 on my bench. Made it a long time but the nut finally came loose. Part got past the lower non upgraded cam chain guide and jammed between the rod and the back of the crankcase damaging the rod and cracking the case. All fixable. Just a small application of cash. As Travis said. Fix it first. A few inner valve springs broke if revved hard. 03 had thicker wire in the springs.
  11. Do you use no toil air filter oil? And ride in dusty conditions?
  12. Unless you have no budget the amount of specialized parts and knowledge required to redo a 450 sx with its ti valves and bronze guides if stock are not something I would recommend doing as a first time complete engine rebuild. Odds are you might be able to do these but the details are the important part. The average guy would replace parts that are fine and not replace parts that are bad in my experience. You need to degrease the engine cases, crank and trans with gasoline several times to be actually able to feel the condition of the bearings. The oil film covers it up. I do these everyday and without a stock of good barely used parts this will be a very expensive stern chase. The guides must have been replaced long ago. Non lived long. Then the have the intakes recess into the head means the ti valves were cut which destroys them or the head is a stock exc type head not the ti parts at all. Normal is to replace the rod, replate the cylinder, new piston, and to check everything over by someone who has done these alot. I have every part in stock here to build multiples of your complete engine without your core. And the correct ti head fixed. Or will give advise and help as much as I can by remote control. Bob