arnaud31

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About arnaud31

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  1. To all KTM riders and mechanics, I need your opinion on the service intervals of top and bottom ends of KTM. I have had this discussion with Dave before and he was quite reassuring but I could do with additional reassurance. I ride a 250 EXC 4T model 2005 with a 350 kit (the 450EXC barrel and piston). I rev it on a regular basis but not too stupidly though; and the engine has now reached 100 hours+ and as you know KTM says to service the bike after 90hours. So I am thinking that in the next 20-30 hours I should do something. I am quite happy to change camshaft bearings and timing chain (valves maybe) but I don't really want to touch the bottom end. The main bearings are the same as the 450 and 525 whereas the load is reduced (the KTM 350 kit probably output <35bhp and the torque must be 1/2 of that of a 525, so the load on the bearings is reduced. On the other hand the bike revs higher (I would say on average 3000rpm higher) since I can't grunt around in high gear. Using the formulea's used by bearing manufacturers to size bearings it would seem that a bearing subject to 1/2 load can rev 8 times faster (or longer) for same bearing life; i.e. in theory if the load on the 350 main bearings is 1/2 of that of a 525 and if the 350 revs twcie higher than the 525 (which is a worst case I think) then the 350 main bearings should lasty 4 times longer than that of the 525. Anyway enough about all that rubbish; the question is simple What is your view? Can I leave the bottom end alone as Dave suggests and if so how long for 200h, 300h... Thanks for you help, Cheers, Arnaud
  2. Could anyone out there explain me what would be the difference between 5W and 2.5W fork oil on an 2005 EXC racing bike? I currently have 5W in my fork but have bought some 2.5W and don't know whether I should save it for the winter (colder weather) or try it now. Thanks for your help, Cheers, Arnaud
  3. Could be the spring loaded seals (in the middle of the gasket carrier) that are damaged either when installed on the carrier or while slided on the WP shaft (you need to use a special tool, or make one, that cover the end of the shaft before sliding the carrier and you need to grease the inner seals to ease the installation). The seal's lips are very fragile, if damaged as soon as the engine warms up and the water pressure increases it starts leaking. Also, make sure that the spring loaded seals are installed the right way (spring outward on both oil and water side)! PS: you can also get a little bit of water with good seals when the bike overheat but it is then intermitent and minor; butu you problem doesn't seem to be intermitent. Arnaud
  4. Hi Dwight, You said in your post (some time ago): "But you will have to back off compression and increase rebound about 6 clicks or more. Be sure to set sag by the Golden Rule. Tear the pages out of the KTM manual pretaining to suspension sag into the garbage. The manual has been wrong for YEARS." Could you actually quote the number of clicks that need to be set-up (as a start) for front/rear compression/rebound. I ride a 2005 EXC and don't know if the manual is still wrong or has eventually been corrected!!! Thanks, Arnaud
  5. Thanks guys, My 250 EXC RFS (model 2005 with a KTM 350 kit) has 2200miles and 85hours. I will run it for another 50-70 hours and will have a look at the intake valves by then. I rev it high aswell (maybe not as high as Dave's son) so it should be a good indication of the longevity of 250's valves. Cheers, Arnaud
  6. Is this a problem also likely to happen on the 250EXC RFS intake valves? Or are these valves less at risk due to their smaller size and softer springs (I understand there is only one spring on the 250EXC, instead of 2 springs per valve on bigger bikes)? Cheers, Arnaud
  7. If your valve clerances are OK then it may be the automatic decrompressor (cam on the camshaft gear); this may therefore be normal. Your idle may be loo low, try to slightly increase idle.
  8. Hi, I have a reckluse clutch in its box and haven't had a chance to install it yet. How long did it take you? Is the grinding a painfull process or was it quick? Cheers, Arnaud
  9. Removing the radiator to adjust valve clearances is not mandatory but make access (hence your life) much easier; as you will see that there isn't much room for the pair of hands needed to hold the gauge and the spanner. You can get away with only removing the left radiator (on the ignition side), but if you want to use a torque wrench for the valve cover bolts, you nay want to remove both radiators (unless you have a tiny torque wrench). You may be tempted to only move the radiators (with their hoses attached and coolant still in) but you will be wasting your time; it takes only a few minutes to drain teh radiator and unbolt it. When you refill the radiator don't forget to purge the circuit adequtely and don't overfill the radiators. Also make sure you really are at the TDC; it sounds silly, but the TDC is extremely hard to find. What I personnaly do (but you may think that it is going too far) is to take the WP cover and WP impeller out, which allow me to find the TDC by alining the WP pin with the cylinder head casing split line; it also allow me to check the wear of the seal carrier asmine as a tendency to wear a bit. Hope that helps, Arnaud
  10. you may want to use this link instead, you even get an idea of the cost of parts: http://www.ktminfo.com/partscat/catalog.asp Cheers, Arnaud
  11. Hi, Dave seems right indeed. I have tried to install the seal carrier as suggested and it seems OK so far. I however remain convinced that my original problem (bent valves) has caused some damages to the cylinder head or camshaft. Anyway I have regained hope now and might not have to fit a 2000 seal carrier yet (but I think that next time open the engine I will fit the 2000 carrier though). I need to ride a bit longer to confirm everything the seal carrier holds on. I will start racing again in february and the last thing I need is to worry about the seal carrier!!!! Have you personnaly had a similar problem on your bike before by the way? Cheers, Arnaud
  12. Hi NYKTM, I use the KTM plastic part to protect the seals when I slide the carrier on the shaft. I didn't polish the shaft but I had a good look at it and there is no sign of any defect on the shaft that could have damaged the seals. In fact my problem is not so much a leak through the seals. As I tried to explain in my first post, the seal carrier is being pushed out of the cylinder head toward the WP impeller which in turn wear it out to the point where the outer o-ring closest to the WP is exposed causing water to leak out of the engine. At this point I also suspect the seal carrier to be sufficienlty far out to cause oil from the engin to leak past the other o-ring on cam side and oil also leak through the engine out ot the drain hole of the WP. Dave's suggestion is really good and I will try to implement it in the coming days, but I also fear that the mistake I made with my engine (see 1st post, bent exhaust valve) has damaged the cylinder head/cover, making the seal carrier problem even worst. Cheers,
  13. Thanks Dave, It is good to see that I am not the only one who's had a similar problem. You see, I started wondering whether my cylinder head cover had been elongated when the exhaust valves collided into the piston of my bike (but maybe it has an is aggravating the problem!). I will try your tip and let you know (I expect to ride again next weekend). Could you please confirm that in your case the gasket carrier was being completely worn out (i.e. in addition of turning the coolant black because of aluminum did it also leak oil and water through the drain plug? Speak soon, Arnaud
  14. Hi I am desperately in need of some help to fix a problem on my KTM that no dealer I have spoken to so far have ever heard of. Background information: I ride an 05 KTM 250 RFS that has a 350cc kit. When I fitted the big bore cylinder after 45 hours on my 250; I engaged the locating pin of the crank (to lock the engine in TDC position) in the wrong recess (it is only later that I found there was several recesses on my crank). When I re-assembled the engine, the timing chain was out by 2 links as a results of the piston not being quite in the TDC. I started the bike with the electric start, the bike did not fire but the electric start was powerful enough to get the engine turning and bent the 2 exhaust valves. Stupid of me you will say but this is a mistake I will not repeat. I got the valves changed, reassembled the engine and everything was OK. Problem: After approximately 5 hours, water and oil started pouring out of the drain hole situated at the bottom of the water pump case. Removing the water pump cover and impeller, I realized that the gasket carrier had been completely worn out by the water pump impeller to the point where the outer o-ring was exposed and leaking (aluminum part that have 2 seals on the inner bore and 2 o-rings on the outer bore and that isolate the oil from the water on the water pump side of the camshaft). I changed the gasket carrier thinking I had done it wrong and not fitted it correctly on the cylinder head. 5 hours later same problem. I removed the cylinder head cover, inspected the camshaft, made sure there wasn't too much sealing compounds, that the carrier was in the correct position, re-assembled the engine and I am back with the same problem. Has anybody had the same problem before. It would seem that the carrier is pushed out of the engine toward the impeller. But I can't work out how and by what. The engine breather is fine so the pressure inside the engine should be normal and the cylinder head must be clamping nominally on the carrier considering I put hardly no three bond this time. Please help me this is getting desperate.... Arnaud