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CThumper

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About CThumper

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    TT Newbie

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    USA
  1. CThumper

    CRF450R stock exhaust valves question

    Gotcha, I would think you need a stronger spring. In my opinion a heavier mass valve moving needs a stronger spring, but if you haven't had issues I guess it's OK. I found a full kit for $260, springs, valves and collars.
  2. CThumper

    2003 CRF450R Complete Rebuild

    Thanks! I'll add this to the list!
  3. CThumper

    CRF450R stock exhaust valves question

    Thanks for the replys all! Where did you buy them from? Or what type of kit did you buy? I'm having trouble finding a full kit; springs, valves, etc. I guess I can piece it together but would rather just outright buy it. I'm going to do all SS in the bike.
  4. I am replacing my valves on a 2003 CRF450R and I apologise if this is an obvious answer, I searched for the answer but couldn't find it. Are only the intakes titanium and the original exhaust valves are stainless?? I noticed a lot of the kits offered by like KW only include the intakes side. If they are SS on the exhaust side. Could I just do the kibblewhite or some other SS intake valve (and associated springs), and then buy just replacement OEM exhaust valves and springs? Or do I even need to find aftermarket exhaust valves that are SS? Thanks in advance!
  5. CThumper

    2003 CRF450R Complete Rebuild

    So I dug into the head today with a friend who's a auto mechanic. It looks like the heads are fine. The valve guides are really tight and the seats look great, I can clearly see the 3 defined faces/2 cuts. I know the valves have never been replaced and only shimmed once. I'm just going to clean up the head and use it. I'm going to go with SS valves/springs and lap them. Can someone answer this question, are the original exhaust valves stainless steel? Only the intakes are titanium? Thanks Ok I'll grab a new air filter, what would I apply the weatherstripping to?
  6. CThumper

    2003 CRF450R Complete Rebuild

    Is there another Vendor like Big Bore Thumpers that can build up an 08 Head for us?
  7. CThumper

    2003 CRF450R Complete Rebuild

    I attached a few pictures of the cylinder, the vertical marks don't feel like scratches, I can't feel anything with my fingernail. Maybe it its OK to skip the hone? I just want to do everything right while I have it broken down. I'm going to call MX Time tomorrow or Monday to see if they can do my head for me. they are ~$150 cheaper than Big Bore Thumper. Can I expect the same reliability out of my rebuilt head with SS Valves as Big Bore Thumpers? Thanks all! -Carl
  8. CThumper

    2003 CRF450R Complete Rebuild

    I figured if it's an OEM piston (2004) it would be a similar service life I could do the 2003 but i figured I'd like a bit more power. From what i've read some people say it makes more, some don't. I could go with the 2003 piston if it doesn't add that much power it might be cheaper. As far as the heads. So could I expect similar reliability say sending the head to MX Time and having them redo the head (cut Valve Seats, SS Valves)? that is $150 cheaper. I guess I could go with that route, maybe use that $$ on an exhaust. Is there an airbox fix that I could look into or just a better air filter? Thanks for the input!
  9. CThumper

    2003 CRF450R Complete Rebuild

    I wanted to add, I won't be racing this bike. I'd like to set it up for trail/sand dune riding with some calm (less than 15 min per trip) street time. I live near the beach in FL and thought this would be a fun bike to ride around the beach roads near me and hopping over to friends houses, no roads over 45 MPH. I think the sprocket & engine ice/high pressure cap will help. Is there anything else you'd recommend?
  10. I finally got some time to tear into the motor of my bike, a bit of history I bought the bike cheap after it was dropped in water running. The previous owner never was able to get the bike started again. I broke the motor down and inspected everything. Here's what I am thinking of doing, i'd appreciate any input or guidance on something that I might be overlooking. - Complete bearing replacement, Crank bearings look fine, some on the transmission side are a bit rough, but since it's split I will replace all of them. - Current Crank is within serviceable limits, no play up/down. slight side to side, within limits. I do not know hours but the internals aren't beat up so i'm figuring it's not super high hours. - Cylinder hone & inspection by machine shop. - Clutch looks fine. -2004 OEM Piston Kit, slightly higher compression than 2003. -2008 Big Bore Thumper Complete Head - Head is pretty nasty, its worth it to me to spend a bit more $$ and have the better heads that will last longer. - 1 new shift fork, the 4L Shift fork was bent pretty bad, all gearing was OK. - Manual Cam Chain Tensioner. -14 Tooth Front Sprocket - This bike is street legal, i'm not doing anything over 55 mph. - Engine Ice with higher pressure Cap. So am I missing anything? Do I have the correct years for Piston & Heads? Thanks in Advance!
  11. CThumper

    2003 450R hydrolock

    Thanks, I thought I had read the intake valves were prone to failure on 2003 and prior, if they are all interchangeable what makes the 2004+ better? Or am I wrong??
  12. CThumper

    2003 450R hydrolock

    Hey everyone first post, getting a really good deal on a 03 450R. It's street legal but has some issues, last time it was ridden it was dropped into a stream. He said it may have been hydrolocked, and hasn't been able to be started since. I've done some research but is there a good process to troubleshoot the engine or where would you start if your not 100% sure of the history?? I'd like to take the time and do it right. Also after doing some research it looks like this year had was prone to some valve issues, is it possible to update the head to a newer configuration? Or just better to stick with the current setup. Thank you all in advance, can't wait to get out on it.
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