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NaCltK9

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About NaCltK9

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    North Carolina

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  1. NaCltK9

    GPX nc250 crate motor

    Thanks again Chad!
  2. NaCltK9

    Heavy valve chatter when under load

    Sounds like I'll be pulling the engine out and inspecting the cylinder, piston, rings, bearings, etc... I'll also be checking the timing advance and the actual advancer for wear as Chuck noted above. Would a worn advancer be causing the detonation? I did a compression test for S&Gs and found mine to be 130-135 on a warm engine. It held that pressure for quite some time and i have 6-7mm of free play at the decomp.
  3. NaCltK9

    GPX nc250 crate motor

    Sweet! Looking for rear mount to front mount distance (center of hole to center of hole), front and rear mount width, bottom mount width, and if possible the distance from bottom mount to top of cylinder head. How'd you get a hold of the cases? That would seriously come in handy for mock ups!
  4. NaCltK9

    GPX nc250 crate motor

    Thanks Chad. Since you have an fse250r would it be too much to ask you for some measurements?
  5. NaCltK9

    Heavy valve chatter when under load

    XRs Only header with FMF Powercore 4.
  6. NaCltK9

    Heavy valve chatter when under load

    My bike has a crf front fender but is cut down in the rear for air flow to the heads and cylinder. I checked the plug and it looks damn near optimal as far as color goes. I've ridden this thing in tight single track in the middle of NC summers with only a little chatter which I knew was due to heat. Temp was in the 70s recently and it was doing this. Did i mention I'm running stock jetting (38 main, 110 pilot, needle in 3rd position) and a/f screw 1-1/4 to 1-1/2 out?
  7. NaCltK9

    GPX nc250 crate motor

    Wondering if anyone has actually purchased and fit an nc250 motor into an existing frame. The reason I'm inquiring is because i have a 2007 CRF250R roller in need of an engine. The nc250 with e-start and EFI is looking like it'll fit the bill. The engine schematic diagram with all the measurements looks like its about an inch too long from swingarm mount to front mount to use the stock mounting tabs though.
  8. NaCltK9

    Heavy valve chatter when under load

    Cam chain, tensioner and adjuster are fine and the chain, tensioner and guide were placed during top end rebuild. The adjuster actually works! One thing i didn't check was the plug for lean condition since i had put a new one in before the Enola ride. The older one had a nice dark brown color to it and no carb adjustments were made so I didn't even bother to check this latest one. I've always run a standard NGK DR8ES-L.
  9. Love the build. What rear brake pedal is that? It's a sexy piece
  10. NaCltK9

    Heavy valve chatter when under load

    I've tried using a timing light before and it gets to be a messy job. I like the static method. I'm wondering if heavier valve springs would help my situation. Something like Kibblewhite.
  11. NaCltK9

    Heavy valve chatter when under load

    The comp is 10:1 and the timing marks are all lined up at the "F" as described in the manual. I'm not sure what the advance or retard is at that adjustment point. In the tight, flowing ST it was fine and only chattered slightly even when wringing it out in 3rd coming out of a corner. It only did it up the hill climbs but it was real bad. As far as "pinging" is concerned, it was more than that. So bad that a guy following about 10 yards behind me on a KDX200 heard it and thought I was going to blow it up. I've run 93 pump premium with no issues until these past couple rides.
  12. Got a chance to ride the Enola Mid-East Hare Scramble course a few days before the actual race on my "87" XR200R and she was running great. After the first lap the hills I climbed in 3rd and 2nd gear turned into 2nd and 1st gear hills due to loss of power and I could hear the valves chattering so loud it sounded like a poorly maintained diesel Rabbit. After I got home I checked the timing, valve clearance and changed the oil and found nothing out of the ordinary. The next week I ran the Lost valley NCHSA course and there were some long hill climbs and I could hear the valves again. Same result and called it a day after 2nd lap. Never had this issue before. What is causing this and what am I missing? The engine is a stock 1999 and top end was rebuilt about 50hrs ago with Wiseco forged piston (65.5), Pro-X steel valves, new OEM valve springs, seals, retainers, etc...
  13. NaCltK9

    Up grades

    Any KTM full size foot pegs from 2000s on fit. Just need to grind a little bit in order to fit inside the OEM XR bracket. If you have big feet like me a shifter from a crf230f works and you get a little more options. FMF Powercore with an XRs Only header for cheap "performance" mods. Do something with the suspension and it'll go anywhere and stay bullet proof.
  14. NaCltK9

    Are these cheap cylinder heads any good?

    I've got an older Powroll engine with the stroked crank/rod and the 70mm bore for 245cc. I melted the Piston years back from detonation not using full 104+ octane race gas. This older build uses a rod with a 16mm piston wrist pin instead of the normal 15mm Honda. Started a thread on it a while back since Powroll was/is no longer around to get a piston from and needed some expert TT advice. Eventually used an 80s Yamaha yfm/ytm 225 piston and had it machined and skirted to work. It was a killer engine with great bottom and mid power. As far as reliability goes it served the previous owner well for over a decade with no issues. Had I not been a cheap ass and used full race gas (Sunoco 110 was available near me for $90 per 5gal can) I'm sure it would've proved reliable with regular maintenance.
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