*CSC 250cc RX-3 Cyclone

Discussion in 'Thumpers' started by Chad05gsa, Sep 3, 2014.

  1. Desert Denizen

    Desert Denizen The least interesting man in the world

    Joined:
    Apr 24, 2016
    Oddometer:
    259
    Location:
    29 Palms, CA
    What gear were you in when hitting the rev limiter? I'm guessing not 6th, unless you were drafting a crazed 18 wheeler semi driver.
  2. Jay_In_Milpitas

    Jay_In_Milpitas Zero to sixty in February

    Joined:
    Feb 25, 2016
    Oddometer:
    576
    Location:
    Milpitas, CA
    Yes Denizen, sixth gear with stock sprockets. On my commute I was usually in the inside lane for the freeway portion, but that was only about six miles. Fully suited I only weighed about 155 lbs.
  3. Desert Denizen

    Desert Denizen The least interesting man in the world

    Joined:
    Apr 24, 2016
    Oddometer:
    259
    Location:
    29 Palms, CA
    I am very interested in the RX3 for use as a very long distance ADV/tourer, mostly on secondary roads. Sometimes, however, the Superslab is convenient for getting around some cities or avoiding long detours. So my question about RPM in 6th gear has me questioning the gearing setup. In my experience, if you are able to run to the redline or hit the rev limiter in top gear, one should be able to drop a tooth or two and calm things down a bit. It would seem that the engine has sufficient torque to pull a taller gear. I know Milpitas is flatter than a Chinese tortilla, so are you geared for the nearby mountains or just standard?
  4. pyoungbl

    pyoungbl Colonel Blood

    Joined:
    Apr 20, 2007
    Oddometer:
    1,593
    Location:
    Portsmouth, Virginia
  5. Jay_In_Milpitas

    Jay_In_Milpitas Zero to sixty in February

    Joined:
    Feb 25, 2016
    Oddometer:
    576
    Location:
    Milpitas, CA
    I'm still running the original 14/44 gearing.
    I feel that the transmission ratios should be changed by reducing first gear about 15-18 percent, reducing second gear about 8-10 percent. That would help the stock bike get going from a full stop better. The rest of the ratios seem fine. In addition to better initial acceleration, the engine would also more easily manage a higher over-all ratio when going on interstate sections. It could be geared tall enough for 6th to be a "loaf along" with the rider dropping to 5th for passing.
    I would also like to see a different retention method for the countershaft sprocket to more easily allow roadside changes.
    Desert Denizen and Huck369 like this.
  6. Desert Denizen

    Desert Denizen The least interesting man in the world

    Joined:
    Apr 24, 2016
    Oddometer:
    259
    Location:
    29 Palms, CA
    I have not read J. Berk's books but having read his blogs since the RX3's introduction, I have been impressed with the bike's performance per dollar. I have been to CSC's store a few times and have seen it in the flesh. Just waiting for a little more financial health. No Kindle, poor me. :( Have you received your RX4 yet? Looking forward to a Ride Report.
  7. darmst6829

    darmst6829 Been here awhile

    Joined:
    Jul 25, 2006
    Oddometer:
    538
    Location:
    Ocean Shores WA
    The suspension is what I would change. Been looking at some Fastace forks and shock.
    JagLite likes this.
  8. GlennR

    GlennR Chasin' my tail

    Joined:
    Nov 4, 2010
    Oddometer:
    3,735
    Location:
    Sugar Grove or Denver, NC
    I'm installing the 300cc piston kit in my Zongshen NC250 that is in my Pitster Pro LXR250f.

    Everything "was" going fine until trying to reinstall the camshaft. The timing chain doesn't seem to be mating with the lower sprocket, which means the chain is too tight to get the left camshaft bearing up into place. I assumed that the timing chain would automatically mesh with the lower sprocket when I slipped it up onto the upper sprocket on the camshaft, but that didn't happen...

    Does anybody here know what I'm dealing with & have any tips on getting it back together?

    (I've reached the conclusion that repeating the same things over and over isn't going to work. :hmmmmm)

    Thanks,
  9. Jay_In_Milpitas

    Jay_In_Milpitas Zero to sixty in February

    Joined:
    Feb 25, 2016
    Oddometer:
    576
    Location:
    Milpitas, CA
    Do you have the chain tensioner removed to allow for slack?
    JagLite and Huck369 like this.
  10. GlennR

    GlennR Chasin' my tail

    Joined:
    Nov 4, 2010
    Oddometer:
    3,735
    Location:
    Sugar Grove or Denver, NC
    Yes, it's removed and the head is fully torqued to 28 ft. lbs.

    I've had the camshaft in place with the chain on the sprocket, but can't lift the camshaft high enough to slip the bearing onto the end of the camshaft. It's like the chain needs to mesh with the lower sprocket, to give me another 1/4" to get the bearing on. I have held the chain with both hands & rotated it and wiggled it, figuring it just isn't on the sprocket, and it never feels like the chain is engaging the sprocket's teeth. I just can't understand why it's not going right where it should.

    Wish I had a micro-camera like the surgeons use.
  11. Jay_In_Milpitas

    Jay_In_Milpitas Zero to sixty in February

    Joined:
    Feb 25, 2016
    Oddometer:
    576
    Location:
    Milpitas, CA
    It sounds like the magneto components are in place. It that is true, removing the rotor and stator should let you see what is happening with the chain and crank sprocket. Also gives you opportunity to clean & inspect them.
  12. pyoungbl

    pyoungbl Colonel Blood

    Joined:
    Apr 20, 2007
    Oddometer:
    1,593
    Location:
    Portsmouth, Virginia
    GlennR, I had the exact same problem. I ended up loosening the chain a bit so it dropped down off the lower sprocket, then pulled the chain up in a slightly different mesh with that lower sprocket...somehow that gave me the extra microscopic bit of play so I could get the darn bearing back on the cam. To this day I do not know why that worked but it did.
    JagLite and Huck369 like this.
  13. GlennR

    GlennR Chasin' my tail

    Joined:
    Nov 4, 2010
    Oddometer:
    3,735
    Location:
    Sugar Grove or Denver, NC
    Thanks for the tips. I've made a little progress. I confirmed that the chain was off the lower sprocket and was able to work it back on using a wooden paint paddle.

    I got it both ends on TDC, but I'm still running into the problem of not having enough clearance to slide the bearing onto the camshaft. I've rotated the crank a few times but that didn't give me the clearance. There has to be "something" that I'm missing. Sure has me stumped.

    Maybe a drink or two will help.:jkam
    JagLite likes this.
  14. GlennR

    GlennR Chasin' my tail

    Joined:
    Nov 4, 2010
    Oddometer:
    3,735
    Location:
    Sugar Grove or Denver, NC
    After pulling the head I realized that I'd installed the plastic chain guide before confirming the chain was engaged with the lower sprocket. That fixed it clearance issue.

    But, I forgot to reinstall the head gasket...so, I get to try one more time. We're at the coast for a few days, eating & drinking. I'll fix it we we get home. I don't mind being forgetful, but I hate being clueless!
    JagLite, Navin, Huck369 and 2 others like this.
  15. Jay_In_Milpitas

    Jay_In_Milpitas Zero to sixty in February

    Joined:
    Feb 25, 2016
    Oddometer:
    576
    Location:
    Milpitas, CA
    Very good.
  16. Chadzu

    Chadzu Lost In Space

    Joined:
    Nov 7, 2017
    Oddometer:
    831
    Location:
    Utah
    Glen, did you use the 82mm kit or the 84mm kit?
  17. Chadzu

    Chadzu Lost In Space

    Joined:
    Nov 7, 2017
    Oddometer:
    831
    Location:
    Utah
    Question for all of the RX3 guys. Does the Delphi EFI that comes on your bikes have an IAC built in? In other words does the EFI have the ability to adjust and hold the idle speed?
    Navin likes this.
  18. GlennR

    GlennR Chasin' my tail

    Joined:
    Nov 4, 2010
    Oddometer:
    3,735
    Location:
    Sugar Grove or Denver, NC
    I'd didn't know there were two sizes available. I think mine says 82mm. I'll check when we get back home.
  19. pyoungbl

    pyoungbl Colonel Blood

    Joined:
    Apr 20, 2007
    Oddometer:
    1,593
    Location:
    Portsmouth, Virginia
    Yes, the EFI does that. In fact, other than messing with the throttle cable I cannot see any way to change the idle speed. Even if you were to take all slack out of the throtte cable the EFI would fight to keep the idle set.
    JagLite and Chadzu like this.
  20. ChopperCharles

    ChopperCharles Long timer

    Joined:
    Jun 7, 2006
    Oddometer:
    4,042
    Location:
    Durham, NC
    Yes, it's an active EFI system. SSR Buccaneer is the same way. The Hima has a much, much simpler system.


    Charles.