Home Forums Shifter Karts New to Karts. Need guidance and advice

This topic contains 7 replies, has 3 voices, and was last updated by  Jim Derrig 3 months, 2 weeks ago.

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  • #66940

    Jose Abella
    Participant

    Hey there, as the title states Im new to karts. I picked up a kart from a friend and want to learn as much as I can. I know, its a CTS chassis, CR125 powered, and has brembo brakes. I got to try it out at a local track last week and I’m hooked. any info or help/suggestions would be greatly appreciated. Thanks in advance.

    #66942

    Jose Abella
    Participant

    some of the things I have questions about.

    Is that a good chassis?

    Typical gearing and final drive ratio

    What plastics can be used on that frame

    Something I noticed is I dont feel a drop in RPM’s on the upshifts. Bad clutch?, Shifting too late? gearing issue maybe? Seems to be running out of top end. It currently has a 24 rear, 15 front. 1.6 ratio. Thoughts?

    #66950

    Matt Martin
    Participant

    what track?  gearing depends on track.  loss of top end might be gearing, might be carb setup, might be engine maint.

    how many hours on the motor?

    if you’re just starting out, a straight, not-cracked chassis is all you need.

     

     

    #67005

    Jose Abella
    Participant

    Matt, track is Orlando Kart Center. Not sure how long the straights are but that was my initial impression. Unfortunately I don’t have a documented history on motor so I can only speculate. Seems to have tons of power when it comes on. I noticed that there is no “power valve”. From what I’ve read, it has something to do with not needing so much on the bottom end. Not sure.

    #67023

    Matt Martin
    Participant

    A slipping clutch will cause rise in RPM without a change in speed.

     

    I would ask around the folks at that track what gearing they are running, and what carb setups they’re running.  If things are still going awry after those adjustments, you should look into having the motor gone through.

    #67229

    Jim Derrig
    Participant

    Jose, except for starting from a stand-still, you don’t use the clutch at all.  All upshifts and downshifts are performed without using the clutch.

    My guess is that your clutch cable might be stuck or misadjusted, preventing the clutch from engaging fully.  Also, an upshift reduces torque so it is strange that the engine does not lower rpm’s on upshifts but the rpm’s are increasing for downshifts (I assume).  If the clutch was going to slip it should do it when the torque increases.

    Which leads to my next thought, which is that your upshifts are not upshifts at all.  Sometimes the shifter mechanism can become misadjusted or run into interference with a seat strut.  You pull back on the lever and it seems to move, but in fact there isn’t enough travel to move the tranny into a higher gear.  This used to happen to me on an older shifter (usually mid race, of course) when the engine mount would slip back a bit and the shift rod started hitting a seat strut and couldn’t move far enough anymore.   This only happens on upshifts because that moves the lever on the engine back toward the rear of the kart; there was plenty of room to pull if forward and downshift.

    • This reply was modified 3 months, 2 weeks ago by  Jim Derrig.
    #67233

    Jose Abella
    Participant

    Jim, first off thanks for the reply. Secondly, would it be possible that I’m only shifting into 3rd and THEN it doesnt upshift? just curious cause the first shifts are clear as day. I apologize for not making that clear in the first post but that is what i notice. BTW, today i took out the clutch to inspect and its as good as the new one i bought just in case. Definitely not the issue there. After I read your reply I realized that before I even drove the kart, I took off the shift lever completely because it was sloppy and had some play where it attaches by the steering. I fixed that but ow thinking about it, there is more than one hole to put the rod back to connect the linkage. That alone could very easily make a difference in how far the rod is actually moving. If the weather holds up, I will test your theory tomorrow. I’m anxious as it makes sense and I can relate it to what I’m experiencing. Thanks for the heads up. I’ll keep you posted.

     

    #67292

    Jim Derrig
    Participant

    It’s been awhile since I ran shifter, but IIRC the amount of travel required to upshift increases somewhat as you move up through the gears.  I recall that when I had my problem the first 3-4 gears always were available and the problem was with 5-6.

    Not surprising that the clutch itself is okay.  Honda clutches last forever in this application since you only use them for a start.

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