Plug color feedback

Discussion in 'Motorized Bicycle General Discussion' started by fischer550, Jun 24, 2014.

  1. fischer550

    fischer550 Member

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    I took a 4 mile ride through all range of rpm's, no top speed plug chop for 20 seconds but I took the plug off and heres what it reads. Still is 4 stroking at bottom end, top end is OK but top speed is only about 26mph (with a 44 tooth, and still in break in) but I expect more from it when broken in hopefully? This motor is not stock. Tell me what you think. Running opti-2 at 100:1

    Plug is black, not wet black though but has a pretty dark color
     

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  2. Davezilla

    Davezilla New Member

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    plug looks ok for now... Top speed is about right for the 44 tooth, it'll get a little better as it breaks in some more.
    if the top end feels ok for now then keep whatever jet you're running in there, for the low end four stroking, you can either leave it be or move your needle down a notch by raising the clip up a notch and see if it goes away.

    he plug should be ok but you could try one step hotter on the plug and take a new reading, you're making progress.
     
  3. TwistedAlloy68

    TwistedAlloy68 New Member

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    I would run 50:1 or 40:1, 100:1 though doable just is not what these motors are made for. The tolerances and materials like more lube than 100:1. The highest speed I've seen with a 44 was 38 mph. Do a little piston trimming and open up the transfer ports and 35 is totally feasible. 38 mph was on a stock bottom end with some dremmel mods. What is considered not stock?
     
  4. Davezilla

    Davezilla New Member

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    There are several of us running Opti2 at 100:1 in here and have been running that mix for years with no issues... We got past that part already.

    As for the reason his bike is slow right now it's because it's a brand new engine and not even close to broken in yet... His bike will go fast after he gets some more seat time on it for sure with the mods he has. I can't tell all, but I know he has a Fred head and a ported jug, and possibly a pipe and a cut piston so it's just a matter of breaking in the engine and more fine tuning then it'll be fast.
     
  5. fischer550

    fischer550 Member

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    Thanks Davezilla, I've actually already got the clip at the leanest position, still 4 strokes from 0-half throttle but it's tolerable, at least for break in. So now I have the clip at the leanest position, and I have a size 64 jet in it. Most people said to stay with the stock NT jet (size 70) until it was broken in, but riding it like that was not tolerable for me. So with this black plug color, should I down jet a bit more or just leave it as is until 200 miles? (currently has 20 miles on motor) Will running it rich like this not allow the rings to seat?
     
  6. Davezilla

    Davezilla New Member

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    I'd say if it's tolerable let it break in and see if the 4 stroking on the bottom end goes away as the engine frees it's self up... Right now the engine has to push harder against the friction of the cylinder as well as the excessive blow by before the rings seat, this will improve as you ride it more and may end up right where you want it after a few more hours of run time. The other thing is 4 miles is probably about where the engine is just beginning to warm up to operating temperature, try to run it about twice that distance next ride, keep it close to home, but do the same ride twice if you need to and see how it goes.
    As long as it's all tolerable I'd leave it alone and put some miles on it.
     
  7. fischer550

    fischer550 Member

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    Will a hotter plug make a difference in performance? Or just plug reading?
     

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