No announcement yet.

Juice Box Tuning

  • Time
  • Show
Clear All
new posts

  • Juice Box Tuning

    Brooks & Mike,

    Feel free to interject any info you have but I have a suggestion for you.

    Recently, a customer came in with a brand new superior motor on a sport-type ped. He said he installed a juice box on a new motor and it ran great for about 15 minutes then he couldn?t get it started again.

    It took me all of about 2 seconds to realize it had no compression.

    His G/F was standing there, and her hip dropped about 3 inches when she snapped at him "after all that money you just put into it, it needs MORE WORK?? she barked. I was feeling his pain.

    After taking the head off it was easily determined that a new piston & head kit were in order. He was very bummed. He told me that it was new. I had no reason to doubt him whatsoever. It looked new. Looked like it had NEVER been fired, until you looked at the cyl walls and the sides of the piston. The ring felt like a file.

    I told him it was typical oil starvation, from either a lean setting or improper mix. I asked his mix, he said 25:1. He was knowledgeable on oil and has other toys (jet skis). He left it, and came back 2 days later to pick it up (thanks Maggie for the speedy service) with new Superior parts installed. I told him I wasn?t going to start it. I had no idea if the fuel in the tank was correct.

    He brought back with him a gallon of fresh gas and we mixed it right there. He also had the installation sheet for the Juice box in his pocket. He pulled it out and handed it to me, what struck me (first time I read it) as odd was the sentence on the instructions, #3

    "Carburetor tuning may be required for maximum performance. In our testing a leaner setting was required. Ultimately, it is your responsibility for proper carb tuning."

    From our testing and operation, I have yet to see a motor tune lean with a juicebox. On all the Tanaka's, Mitsubishi's, Chitsubishi's and others we have put them on all needed to be tuned fatter (richer) than it was stock, or where it was before the juicebox. That in it self is no big deal, but what is the problem from your statement is you are suggesting the operator to lean it out to begin with. Some may not even try to start it first, but lean it and then start it.

    This fairly knowledgeable (not experienced) rider thought he was doing the 100% right thing and he baked a motor within minutes because he was way too lean.

    My suggestion, even if you are finding motors leaner after the juicebox is always tune the carb from too rich to correct. There is nothing technically wrong with your instruction sheet, so I'm not trying to be picky, just hopefully you can word it so it doesn?t suggest:

    "Hey dude, turn your adjustment screw in 1 full turn before you start it!"

    If someone asks me to tune his or her carb, I always open it up at least 1/4 turn first. That way I KNOW it is too rich. Then I start to tune it.

    That same formula would have saved this rookie pedder from another $100 bux, but more important than that his G/F wouldn?t have been the rabid ice weasel from hell in front of someone else. Poor guy...

  • #2
    Sounds good Jim. I will see what we can do about changing the instructions.