Inner Rotor Kit Install and Timing

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New Member
Mar 4, 2012
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Oak Ridge NJ
First of all I would like to say hello, as I am new to this forum. I have been riding full size dirt bikes and street bike for a few years now, and am just getting into pit bikes.

I have been searching the web and specifically this forum for about five days now and I appologize if this issues was discussed (if so just post the link). Unfortunately I could not find the answers I am looking for. I have however determined that there is a great group of guys on this forum and quite possibly some of the funniest people I have never met (love the Flux Capacitor post I stumbled on)

Anyway I purchased an XR70 from a guy that was "trying" to make something sweet, for a really low price (my new project). he installed a Lifan 125 and along with the crappy ebay IRK. I am fully aware of the downfalls of the IRK on this bike so I am hoping to keep this thread from turning into a debate. The bike also has a Sheng Wey Carb on it (from my engineering and machining background it looks like garbage). I am fully planing on doing a 140cc engine swap and using a Mikuni as that is the carb I am used to. Unfortunately I will not have the full funds for the purchase for another month or so, and do not want that to hinder my fun in the meantime. I have played with the carb adjustments and needle hieght settings along with the different plugs in order to get the bike into an okay riding format (runs and idles with decent plug cuts) it still back fires a tad an is flat in spots. I am new to this IRK and am trying to figure out if anyone has any ideas on how to actually set/check the timing on this IRK (trying to rule out timing as an issue). I am used to a flywheel with timing marks, using a light or degree wheel off TDC. My experience in timing proves useless with this IRK. Any help will be appreciated.

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