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Discussion Starter #1
I put my first big bore on the '07 case and i am having a new problem (for me) that I could use your wisdom/learned lessons...



So the motor has a V2 165 race head (ported) TK35S cam, and with a 165 cylinder & scut piston. The engine also has a Takegawa light weight flywheel and stator. To complement this it has a 28mm PK Keihin carb and a PC exhaust.



The bike starts in the first kick and idles like a champ, however the problem is that when I open the throttle and get the RPMs up, the engine starts pulsating. I do not think I am redlining the motor, but it seems that the engine is not getting enough fuel...



I live at 8500 feet, and bought the setup from a California.



Any ideas?



thx.

JC
 

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Check the basics? No water in the fuel bowl? That'll cause those symptoms. Cam and ignition timing, valve lash, vacuum leaks? Likely need to lean it out with the elevation change.
 

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Discussion Starter #4
Valve lash? is that the valves hitting the piston?



I leaned out the carb a bit, I changed the pilot from a 42 to a 40, and lowered the clip from middle to #4 position; the main jet was set at 105.



As for cam ignition and timing, I set the valves at TDC matching the cam (loose tappets); the TB stamp was to my left as I faced the CAm and installed the cam gear at TDC relatice to the piston and iginition. As for the carb, it was dry when I installed it and the fuel is fresh (no water). I'll try a fresh plug tomorrow and check the timing again.



Thanks for the tips;)
 

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To give a bit more detail on the symptoms, the pulsating occurs when I hold the throttle half open. The engine revs up like a champ but it peaks and bogs down, then it revs back up and bogs again, etc. This occurs with the throttle half open or fully open.
 
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