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Discussion Starter #1
As some of you may know, my bike is the F4 with 910 Brute engine hybrid. The following are my personal experiences with tuning it, so yours may vary.

Anyone who has ridden and old 16M F4, knows just how bad the mapping and heat issues can be. My take for this has been an aftermarket chip and second hand PC3 USB. Have gotten awesome results from this combo!

Starting from the beginning, i bought an second hand PC3 with a fault, but the fault was unstable TPS signal, and this is the problem with all PC3 models and is easily cured. The problem is rectified with cutting the black/white wire from the PC3 earth cable, and attaching it to the ground signal wire from the TPS (wire A). Also make sure you solder the joints, dont use the suplied connector, when the wires heat up, it gives erratic contact.

I had previously installed a chip that brought down the fan kick in temp to aproxx 95C, and now to get the idle right, i had to lean the trim pot to maximum lean position, and then the idle CO was 2,7 - 3,0 with fans running.

I then downloaded a map 727-502 from Dynojet database, and of we started. On the dyno the operator richened up the mixture right from the 1250rpm mark, right up to 7500 ish, the rest needed only minor detailing. Or so i thought...

On the road it was awesome, untill it really warmed up, i could feel it being very rich. So i put the 727-502 on it again and started the testing work. I leaned the 500 - 700rpm 7% to make it start properly. 1000 - 1500 i leaned 9% and now the idle returned. I generally had to bring the mapping down by 5 - 12% to make it proper. But i did find that adding 3 - 4% of fuel on 2% openings at 2500 - 5000 rpm takes the snatchines away completely, very smooth and electric like low rpm behaviour.

I took it back on the dyno, and the AF ratios had not really changed even though the conditions were the same, so im thinking that probe down the exhaust is not the way to do the dyno work. Other thing i found is that maximum power and drivability dont go hand in hand on this thing....

So you guys using the PC3 and having issues, plug it on the lap top, if the TPS signal dont stay put, do as i did and dont ditch the unit!!!
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