Before and after sync

binx

Registered
I just synced tb's and fuel mileage dropped. Heres a little history till now. 2005 busa with 9000k full synth,rs3 full exhaust and pcv. The bike had a little dip in cruising speeds 2800-3500 so I had it dynoed last year. It ran a little bit better but was still there. I changed the plugs and it also helped, but still noticable. Above 4k it goes fine but since Im in town alot it was driving me nuts. So this year I synced the tb's they were like 4 cell bars low to high right hand to left(sitting on bike). Tps is in the middle. I changed the air filter with a new oem one. I take it out for a ride and its running
perfect, no dip in cruising speed throttle response smoother all plusses except I notice my gauge dropping fast 22mpg as compared to the 35 I have been getting and bike is running super rich. Really strong smell of fuel, no leaks I checked. I checked the map and it still the one that was tuned to. I put on a zero map just to see. Now the fuel mileage is climbing back up. Do I need to get it re-dynoed ? Try the tuned map again and run another tank of fuel ? All hoses are connected and tight, pulled air box just to be sure. Would a new filter and a tb sync affect it that much, they were really out of sync when it was dynoed, I now know. Afr was 13.2 when tunedif that helps. Let know what you guys think, thanks.
 
Get it retuned on the dyno for best results.I dont think the PC5 can do what an actual tune can do.I dont see how syncing the tb's would change anything but smoother idle.If the tps isnt adjusted right, that may be an issue.There is a base voltage at idle it has to be set at and if its set wrong will use more fuel.
 
When I installed my Power Commander, I had the same issue. I put the settings (below 4K rpm's), back to the stock settings, and got my fuel mileage back to normal.
 
An of comment about SYNC, but- you smooth it where you want... The idea is to set it how you like. I know people who sync the throttle bodies in three different ways:
1. Per the book. 'nuff said.
2. To smooth a certain throttle/rpm range
3. To smooth and even the pull (predictive pull)

Is that why you set them like the cell bars? So that they actually pull together?
 
I didnt set them like cell bars thats how they were when I threw the carb tune on it. I just checked them per the manual maintenence. They are all level now and were set at idle and stayed even at 3grand. Tps is dead center. I had it dynoed last summer and Im assuming the tb's were that out of whack when I had it done. Only things done since then were new oem plugs, oem air filter. Plugs and filter were over due, I didnt know until after the dyno. Would the tune with the tb's out of sync, old plugs and filter make it run rich now with the old tune map and the new filter and plugs? It feels good, but 12 mpg drop sucks. Thanks
 
I want to say thank you guys for your answers and dealing with my retardedness...lol..some how, some way the breather hose was off. Its good now, went for a ride and all is good. Dont know how I missed it or didnt put it on ! Who knows ! Im just glad it was something easy...
 
I got rid of that hose, put a breather on there and plugged the hole in the airbox.Helped with the idle as well.First thing I did when i got it.
 
Carb Tune is the way to go.
Mine was all over the place when I hooked it up. Runs and pulls very smooth after the sync
Glad you got yours figured out.

Here's my first sync experience w/ the tool. Eazy Peazy...

 
Funny thing though was it was smoother at 2-4 grand cruising through town with the hose off ?
 
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