custom pipe and "jet kit"

[Cassius086]

Hey Y'all...


Got a one-off exhaust system (Mac header and Holeshot Vortex can) for my 82 GS 1100EZ. Got the can new at a great discount b/c it was made from blemished material, and got the header for free. Took the carbs and gave them a thorough cleaning. The fella who gave me the header also gave me the stock adjustable needles and main jets from his GS1100 (which had an 83 Katana 1100 motor installed). So, my carbs now have 112.5 mikuni mains, stock pilots and pilot air jets, and the needles are on the 4th clip with 2 shims, and fuel/air screws are 2.5 turns out. Floats are at stock settings for now. Stock air filter, too. I did drill the slides out, and this seems to help throttle response a good bit. I still have yet to synch them (please don't flame me too badly). Took the bike on a road trip to Indiana from SC and back, and while the mileage dropped some (low 40's compared to upper 40's/low 50's with stock set up). Engine temp never got above 210*. Ran Castol GP 20w50 oil on the way up, and 15w50 Mobil 1 Extended Life on the way back, when the outside temps were 95*F all the way. Despite the lack of a proper vacuum synch, it was markedly smoother at highway speeds. Still a tad lean, I think, as there is a bit of blueing on the header. Do you think this is a good starting point, or have I really cobbled things up?? I am hoping a proper synch job will restore some of the mileage I lost. Again, please don't flame me too badly. Restrict it to words like 'fool' or 'idiot'....:-D

Thanks, guys!!

[Road_Clam]

I custom fabbed my own exhaust also. I am currently running 110 mains, 60 pilots, and .020" shimmed stock needles. I feel I am at perfect jetting for around 75F. My cold starting, and all around drivibility is perfect. I average 43 mpg.

[Cassius086]

Coincidentally, seeing your bike convinced me to look hard at mounting a modern, lighter 'can' type exhaust. Thanks for the great idea!:-D Checked the plugs today, after the long return trip home, and they indicate a lean condition...quite ashen in color. May try turning the screws out another half turn. Do not want to burn up a valve and put a hole in a piston....

Oh, a question I overlooked. The exhaust tip on the pipe is covered in a heavier than expected dark soot. Since plugs indicate a lean conditon, could this be old carbon deposits being burned off the valves due to an increase in combustion chamber temps???