VintageVmax.com

Hey Guys i followed the porting specs as listed in the arcticals lower intake 4 mil ext. . . I got my V max running today it had 290 jets in it to begin with i figured with the porting i should go up so i went to 320 , got it started but it would bog the whole way , So i went into the shop and looked at the plugs , REALY black , So i moved the carb needle jet to the top clip to lean it out , After that It will still bog from 3800rpm - 4400 rpm then it kicks in hard and goes realy fast , and the plugs look good , what do yous think i should do , , , i was thinking maybe 300s and move the needle to the stock middle grove ?
Any help would be great
Im sure some one on here has used these porting specs
Thanks
Chris

Chris,
Altitude, Temperature, humidy, engine condition, quality of gas, ect... all play a role and few are the same. Sounds to me like I'd try the 300's and recheck the plugs !

Chris if you are referring to the update porting in the article section, according to my 85 mechanics guide on 84 and 85 model year V-Max's no jetting changes are necessary.
and on 83 model V-Max's changes need to be made. (see pic)
I would use egt guages if possible.
I always check spark plug burn to make sure my gauges are reading accurately.
Hope this helps.....LMK

Thanks guys , , , My cylanders are 8u9s and the base crank and care are a 81k , Is it still nessessary to mix your gas too ?