1991 SPI Carb Choice

[kplarose]

Ok guys I have a carb question. I have a 1991 SPI with a Westcoast pipe and a stock single 38mm Mikuni carb. The engine is the yellow 587. I have a spare 1992 dual intake manifold (white engine) and a spare set of dual 38mm Mikuni carbs from a 1993 XP. Would this be a good setup for my 1991 SPI, or would I better off getting a 44mm single Mikuni

 

[derek]

i don't think there is much diff between single and twin carbs. the carb has to fill one cyl at a time. i would go with a single 44 mm from a 97ish GTI. as long as you are trying to make an old 580 go fast, try opening up the RV holes in the case to match the RV holes in the cover that comes with the 720 carb. then go with a bigger rotary valve.