Hi folks, I'm currently restoring a 1982 CB750F Supersport and having now rebuilt the engine I am test fitting a new set of Mikuni carbs and found and have run into an issue.
From memory the carb spacing of the OEM KeiHin carbs (now sold) was 80-100-80 at the inlet of the rubber boots. As these were severly perished they were cut off and replaced with a set of rubber boots sourced from Ebay purporting to be for all CB750 DOHCs from 79-82. However when installed the inlet spacing is measuring 90-90-90 making them unusable.
Never one to give up, I purchased a second set of inlet boots from a more reliable source at around 3x price of the Ebay specials. When they arrived, they looked identical and to my surprise also measured 90-90-90 on the bike.
My question therefore is this, what is the inlet spacing supposed to be, 90-90-90 or 80-100-80??
I purchased the Mikuni carbs directly from Mikuni and they quote the spacing as 80-100-80. Have I just been unlucky and bought 2 sets of incorrectly labelled inlet boots?
Photo is of inlet boot set #2 with measurements
From memory the carb spacing of the OEM KeiHin carbs (now sold) was 80-100-80 at the inlet of the rubber boots. As these were severly perished they were cut off and replaced with a set of rubber boots sourced from Ebay purporting to be for all CB750 DOHCs from 79-82. However when installed the inlet spacing is measuring 90-90-90 making them unusable.
Never one to give up, I purchased a second set of inlet boots from a more reliable source at around 3x price of the Ebay specials. When they arrived, they looked identical and to my surprise also measured 90-90-90 on the bike.
My question therefore is this, what is the inlet spacing supposed to be, 90-90-90 or 80-100-80??
I purchased the Mikuni carbs directly from Mikuni and they quote the spacing as 80-100-80. Have I just been unlucky and bought 2 sets of incorrectly labelled inlet boots?
Photo is of inlet boot set #2 with measurements
