I suspect my brake booster hoses leak and want to find the size in order to replace them, I know they are the original hoses as they are rock solid and have Japanese text on them, and want a metric size hose and not the somewhat sized standard hoses.
Also Is the soft hose that brings gas into the carb 5/16 or 1/4th ? I recently put in 1/4th and the car seems to bog down until it warms up . I suspect the old hose was 5/16 .

 

The fuel hoses are 6mm and 8mm. 6mm is close to 1/4".

 

So the inlet hose is 1/4th and the outlet one is 8 mm ?

 

Inlet is 5/16 and the return is 1/4.

 

Thank you ! I only changed the inlet hose to 1/4th and it caused me a great deal of issues but had no idea if it was that or a clogged cat since the symptoms are very simmilar . I purchased the right hose.
Edit : God dang , this minor change made the world of difference , the car idles better than my brothers 97 accord now ! Not a single bog when cold either and at temp id get micro bogs that werent really an issue but now they are GONE . I previously had 5/16 and 1/4th on the inlet ( i have a fule filter spliced in) and the 5/16 hose developed a split , I replaced it with 1/4th and the car became borderline undrivable until it got to temp and even then there were bogs under 1700 rpm.. Before this id bog on cold days or pre warm up .. Today the car not only fired right up without the choke ( it was 95 deg out so that doesnt really matter ) but the idle was super clean for the first start in 5 days.. Thanks guys .. What a rookie mistake that had been making my car worse for over a year.. That extra four inches of 1/4th really put the nail on the coffin when combimed with the existing 5 inches i already had in there.. Now its 8 unches of 5/16 and she purrs..