7 replies to this topic

[Dmartin3093]

i recently traded a hif44 carb for twin hs4s and put them on my 998 and no matter what i did with the idle speed or jet position it just revved and revved the needles in them are (AAU) i have now split the carbs up and just got one hs4 on it now, i dont understand doesnt the size of the carb just mean how much air? would bigger needles help? i would really really like to get them running on my 998 its a 99H block standard block pistons etc and standard cast head, i have a stage one exhust rc40 and other slight mods and ideas guys? would a better head help?

thx

[daenesh]

on a standard or stage 1 998 you should be using single HS4, HIF38 or twin HS2.. anything bigger than that and you will be losing power..

[cal844]

im running a single HS4 with sage1 kit, 2 inch full system

[daenesh]

yup same here single HS4 stage 1 kit.. uprated coil.. 1.5 inch piping..

[J_Durnan]

Twin HS4s are far too big for a standard 998. Even most moderately tuned 1275s are quite happy with HS2s.

[KernowCooper]

As said above really the HS4s are a bit to big for a 998 and as is a HIF44 you would be better off with a pair of HS2s the 1 1/4s fitted to the Coopers and the 1275s as standard and are up for approx 80bhp

[Dmartin3093]

okies thx guys just stick with the one hs4 for now until i get a bigger engine or miht be able to swap the twin hs4s for some hs2s

[ANON]

the 2" exhaust won't help much