Holley carb. Have put a rebuilt holley 600 on my 350 boat enginecant get it to idle properlyif you rev up to 1500rpmslowley decr

muffycaz, Aug 19, 2:38am
Have put a rebuilt holley 600 on my 350 boat engine.cant get it to idle properly,if you rev up to 1500rpm,slowley decrece surges a bit then idles.If you decelerate rappidly it cuts out,have sent it back and being told it should be alright.any ideas,cheers grant.
kingfisher21, Aug 19, 2:41am
Who rebuilt it!
rob_man, Aug 19, 2:41am
Temperamental sons of bitches they can be. Put the original Q-Jet back on it.
Could be the idle mixture's a little lean.
clark20, Aug 19, 2:46am
A feature on later carb vehicles before EFI was a throttle damper, which slowly closed the throttle for the last 1/4 or so, they did this for emissions however one of these dampers may help your cause
muffycaz, Aug 19, 2:50am
I live on the coromandel ,brought it from gisborne.Original Q jet worked well.Was told that holley was more ecomnical.
extrayda, Aug 19, 3:00am
muchly though I like Holleys, I wouldn't expect it to be more economical than a decent q-jet. Assuming the Holley is probably a square bore vac sec!
extrayda, Aug 19, 3:00am
Or is the Holley one of those silver ones with gaskets above the fuel line etc!
muffycaz, Aug 19, 3:04am
vac secondary.
extrayda, Aug 19, 4:17am
Are all four of the 'holes' in the carb the same size, or are there two small ones and two big ones! (squarebore = all same, spreadbore = 2 small primaries, 2 big secondaries - as per the q-jet). Did you fit the holley onto the old intake with an adapter of some sort! Apart from not idling does it run fine! Could be something as simple as winding the fast idle screw in!
sr2, Aug 19, 6:29am
+1; great advice, keep it original or spend the bucks and put a Demon (or similar) on it.
74nova, Aug 19, 1:46pm
Nothing wrong with Holley carbs. its the only carb I've ever used, easy to tune up.