has anyone had any adverse effects of installing jet extensions in a 4150 holley? i have a weird lean prob. on the rear barrels and i think it because of the extensions. i installed the notched float kit back in may and have noticed what feels like 1 barrel shuttin off ,then back on.floats are set rite, i rechecked 3 times(electric pump) and when the mill lean stumbles, it still has 7psi(had someone watch it). anyone had these probs with extensions?is it not able to get enough vaccuum reference to the booster to start pullin the fuel threw the long extensions?
I run secondary jet extensions in all my Holleys and haven't had this problem, BUT, I have had problems with the phenolic floats not clearing the extensions and hanging the float up. Particularly if you have a Moroso ext kit and Holley float, etc. One question.... you do run a "whistle" in the primary bowl vent, right?
I run secondary jet extensions in all my Holleys and haven't had this problem, BUT, I have had problems with the phenolic floats not clearing the extensions and hanging the float up. Particularly if you have a Moroso ext kit and Holley float, etc. One question.... you do run a "whistle" in the primary bowl vent, right?
do you mean the plastic thing that extends off the meter plate? i'll have to check, i can't remember it havin them.the notched float kit is holley brand as are the extensions.its drivin me nuts trying to get this rite.what will not havin the "whistles" effect?
A whistle will help keep fuel from sloshing up thru the bowl vent on the primaries on accel, and secondaries on decel (not as big a deal on a boat, or maybe it's just the way I drive :rollside: )
Under what conditions do you feel it leaning out? On accel, leaning out after a second or two, decel, turns?
i run "whistles" as RW suggests with no ext's & have never had a prob...i also run 50cc pumps...do u have them??...might be ur prob...not getting enough fuel to the secondaries...just a suggestion
fastrat
i run "whistles" as RW suggests with no ext's & have never had a prob...i also run 50cc pumps...do u have them??...might be ur prob...not getting enough fuel to the secondaries...just a suggestion
fastrat
let me try and desribe what it does:
if ya wot it surges like 1 complete barrel shuts off
seems like if you hit a wake it'll clear up?
i looked up the jets and pumps for a marine 850 dp holley and it said the jets recommended to start off with where: 88 pr. 94sec. with a 30cc up frt. and 50cc in the rear. so i jetted mine to 84 in frt and 90 in the rear with the extensions.i also have my 50cc pump on the frt and 30cc in the back. it seemed to run well all last season like this and i can't think of anything other than a valve spring change that i've changed since then.checked the plugs and they look nice , color indicates good fuel mixture and timing.any idea??????
fastrat, i might threw a 50cc in the rear too.i like to have it alittle rich up frt. when i drop the hammer with the no2 and use the 50cc frt. pump for that.
also i changed power valves last weekend trying to fix this condition.i run 50% avagas,50% super.
Since this happened after the spring change you may want to check the spring pressure.You could be floating the valves.
It sounds like a float/needle valve problem to me. Yes, I've had needle valves hang up right outa the box. What's you fuel pressure at WOT?
It sounds like a float/needle valve problem to me. Yes, I've had needle valves hang up right outa the box. What's you fuel pressure at WOT?
7PSI, i have a fuel pressure safety switch on the fuel rail that shuts down the no2 relay if pressure falls below 7psi.i've also had my uncle watch the pressure gauge at wot and he said it stays between 7-8.the needle and seat may be the trouble. i'll check em out.
502, the seat pressure is 115-120psi to open and open pressure is 340psi.i don't think i have any more spring probs, i checked pressure again after spring change and @ 4hrs on the new springs and they still have the same amount of pressures.i bought a moroso lever type pressure gauge and i compared it to my uncles high dolla one and they match.
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