Dominator Carb tuning
07-12-2016, 12:10 PM
#1
Dominator Carb tuning
OK, I have dual Dominators on blower motors with really tall gears and I have some serious dockability issues. Not fun being around the docks with $500k+ boats when a motor dies shifting into gear. I learned how to tune a 4150 a while back so hopefully that will help.
So, first setting the idle, do I only adjust the primaries (dominators) and back the secondaries all the way off?
Do I enrich the idle mixture screws to attempt to attempt to keep it running?
I noticed that the accelerator pump adjustments were at 1/8th inch gaps, can this be right? They do not seem to be all adjusted the same either. I thought the way to adjust them was like .010" gap on the lever?
I also was talked to about adding solenoids to the accelerator pumps to bump them when it is put in gear. I have heard Dave Wesseldyke and Sterling use them.
So, first setting the idle, do I only adjust the primaries (dominators) and back the secondaries all the way off?
Do I enrich the idle mixture screws to attempt to attempt to keep it running?
I noticed that the accelerator pump adjustments were at 1/8th inch gaps, can this be right? They do not seem to be all adjusted the same either. I thought the way to adjust them was like .010" gap on the lever?
I also was talked to about adding solenoids to the accelerator pumps to bump them when it is put in gear. I have heard Dave Wesseldyke and Sterling use them.
07-12-2016, 12:11 PM
#2
OK, I have dual Dominators on blower motors with really tall gears and I have some serious dockability issues. Not fun being around the docks with $500k+ boats when a motor dies shifting into gear. I learned how to tune a 4150 a while back so hopefully that will help.
So, first setting the idle, do I only adjust the primaries (dominators) and back the secondaries all the way off?
Do I enrich the idle mixture screws to attempt to attempt to keep it running?
I noticed that the accelerator pump adjustments were at 1/8th inch gaps, can this be right? They do not seem to be all adjusted the same either. I thought the way to adjust them was like .010" gap on the lever?
I also was talked to about adding solenoids to the accelerator pumps to bump them when it is put in gear. I have heard Dave Wesseldyke and Sterling use them.
So, first setting the idle, do I only adjust the primaries (dominators) and back the secondaries all the way off?
Do I enrich the idle mixture screws to attempt to attempt to keep it running?
I noticed that the accelerator pump adjustments were at 1/8th inch gaps, can this be right? They do not seem to be all adjusted the same either. I thought the way to adjust them was like .010" gap on the lever?
I also was talked to about adding solenoids to the accelerator pumps to bump them when it is put in gear. I have heard Dave Wesseldyke and Sterling use them.
07-12-2016, 09:53 PM
#4
Registered
iTrader: (3)
every dominator i have seen was 4 corner idle so closing the secondary blades will cause problems.the idle mixture screws can be touchy,close them all the way in and then back them out 2 turns.try to open primary&secondary idle screws the same amount[around 1 turn to start]acc pump arm gap of .010 is good.
07-13-2016, 09:48 AM
#6
Platinum Member
Platinum Member
Just having stalling issues coming in and out of gear? or do you have "lope" problems once in gear?
Is your timing locked out? If not, do you know where your centrifugal advance starts coming in, and is there a chance that your timing could be wandering at mid-idle speeds?
Are your carbs boost referenced? If not, do you know what Power Valve "sizes" you are running (it's a number that corresponds to vacuum signal).
You want to keep the timing AND the fuelling circuits DEPENDABLE around the docks, and any timing changes or powervalve variation will make life miserable.
Outside of those, there is still the shifting issue with steep props.
What transmission are you running? If you are running a tranny that USES hydraulic pressure to clamp the clutches, then you can install a pressure relief to allow clutch slippage at idle. Most of the Velvet-Drive clones use springs for the clutches, which won't do what you want. But at least holler and let us know what transmissions you are using. Might still be something that can be figured out.
Is your timing locked out? If not, do you know where your centrifugal advance starts coming in, and is there a chance that your timing could be wandering at mid-idle speeds?
Are your carbs boost referenced? If not, do you know what Power Valve "sizes" you are running (it's a number that corresponds to vacuum signal).
You want to keep the timing AND the fuelling circuits DEPENDABLE around the docks, and any timing changes or powervalve variation will make life miserable.
Outside of those, there is still the shifting issue with steep props.
What transmission are you running? If you are running a tranny that USES hydraulic pressure to clamp the clutches, then you can install a pressure relief to allow clutch slippage at idle. Most of the Velvet-Drive clones use springs for the clutches, which won't do what you want. But at least holler and let us know what transmissions you are using. Might still be something that can be figured out.
07-13-2016, 10:46 AM
#7
Stalling issues when put in gear, the lope at idle does not bother me and is nonexistent when in gear.
Timing is locked as it is a MSD crank trigger system and doubt there is any way timing could wander.
I do not recall seeing a boost reference line going to the carbs so assume they are not. I have not had any bowls off so I have no idea of powervalve size.
I do have true velvet drive transmissions and would appreciate the pressure relief info. Ill have to do some more research.
BTW 32 pitch props and 1.24 gears.
Timing is locked as it is a MSD crank trigger system and doubt there is any way timing could wander.
I do not recall seeing a boost reference line going to the carbs so assume they are not. I have not had any bowls off so I have no idea of powervalve size.
I do have true velvet drive transmissions and would appreciate the pressure relief info. Ill have to do some more research.
BTW 32 pitch props and 1.24 gears.
