[Ronboats]

Does anybody know what jets the list#6109 holley 750 cfm carbs come with originally?

 

[Fiat48]

I wanna say 71 & 80's with power valves...but let me check.

The web says 75's & 76's. But I have to say that doesn't sound right.

 

[Ronboats]

I wanna say 71 & 80's with power valves...but let me check.

Thanks. I'm gonna pull the bowls on my carbs tomorrow and want to know if the jetting has been messed with. Plugs are pretty black looking.

 

[Marcsrollin]

75 front 76 rear and a 8.5 power valve

 

[Ronboats]

75 front 76 rear and a 8.5 power valve

Wow! the jets are nearly the same With a pv? weird.

 

[Fiat48]

Yeah all specs I come up with say the same thing.
We always wound up with 71's pri with power valve and 80's in secondary with no power
valve. Guess that is what I was thinking.
Some guys did 80's square with blocked power valves.

Only the front had a power valve stock.

 

[Ronboats]

And an 8.5 power valve? is there really that much vacuum with dual carbs? Wow! I would never have guessed that high.

 

[Fiat48]

Well....I know a saw a lot 6.5 power valves. Don't recall an 8.5 in one....but that's a long long time ago. LOL

 

[GT Jets]

And an 8.5 power valve? is there really that much vacuum with dual carbs? Wow! I would never have guessed that high.

Nope...Not even close IMHO.....

GT hand

 

[Ronboats]

Nope...Not even close IMHO.....

GT hand

Thats what I was thinking too. Maybe thats why the plugs look black? Motor seems to idle good, but it is new to me, so I think I may try a lower number pv and just see what happens. Course I dont even know whats in them now, I'll find out in the morning. Still seems weird that the primarys and secondarys are so close to the same with a power valve installed.... But sure enough, the Holley web site says 75 and 76

 

[Ronboats]

Yeah all specs I come up with say the same thing.
We always wound up with 71's pri with power valve and 80's in secondary with no power
valve. Guess that is what I was thinking.
Some guys did 80's square with blocked power valves.

Only the front had a power valve stock.

I'll bet I end up with a setup like you are discribing by the time I'm done messing around with it-70 or so in the primarys, and maybe 76-78 in the secondarys. This is a fairly mild motor. Just seems more logical to me to have all four holes flow the same at WOT.

 

[GT Jets]

Thats what I was thinking too. Maybe thats why the plugs look black? Motor seems to idle good, but it is new to me, so I think I may try a lower number pv and just see what happens. Course I dont even know whats in them now, I'll find out in the morning. Still seems weird that the primarys and secondarys are so close to the same with a power valve installed.... But sure enough, the Holley web site says 75 and 76

Depends on which metering block is used too, there are many different blocks and the size of the PV ports vary. My guess would be a very small "Power port". bulb

In a dual toilet app. I would go for a 4.5 or so PV to start with. (closed longer).devil

GT hand

 

[Ronboats]

Depends on which metering block is used too, there are many different blocks and the size of the PV ports vary. My guess would be a very small "Power port". bulb

In a dual toilet app. I would go for a 4.5 or so PV to start with. (closed longer).devil

GT hand

Yeah, I guess changing two things at once wouldn't be to smart. I'll mess with the power valves before making any jet changesbulb

 

[Richard Till]

i`m running two 6109`s on a 468 with a lunati roller pn 50231 since 1990. after several plug readings i ended up running 76 jets on all corners with 6.5 power valves. motor turns 5850 @ wot in a TX19, b impeller. i had forgotten what jets it came with but i`m presently looking in the holley book and it says 75 front, 76 rear with 8.5 valves. primary discharge nozzle size is .025 and secondary is .032 .