My 1050 dominator has power valve plugs. The 750 XP series I'm working on has 4.5 power valves on both ends. Both are alcohol carbs. Just wondering if I should leave the power valves in the 750 or put plugs in? I have not run this carb yet, just going through it as I got it second hand.

My opinion on power valves in an alcohol carb is that they don't hurt but aren't needed as likely as a gas carb. You can be off on tune with Methanol and not really cause issues that would be much more pronounced with gas. All that said if it worked before I don't see any reason that it wouldn't work as is.

They're both in good shape and I assume the carb worked as intended initially.

If I opt to remove and plug them, does the same plus 8-10 jet sizes apply on an alcohol carb like it does on gas?

The only two I’ve run into with power valves we left them in so I have no data to say. One was a Pro Systems and I’m not sure on the other. My personal carbs I haven’t run one in to say what the change would be either.

Luke Bogacki (Apologies to Luke, I believe I may have miss-spelled your last name) did a video on the APD Max Flow 1250 Dominator that uses a power valve in the primary metering block. I have one of those Dominators as well as a Carb Shop 1050 that also uses a power valve in the primary metering block. The logic behind using a power valve is explained in Luke's video. Simply Google APD Carburetors and look for Luke's video.

Both carburetors are excellent in bracket and .9 Index racing, they have many tuning options using power valves and are very consistent.

Bob

The thing with a rear power valve is that it will become uncovered on a hard leaving car. Thusly, remove the rear valve. My experience with a front valve is good because engine is sharper at part throttle. It is most noticeable with Methanol to eliminate the "blubbering" at part throttle.

power valves are for street cars

Maybe I'll put a power valve in the front of the dominator and pull the rear one out of the 4150.

I'll ask again, does the same 8-10 jet size apply to an alcohol carb if the power valve is removed like it does on a gas carb?

If the 4150 had PV's leave them, depending on what metering blocks were used they may need them to get enough fuel in the carb. Without going thru it I can't tell you what it would need. Dominator will probably not have the same issue, leave them plugged. And the removal of the PV will depend on the PVCR size used as to how much larger the jet needs to be.

The APD Max Flow 1250 Dominator I have uses a primary side 4.5 power valve that has small restrictions/jets under the valve. These can be altered however I wouldn't recommend it unless you had the means to quantify the results.

There are a lot of "Do's and Don't's" with power valves,they can be very beneficial if you know what you are doing, and how and if you need to install them.

Bob