HOW TO: Testing a Power Valve
Автокөліктер мен көлік құралдары
This video briefly explains the purpose and function a power valve, what happens when one fails or "blows out" and how to test a valve to determine viability.
The power valve and the power enrichment circuit are critical parts of any carburetion system to allow for proper fuel delivery at wide open throttle or very significant open throttle positions.
Being a vacuum operated device, that controls fuel flow, it is critical that a power valve be able to maintain vacuum pressure and operate with a leak-free diaphragm.
A failed power valve will lead to unmetered fuel entering the throat of the carburetor, makes tuning impossible and the extremely rich running engine will also suffer from poor performance, acceleration and gas mileage.
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Good video; best explanation of the power valve yet.
Great explanation, thanks for the upload, very clear, now I can test my Holley power valve, see if I can solve my very rich Idle and poor fuel mileage on my 327 1965 El Camino, cheers from Melbourne Australia
Thank you for simplifying the power valves role in a finely tuner carburetor.
Bingo! Just discovered this very issue last night. First time the car hasn’t run too rich ( ie- run right) in the 2+ years since I bought it. Jeez! If only I knew in the summer of 2016 what I just learned now. Everything you described in your video is pretty much a sad tale of myself going down the rabbit hole, and chasing ghosts. Was so nice to feel the car drive right.
@ctuan13
6 жыл бұрын
Hey man, I'm glad to help! So glad it fixed your issue! That's why I knew I had to make this video!
1979 Lincoln Continental?! Good man, good man!
@ctuan13
6 жыл бұрын
Yes I do! She's actually featured in my latest video on the Cat S61's built-in thermal camera! kzread.info/dash/bejne/aoakqLx-hLqpo9I.html
Hey buddy great explaining to the power valve thanks
Well done! Thank you for this information. If you are able please do more like this one. So many how to videos skip the details and details are the killer bee. You nailed it!
@zaneking7102
2 жыл бұрын
I realize Im quite off topic but do anyone know of a good place to watch new series online?
@westinkamari5560
2 жыл бұрын
@Zane King meh I watch on flixportal. you can find it if you google =) -westin
@zaneking7102
2 жыл бұрын
@Westin Kamari Thanks, I went there and it seems to work =) Appreciate it!
@westinkamari5560
2 жыл бұрын
@Zane King you are welcome =)
great explanation ! just blew mine on a Holley
Genius, saved me $50 buying the Moroso power valve tool.
the best 2v ever made. Good vid on PV. Wanna no if U got 1 onda H/W 5200, "pinto carb" or Weber 32/36 (all the same)...will scan around 2 find...
Great video, thanks !!!!
@ctuan13
4 жыл бұрын
No problem! Glad you found it helpful!
The header on your KZread channel has a mint Lincoln, bro!!
Just removed the power valve from the carburetor on my 1965 Ford Mustang. Everything seems dry but have been experiencing all the symptoms. Could it still be the issue? Gonna change it while it’s out anyway and see what happens.
Thanks for video. But what watch are you wearing?
Also, be sure to get ethanol-free gas like "recreational gas" for snowmobiles. Because these carbs and the rubber parts, they were engineered way before they started putting ethanol in the fuel. The ethanol can be hard on 'em, so use ethanol-free.
@TheThirdWheel618
Жыл бұрын
We're are you going to get that ? Are you talking about the racing unleaded that has no ethanol in it ? Man that stuff we're I live is 25 bucks a gallon .😳
Nice demo.
@steveharrington8788
7 жыл бұрын
jack tietjen does the power valve affect the take off cause mine runs well except for the take off it bacfire is my power valve blown ,what might be wrong
@ctuan13
6 жыл бұрын
A power valve really only comes into play when the throttle is opened greater than 50%, certainly it isn't playing any kind of roll right on throttle tip in. Remember, a power valve is closed when vacuum is high. A backfire on acceleration can be a lot of different things, but some basics are checking for a vacuum leak, checking to ensure idle mixture screws are set correctly and checking for a restricted exhaust. Hope this helps!
FYI, the brass piece sticking out a little bit on your new valve is the adjuster......
8:15 I kept telling sparkplug boot but you couldn't hear me so I said it here. I'll find out if one works because I need to rebuild my carb soon
#1 in canada has oxygenics for octane , regular has 10% ethenol hard on power valves , marine grade (SHOULD big word) have no alcohol less water dillution sitting at the dock
Thanks for the video 🙂 I have a 600 Holley on my 69 F250 390 and my idle circuit was acting like an A$$ today . I have a big ol bag of different size power valves and I reuse them until now . I'm going to test them all I would come to a stop light and the mixture would just slowly get richer and richer, I start out at 13 AFR and end up at 10.5m 😳 . Go to take off runs like a champ till I stop again then it shot up to 14/15 🤔. Turn the screws get it back to 13 then next stop light it's at 11.5 ? 🥺 Maybe the old gaskets I use too I already had a stuck secondary needle and seat and jetted up 10 sizes before I realized it was sticking . This gas is no good for carb anymore maybe go efi ..
Thanks , there's hardly anything on Moto carbs ,
My valve was stuck with varnish. I'm going to replace it but just for fun I tried to unstick it. Soaked it in carb cleaner for 4 hours and pressed really hard on the end and then it snapped open. Required a ridiculous amount of force.
Do those have numbers on them for the amount of vacuum that they open like the holley type?
@ctuan13
7 жыл бұрын
Unfortunately these ones that come in kits don't usually come with numbers. Although if you know the number power valve you need, you can get it from Mikes Carburetor Parts online. He's got both single and two stage valves available in tons of different vacuum values.
@nobamagone1063
7 жыл бұрын
kwd57 they have the numbers. Holley parts. I swear that the valve was so weak it was open at idle
If you follow Holley's recommendations for power valve selection; you will have what appears to be a blown power valve because the engine won't die with the mixture screws seated. But; this occurs because the valve is to weak and its open at an idle. I had a 6.5 power valve because I used Holley's instructions. 13 inches of vacuum at idle so 6.5 valve. The Spark plugs were black. I installed a 10.5 and now it's closed at idle as it's supposed to be. I don't know why Holley is still teaching that 1/2 of idle method, it's wrong.
@jimdavidson5208
6 жыл бұрын
The half deal is a good ballpark setting for most carbs. Actually it's not at idle but CRUISE vacuum. So if you are at say 40 MPH and you have 14 inches of vacuum, try a 7 or next lower power valve.
@MrDLRu
3 жыл бұрын
@@jimdavidson5208 Hey Jim...You don't have a clue what you're talking about. It's at IDLE, not CRUISE vacuum.
@MrDLRu
3 жыл бұрын
Holley didn't tell you to seat the idle mixture screws, so maybe that's your problem. You should watch their video again.
@vinced2514
2 ай бұрын
nobamagone1063 - The scenario you describe doesn't make sense; a 10.5 PV will open sooner (closer to 13 inches of vacuum) than a 6.5 PV. Doesn't seem likely, but maybe the 6.5 PV was bad (blown or leaky). I agree with jimdavidson5208 that the half vacuum reading is a good place to start, but the reading for that method should be done at idle. A better method is to note the vacuum reading at steady part-throttle cruise speeds and use a PV 2 steps smaller than the cruise-speed vacuum reading (or 2 and a half steps smaller if 2 steps smaller lands on an even number).
Geez thought this was a how to. Damn son get to it god
Yeah lincoln are great
I have a 72 mark iv and have been battle the carb and runs rich no matter what I do, it's a 4 brl Moto, so should be same from what your saying no matter 2brl or 4 brl right?
@ctuan13
5 жыл бұрын
Yeah the power valve could very likely be the culprit! Check out my latest video on fixing power valve issues if your new power valve gasket leaks. kzread.info/dash/bejne/m3x8ytSEppjTc8Y.html
@ryanc.1784
5 жыл бұрын
@@ctuan13 have u ever done a video on Moto 4 brl everywhere I search you find a little this or that but nevr what will help and in the comments are tons of ?'s, thanks again much appreciated
Can a blown powervalve cause the motor to stall?
@ctuan13
6 жыл бұрын
Potentially, if the leak is bad enough and there is enough fuel being sucked through and bypassing the power valve, it could flood out the engine and cause it to stall.
@Skankhunt-og5md
6 жыл бұрын
COPPERHEAD GARAGE I wouldn’t see why not if there’s a immediate lack of fuel
Hey buddy can I just replace my two stage power valve whit a single stage?
@ctuan13
4 жыл бұрын
For sure, you can always replace a dual stage with a single, just make sure you find the proper value valve. For an automatic, put the car in drive and get a manifold vacuum reading. Divide the value by two and select that value valve. If it falls on an even number, choose the next lowest value valve.
エンジン始動中にアイドルミクスチャーを全閉にしてもエンストしなければ、パワーバルブのダイヤフラム破損又はバルブ機構の動作不良と判断。
Vacuum systems do not bleed, they vent.
What's with the medical gloves?