Ok fellas I need help! I bought a tri power set up on ebay. I have been trying for 2 weeks to get it to run right with no success. The engine will idle although roughly and it will rev up (have not driven it yet). The back carb is dripping fuel into the intake while idling. I have checked for vacum leaks with car cleaner and the engine will smooth out when I spray the center carb at area where the throttle plate meets the main body. Also the engine will smooth out if I put my hand over both of the secondary carbs. I'm thinking the throttle plates are leaking whats your thoughts? By the way I'm on a SBC (383) running a mechanical pump with no guage or regulator.
Well first off fix the back carb dripping issue ,as till you do you are wasting your time/efforts. Bad needle/seat or float level to high.
Buy the kit from speedway with the newbases ,Also how much fuel pressure ,Only about 7 psi.The only reason I say buy the bases If using an automatic Kickdown cable is a problem .Well thats all I know ,Good luck ,
I ran a post on here about the same thing( check under JIMV in search).And what i found on all the carbs was that 1: ball at the bottom of the accelerator pump was missing 2: throttle plates weren't closing enough. I got all kinds of answers about float levels & gas boiling but it was just those 2 items. Usually if you can put your hand over the carb & it speeds up theres a vacuum leak somewhere.But check the balls at the bottom first, its common for them to fall out if the carb is turned upside down. JimV
Are the throttle plates on the end carbs COMPLETELY closed when in the idle position? Were the carbs rebuilt by a competitent rebuilder with experience in multicarb applications? Frank
do you have 3-duece set up or just 3 carbs? it won't run right on 3-carbs fle-bay is full of guys trying to sell carbs as a 3-deuce set up
They are set up to be a true tri power with the outside 2 being secondary carbs. The throttle plates on the outside carbs are as closed as I can get them and I don't have the linkage hooked up. I'm trying to get the center carb to run correctly first but my fear is that the throttle plates that have supposedly been seated and sealed are still leaking. Not to mention one carb is dripping gas into the intake as it idles.
Make 2 solid block-off gaskets for the end carbs, and just run a fuel line to only the center carb first. Get that one carb running perfect first. Then put the original open gasket on the front carb and put fuel to that one and see if the idle is still good. Then, like was said, you need to fix the fuel leaking on the last carb before trying the last carb. Basically, it makes everything easier if you deal with one carb at a time. When you pull the end carbs to make block off gaskets: Flip the carb over to see if there is a gap around the throttle plates. It might be that the plates were not tightened in the correct spot with the 2 plate screws. That would cause the plate to be offset and not being able to seal 100%. The end carb plates need to be "completely" air tight when closed. Shine a flashlight up through while looking for gaps.
somewhere on here is a tech thread on how to use a slight abrasive compound to seat your butterflies, i'll go hunting for it, unless someone finds it first here is one tech thread ,, there are many...this isnt the one i was looking for, but still just type in "tri power tech " and start reading http://www.jalopyjournal.com/forum/showthread.php?t=216531&highlight=tri+power+tech
Again check the ball valves in the pump tubes!1 If there not the the vacuum will pull the gas out of the bowls & it will look like its leaking!! If you take the idle cam screws out or back them off enough on the secondarys that should be enough to be closed.If you have the primary linkage hooked up & not the secondary linkage make sure that the linkage between the front & rear carb isn't set too short & holding them open slightly. Let us know how you make out.If you have to PM me your phone number & i'll explain it over the phone Jimv
This article may (or may not) help: http://www.thecarburetorshop.com/Aftermarkettripowersetups.htm Feel free to call. Telephone is 573-392-7378 (9-4 Mon-Wed central time). I promise not to either laugh, or attempt to sell you anything. And the advice is free. Of course, sometimes free advice is worth what you paid for it! And sometimes LESS! Jon.
I appreciate all your help and I felt obligated to tell you the story and give you all the shortest version possible. After the advice about the check balls was given I decided to tear them apart and see if they were there. Turns out none of the 3 of the carbs had the check balls. Then Dickster was kind enough to offer to help so I called him. After he and I talked for about 30 minues I decided to send my bases to him to rework. So I pulled all the carbs off a started to remove the bases. During diassembly I found no check balls as stated before. I found on the primary carb the guy had just put a new gasket over the top of a partial old gasket on the Venturi cluster assembly. I found that one of the secondary carbs was actually busted in the bowl area behind the accelerator pump. He tried to fix it and conceal it. I found on the other secondary that the gasket that goes between the top and the bowl was actually mislocated to where there was actually almost 1/3 of the gasket down in the carb instead of between it. I also found that all the throttle plates were leaking vacum. After finding all this I called Dickster and he is going to work his magic. The reason that I'm writing all this is that I don't want any other hammers to get SCREWED like I did. I bought these off of ebay. I gave $500 for a set that was supposed to be READY to go. After having several conversations with the guy I bought them from he WILL NOT stand behind them. They are "AS IS". This guy claims that he has built hundreds of sets and never had any problems and his feed back would seem to agree. But all I know is he screwed me so I don't want any of you to get screwed as well. The guy is on EBAY and he sells complete ready to go sets that include linkage and Air Breathers. They are shown mounted on a 3 carb adapter that does not go with the carbs. I don't know if I can get in trouble so I won't mention his name here but feel free to contact me and I will gladly give you all the info you need. AGAIN STAY AWAY FROM THE "READY TO GO" SETS ON EBAY FROM THIS GUY. I also want to say that I could not ask for someone to be more helpful, friendly and knowledgeable than Dickster. I would very highly recommend him.
I'm just getting started fixing a similar sounding setup for a guy. Tri power off ebay, bolted on a perfectly good running engine, all of a sudden runs like shit. Same stuff- throttle plates don't seal, one lid cracked, we'll see what else we find! all tri-powers are NOT created equal!!!!
I have taken apart and rebuilt Tri Powers for Pontiacs for years and I can honestly say I have reworked every piece of them. There are alot of misunderstanding on Tripowers. 1: This is what you always hear. The front and rear carb have to be sealed completely. No they do not and its physically impossible to seal them 100% as even the factory finish between the plates and base are rough. You get them as tight as possible but at the sides, you will always see a small gap when you hold them up to a light. If you see no gap, your plates will stick. 2: If you put your hand over the front or rear carb it starts running smoother, so it must be a vacuum leak. Well yes it is and what you are actually doing is making the vacuum suck gas out of the wells as you just cut off the natural vacuum leak and the engine will suck from wherever it can and when the front and rear is sealed, you will be sucking gas which will smooth it out for a bit but then start running pig rich. I actually have solved a few peoples problems with the Tri Power blues, even had a guy send me $80 which I didn't want but he insisted since he was stumped and couldn't figure out why a customers car ran like crap.He believed in what I said and tried it after reading all the other so called experts posts. He works / owns a Race shop and runs a 7 second car and builds them for clients plus does other necessary work to pay the bills. Anyway, like one post above said, stop the dripping from the rear carb. This is caused by too high of fuel pressure, bad needle and seat, loose seat, too high of a float. After you get that fixed, its now time to work on the center carb to get it to run with the two end carbs that have a bit of a built in vacuum leak. A stock 2GC wont be able to overcome this vacuum source. You will need a couple pin bits. Drill the Idle tubes out a couple thousandths at a time. Also while you have the carb off, drill the Idle air bleed screw holes a couple steps bigger. After doing this, you will notice the idle getting better. I ended up drilling my idle tubes to , I believe .038 when they were stock at .028 Now it fires right up, doesn't stumble, goes like a raped ape and purrs at idle. When you get the carbs back on, depending on which idle air screw you have, you will need to set them at 1 1/2 turns or 3 turns for initial fire up. Get it running and then turn screws in until they run a bit rough and are about to die. Back out each screw till you reach highest RPM or highest Vacuum and then turn back in 1/4 turn. Just a bit of Trivia.... Pontiac used a product called Dag 213 which was a sealing paste when the carbs came in with problems. Only some had problems while others gave years of service. This paste was put on the edge of the plates, then the throttle was slapped shut, opened and then let dry for 24 hours. It was a fast cure but again, you will still have a small vacuum leak no matter what! I also talked with Mike here and he has a great video and a great set of rebuild kits using a ball and seat for the float. They wont ever leak! http://www.pontiactripower.com/index.html He also has Dag 213 which is pretty much unobtainable in small amounts!
There is a thread is titled "Tri power rochester end carbs once and for all" which has a post about lapping in the throttle plates... its #56 and by Tommy. Lots of good info there!
the tri power kits, like Speedway's, come with replacement idle tubes, and a replacement power valve. I bet these two things are overlooked by the average "budget" tri power builder, like the ebay seller above. does anybody have a diagram or picture showing where the idle air bleed is ?
+2 on contacting Mike at www.pontiactripower.com Great guy, great service and a alot of help. -Bigchief.
I'll raise you 2 for 4. Anyone else in? I bought my rebuild kits from Mike. I emailed him at 10:00 PM and at 10:01 he was emailing me back. I give him 100% in customer service and price.
I sell DAG213 on eBay.I use it on all of the tri-power setups that I build for people.The stuff is great.If anyone is interested type in DAG213 on eBay.My eBay name is also oldcarburetors.For $30 w/FREE shipping in the USA gives you enough to do at least 6 carbs,instructions are included.
Hey Old carbs, how about HAMB alliance discounts. You wouldn't have ebay fees either. I'd be intersested in some but not through Epay.
Lots of crap on this thread. first-vacuum leak on sbc=piss poor performance and no idle. second-use new bases on end carbs. Those from Vintage Speed work great, alum. base with brass butterflys=total vac. seal, no leaks. third-like one guy said above, block off end carbs and get it running right, then put one at a time on and be sure it doesn't change. After that, they are fun. I"ve done several sets, including the one I'm running on a 350 with the big base carbs. Well worth it. cooger
Any end base will leak air . It has to as if it were a totally tight seal, the base plate would stick. Hold up any to light and you will see some daylight. especially the sides where the shafts go through. The point being is that Dag 213 will help seal the edges and get as tight of a seal from a metal to metal surface. I actually have the Vintage speed base plates and they show air gaps also if you hold them up to light. If you hold your hand over the front and rear carb, the engine will speed up before it starts to die. This is caused by the air gap all of a sudden not having the air but because there is a vacuum created because of that minute air gap between the plate and base, it will still try and suck . It will start to draw fuel from the bowls at this point and will start killing the engine. So remember. There is no such thing as the end bases sealing 100%. You want the minimal controlled amout of air that you can compensate with the idle air screws from the center carb. I had to redrill the air bleeds to a number 38 to get the Tri-power running smooth and it also took me over 2 years of trial and error after I rebuilt the stock end carbs. Unfortunately, I wiped all the factory DAG 213 off and didn't realize that the dark stuff around the plate /base seal was in fact a sealer. When I bolted on the Vintage speed bases on, it help a bit but was still too much of a vacuum leak for the center to make up for. So thats when I started drilling the air bleeds and opening up the idle slots.
i know, old post, but I've been scouring the web, looking for answers, or at least a direction to go. I didn't know about the ball under the accelerator pump. and yes i put my hands over both end carbs and the idle sppeds up and smooths out. I'm just about set to buy the kit from speedway with the new baseplates, but sounds like I need to do some more looking at what I have first?
also, when I put the centers back on after having the intake blocked off to run on just the center, it runs so rich! Could be pulling fuel out of the bowls, because of the air going by the outer carbs. I'm definitly learning as I go on this tri power stuff. I tried sealing the butterflies better with jb weld, doesn't look pretty and it's not a 100% seal like some guys say you need, but it is better than it was. Still have power valves in the ends, no idea what jets are in any of the carbs. Went back with the same plugs that were in the is engine when I bought it, AC 26 i think. Still have an occasional popping through the exhaust if I have it running then shut it off for 5 minutes or so, then restart it. It'll pop a couple times before it starts. It's really cold blooded too, which seems weird. Takes quite a bit of feathering the throttle to keep it running for the first few minutes after starting it, could be plugs? This is a 302 ford with a modified fuel injection manifold, with rochester 2g carbs. Used engine, don't really know much about it, other than it was in my price range. Mallory Unilite with a 60k volt mallory chrome coil.
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