General Category > Quadrajet Carb Talk and Tips
Fuel pressure issue? or volume issue? in a Boat.
Cliff Ruggles:
I hate to sound like doom and gloom and certainly do NOT intend on putting a big black cloud over anyone's project.
Even so I've found that it is better to up front, honest and direct with these things.
Don't know which Holley you bought but I avoid anything from them in the last 25 years or so. I broke my own rules and got involved with a Street Avenger couple of years ago, only because a good friend of mine got it in trade for tree removal (he has his own company). What a complete pile of bovine excrement that thing turned out to be. I told my friend Simon that the next time I saw his dually coming up to the shop for me to take another look at that POS that I was replacing it with a Q-jet. I must have worked on that carb a dozen times as he had nothing but troubles with it. Well the day came and he called me from a job site when his truck wouldn't start. I sent a flat bed for it, got it here, replaced the Holley with a Q-jet Motorhome carb with an electric choke. His fuel mileage more than doubled, instants starts in any weather (the e-choke on the Holley didn't work and was wired open from day one) and the only time I see him now is when he brings me a bottle of bourbon at Christmas time!
I shot some quick photos of what they are currently selling as "Marine" electric choke Quadrajets. They are Frankencarbs and I just toss them on a shelf here, source out an original Marine unit and send that back to the customer. To date that move has been successful 100 percent of the time........Cliff
Pale Rider:
ooof, I`m sick to my stomach now, wish I had found this forum and your book a lot earlier. I spent a good part of the day bouncing around in here reading peoples threads... Def a kick azz take no prisoners forum with fantastic information.
you and Kenth are correct, this looks more like a franken carb every second. I knew when I took it out of the box and the dog leg vent tube was loose, and it did not resemble what I had returned as a core, it was iffy. looks like they used a different main body, but without the provisions for . egr, timing, etc, they used a Mercruiser style throttle base plate, and the top piece is secured with more torx style screws than the slotted that was on the original 17080565 divorced choke variety.
I asked for an electric choke model, and they built one. It does have the Merc style throttle lever base plate, but according to the numbers on the reman body it appears to be a M4ME. from what I can pull from an earlier picture in my file > 17085220, the 7th digit may be incorrect.
just for the purpose of this thread I will take some new pictures of the carb on the boat to show ya`ll whats there.
I am more curious as to why I "thought' I saw the bump indicting it was a large bore casting. ???
lets go back to the repowering the boat for a second. The Seller Lied! no surprise there, the engine was toast despite it ran, I don`t want to waste your time in how I discover automotive gaskets that rotted and caused leaks instead of using Marine gaskets, that`s a good beer story...
The cast iron intake was degraded enough in the thermostat area, I wanted to shed some weight and opted for a weiand dual plane. The Rochester that came with the boat had the very good possibility is was original equipment being only 105hrs on the hr meter for a 1994 boat. At that time I did not want to run it, it was divorced choke and I preferred the electric on the Holley. So I bought a Holley 650 cfm vacuum secondary, the phenolic 1 inch spacer, fabricated the correct length studs and bolted it down. The Holley peformed as expected.
now you say you don`t care for Holleys, I`ve had my bouts with them but for the most part they were ok. the last run on the boat with the Holley had a weird throttle delay when pushed to the point of engaging the secondarys, then throttle creep with the stick in the same position. What I found was a loose enough vacuum secondary housing to cause a small leak and the delay in response, and no doubt earlier closing than what should have been. the electric choke housing was also loose. and I`m like wtf??? So I had this Rochester sitting right here and installed it and ran the boat, and here we are...
BTW, I did not go mazzo on the last ride bc the Misses was onboard, seas were rough and I want to eat if ya know what I mean... so I did not push the boat for max R`s this last time...
with all the changes to the Rochester over the years, I didnt think it was possible to meatball a carb from a bucket of parts and sell t as reman... silly me... its always the honest guy that gets burnt... live and learn...
Cliff Ruggles:
The carb in the pics is one of many I have in the "scrap" pile. Although at a glance it looks like it might be a decent unit it's nothing but a complete pile of bovine excrement and I will NOT use them. Most customers don't even want them back so I have a shelf full of them.
Rochester NEVER used a huge "dog leg" vent tube on the front and it's a bad idea. They fall out easily and hang right over the airbleeds on the side of the airhorn they go into.
Holley made some really good carbs over the years but that all stopped quite a few years ago and I avoid what they are currently selling like the plague.
There are half a dozen companies selling these Quadrajet "Marine" conversions. The biggest outlet is Ebay, and what really amazes me is that they get good ratings so folks jump all over them. Even so, every single one I've seen isn't going to work well if at all.
What I do see is that when I replace one with a real Marine unit the customers problems all go away and they use less fuel. Pretty important these days considering how much Marina's are charging for it.........
old cars:
I have 3 marine carbs on the shelf that I believe to be correct, 17080560,17080561,17080563(restored) 561 and 563 have mapped out the same specs within .001" accept for secondary rods. What do you think Cliff and Kenth
old cars:
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