New carb or rebuild

[NHGuy]

Did you ever clean the carb and the fuel tank? It's not going to run any differently than before unless you take steps to correct the running problem.
That is, fixing the coupler and etc won't fix the running.

 

[redneck joe]

ok subscribed to anntoehr thread and i feel like if i don't try to rebuild on my own ya'll call me a p..... so going to try.


any tips on ordering the 'correct' kit? n I'm on the road the next few weeks but I do have numbers form the carb somewhere.

 

[redneck joe]

this off another website for a rebuilt one i looked at. I'll poke around here and see what I can find

260 (350cid) 5.7L​ ​

V8​ ​

1978-1982​ ​

4 Rochester​ ​

1347-7362 1347-6492​

17057298 17059288​

Y40-1AN​ ​

$258​ ​

View ​ ​ ​

 

[stonyloam]

ok subscribed to anntoehr thread and i feel like if i don't try to rebuild on my own ya'll call me a p..... so going to try.

You got that right, you must be worthy of the name Redneck
This should cover your carb if it is original. http://www.mercruiserparts.com/bam/subassembly/31737/990/50 and your engine http://www.mercruiserparts.com/260-4-bbl-gm-350-v-8-1978-1982-4908

 

[Pusher]

I'm no motor guy but before you clean your carb maybe you should crack your fuel filter open to see if it has crap in it.

You might not have been able to replicate your motor issues in the driveway because you weren't under a load.

This is probably stupid but can your fuel tank breath? Maybe it's vapor locking after you use some of the gas. I imagine you have a ventline though. You might also check under your rotor cap to make sure you don't have water vaporizing in there.

Stupid ideas I'm sure but thought I'd throw some thoughts in there. I'm having outboard issues right now so I know the feeling.

 

[Pusher]

If there are floats, are there also fuel bowls on this carb? And if there are bowls, are there also drain screws?
My old motorcycle was set up like this and you could connect some clear hose to the drain ports. When you elevated the tubing above the float bowls the fuel would equalize and you could see where the fuel level was, thereby telling you if you needed to adjust the floats up or down.

 

[mickyryan]

not to sound nuts but I wonder if they used the correct gasket under carb, if too thin heat transfers easily into carb causing hot gas problems I remember long ago certain engines had a thick plastic gasket that used to go between I never knew it was for heat until a mechanic told me it was why they used them. Question:
After driving my vehicle for a period of time, and after shutting off the engine I sometimes encounter a hard to start situation (engine cranks over several times before starting) and it usually occurs within a window of 15 minutes to one hour. What can I do to resolve this situation?
Answer:
Chances are you are experiencing heat soak, compounded by today?s blended fuels. Following are some things to keep in mind in an attempt to alleviate this situation.

• Ensure that your fuel line is routed away from your exhaust and or block. This will help alleviate excessive fuel temperature in the supply line that can directly relate to pressure building in the line resulting in the needle and seat being overridden by the pressure causing a flooding condition.
• Remember, heat rises and when the vehicle?s engine is turned off, the rising heat can easily penetrate the carburetor and cause the fuel in the float bowls to expand and eventually boil or percolate.

Resolution:
If hood clearance permits (air-cleaner top to the underside of the hood) then consider installing a heat insulator gasket between the carburetor and the intake manifold. This will create an effective barrier between the hot intake and the carburetor. Here are a few tips when selecting a heat insulator spacer.

• Aluminum spacers offer little if any protection against heat soak.
• Wood fiber laminate, black phenolic plastic and heat insulator gaskets provide great insulation.
• If hood clearance is limited, the following three part numbers are recommended.
• #9265 open design best suited for single plane intakes (.320? thick)
• #9266 best suited for dual plane intakes (.320? thick)
• #9267 best suited for dual quad intakes with 4-hole style carb pad quantity of two (.125? thick)

For additional heat insulators in sizes from 1/2? ? 2.00? please visit this link on our website. http://www.edelbrock.com/automotive_new/mc/install_items/adapters_spacers.shtml.

 

[Pusher]

That's interesting info

 

[redneck joe]

well micky now that you mention it; I did find a gasket that looks like its for the carb. It was behind the battery.......

but - it was doing the issue when i paid them to rebuild last time, then it ran find for a few times that I was able to get out after that so i'm leaning to the poor rebuild. But they also had the motor out (twice) in relation to the transom redo so maybe they stepped on the fuel line and its sitting on the block now because if I remember the issue didn't start until the thing came out....


pusher - yeah all good on those possibilities.



I'll check when I get home this weekend. Thanks for the tips.

 

[NHGuy]

Get a kit and probably also get a float. While it's apart test the vacuum pot by pushing in the link and then put your finger over the vacuum hole. If it stays in you are good, if it comes out get a new vacuum pot. On my 88 that was bad, and causing issues.

And get the vacuum hose for it. Just get a little bit of vac hose on line. Don't try to use washer pump hose it won't hold vacuum like the thicker real vacuum hose does.

There will be too many gaskets. As you take apart the carburetor, match up which to use by comparing to which gaskets are coming off.

 

[boatman37]

i replaced my choke pull-off. i assume my old one was good but for a few bucks extra why not? and yes, you will have several extra gaskets left over. just take plenty of pics along the way. as long as you get it good and clean and get your float level set right and reassemble the same way you took it apart you should have no problems.

mine only came with the thin base gasket. on cars i always used the thicker (~1/4") base gaskets but this kit only had a thin one and the old one was thin so i put the thin one on. no issues with it.

i also JB welded my fuel wells. not really necessary but you can google it and do it if you would like. the problem is the plugs in the bottom of the fuel well can start to leak dripping fuel into the intake after you shut the engine off. makes it harder to start the next time out cause your fuel bowl is empty. just need to get a file and rough up the surface and dab a little JB Weld on it but not too much cause it may interfere with the throttle plate when you reassemble it.

and you have to remove the air filter stud to remove the top of the carb (air horn). it threads through the air horn so you won't be able to get it apart with it in there.

you will likely need 2 or 3 cans of carb cleaner

 

[trebot]

Went through the Quadra-Jet rebuild merry-go-round myself. Finally bought a new. EDELBROCK Marine carb. Performance, smoothness and fuel economy noticeably improved. Great investment !!
May want to check fuel system for Ethanol phasing gunk.

 

[30 Commander]

Rochester quadrajet in the picture....fantastic carb when set up properly....way better imo than any aftermarket Holley or edelbrock.
etc.
I rebuilt 2 of them last winter that were 25 years old. Not hard to do at all. I highly recommend you google Cliffs Performance. This guy is the king of quadrajets in the country. He will sell you a nice high quality rebuild package including all the replaceable parts to get yours running like new again for around 45 bucks. Really nice thicker gaskets between the bodies. Best kits on the market believe me! Great customer service as well. Better yet, call him and he will tell you what you need.

Oh yeah, don't JB weld the fuel wells, thats asking for trouble in the future. Cliff has a neat inexpensive package that has screw in plugs to replace the old casting plugs.

My twin 5.7's love their quads....purrrrr like kittens.

 

[NHGuy]

I second Cliff Ruggles. His book is called something like Rebuilding and upgrading the Rochester Quadrajet. It's on SA books. It's awesome. His website is called cliffshighperformance dot com.
I have a buddy's quadrajet in my basement right now that I am going to put back together and try out on my boat. The boat has the OE 600 CFM Weber that came on it's 350 Mag. I've jetted it all up, but I need to try that extra cfm the Quadrajet has on my updated engine.
Quadrajets are very nice, you won't regret it when you are done. The hotrod guys claim they make more power than an equivalent Edelbrock, which is the same as a Weber or a Carter AFB or WFB.
AFB=aluminum four barrel
WFB=Weber four barrel

 

[30 Commander]

Cliff Ruggles...thats right....cliffshighperformance.com......he's an expert on Quadrajets.
The book is excellent and very in depth, and explains every detail of the quadrajet and its operation.
Also of note is the forum on his website where almost every Quadrajet problem is discussed and Cliff spends lot's of time answering and diagnosing problems.
That's where I got most of my questions answered.

 

[Jcris]

Redneck Joe,
How's the carb rebuild going?
Jcris

 

[redneck joe]

Wel kinda got put on back burner. U eected trip to south mississippi for a funeral and simce i was that far south visited my new territiry, nola and spent the week driving home visiting other shopz.

I've decided to pull a typical joe, and uy a rebuilt and a kit. Slap the rebuilt on to get in a couple trips thi

 

[redneck joe]

To finsih.....



This year. Rebuilt over winter and have a spare for what thats worth.

 

[redneck joe]

ok new question same subject.

I cancelled my rebuilt order due to not receiving it after three week. Was then going to order from flying fish carbs - he had one in his hand and would be two day ship but....

Either way I'm going to get the boat out one or two more times this year, since it runs, just not well when hot.

Talked to my guy and he a proponent of switching to Edelbrock. It will take a new fuel line (no biggie) a spacer to bolt on or I've seen recommended to change intake manifold but in my quick internetting I didn't find one that would fit my 79 model but who knows. Regardless that's more money which really isn't a problem, just is it worth the time and effort. He said, and I've seen here on the forums that it help fuel consumption and maybe a better top end - one guy stated he had to change props to stay in limits. And it is more 'stable' with less issues.

 

[Rick Stephens]

I switched from a QJet to a 1409 Edelbrock. Be a long useless story on why I switched. One nice thing, it takes me a long time to do a QJet rebuild, I can do a 1409 in nothing flat. REALLY easy to work on and a lot simpler to calibrate than almost any other carb.

I went with a Performa intake from Edelbrock. I think the 2101 would be right for your pre-1986 SBC. More info on this page. The 2101 is one from the bottom.