Rochester question
 

Is it possible to rework a 454 QJet to work properly on a 350?
Is it worth the trouble?

A friend bought a house boat with 350 Crusaders, it runs way too rich. The previous owner put reman Sierra carbs on but the part# tag is 18-7607-1 indicating that they are for a 454.

Thanks,

Jeff

Try calling Allstate Carburetor (NY) on Tuesday they are great people and will sell you the right parts to fit your specific application. Just know what you have, both carb and motor..
Good luck.

Yes, it is generally a fairly simple procedure to rejet a Q-jet to run on a 350. In fact, I did just the opposite - I rejetted my Q-jet off my 350 mag to run on a mild 454 that I dropped in the boat years ago. I think I still have the stock 350 rods, jets and hangers out in the garage. I'll try to find them and I'll let you know what the codes are if I can locate them. There should be info available online of you do enough digging to tell you what jets and metering rods they ran.

Is is running rich all the time, or just at idle? Do you see any gas dripping out of the primary boosters at idle? If so, this might be due to a power piston that is too heavy for the amount of vacuum the engine pulls at idle. There are a number of other things that can cause this as well. Knowing exactly what the boat is doing will help in diagnosing.

It's rich everywhere.
I don't know if anything has been adjusted. The boat is new to him last year. If it were you, would you try to swap the parts out or get carbs that are already calibrated for a 350? The money is not much of an issue for the guy. I'm just worried it may drag out to a time consuming project that never ends. Throw your wisdom my way.

Thanks for your response.

Jeff

http://www.allcarbs.com/detail.php?p...&ctgn=50&stt=0
$ 299

If money is not an issue then it will be much faster and easier to simply buy the correct carbs. He can probably sell the 454 carbs and get some of his money back.

I have to say Allstate is a great place to deal with. But I do have a Rochester that came off my 260hp 5.7 Mercruiser if you'd like?

JONESFXR how you doing? Got your boat out yet?

No, not yet. I've been working on an old truck for a guy. I'll be bringing the boat home after the truck is finished.

Called Jim at Allstate. Carbs should ship today. I'll have to arrange a booze cruise to test them under real world conditions.
Don't worry the Capt'n will be sober.

That's good to hear, I have a Rochester rebuild manual. If you were going the other route I could have gotten you the OEM rod and jet numbers. What I do know is, the plugs on the bottom, by the primary blades, corrode and leak fuel directly into the intake. Usually all quality aftermarket remanufacturers epoxy them to fix that problem...

Epoxy is only a short term fix. Eventually it degrades and starts leaking again. I think the only permanent fix is to drill and tap the plugs and install threaded plugs with a good gas-resistant sealant.

http://www.hotrod.com/how-to/engine/...et-carburetor/

You could also accomplish this without ordering the kit by simply making your own plugs from a 7/16 bolt - cut the head off and use a grinder to make a slot to screw it in. Then drill out the old plug, tap it, and screw in your homemade plug with some marinetex epoxy on the threads.

Cliff Ruggles' site also sells a variety of Q-jet parts like jets, rods and hangers.

http://www.cliffshighperformance.com/parts.html

I want to go! :ernaehrung004::drink:

Good information. Thank you. Call me crazy, but im probably one of few that appreciates a q-jet. It's like a Rube Goldberg device. :D