mercruiser 350 260hp carb

[1970IMP]

Re: mercruiser 350 260hp carb

Swapping carbs is opening your self to a host of other problems.... Jetting, Accelerator pump setting, idle mixture setting, too much CFM, too little CFM.
Its not a bolt on thing! Get your carb rebuilt by a REPUTABLE shop!

I have done this once before on my CJ and i will never do it again. It just never ran right... until i switched to EFI

I just got a Marine Quadrajet for my IMP with 210hp 307 smallblock. Worked right outta the box for $260 with no exchange from........ http://www.i-5automotive.com/page4.html. The have Quadrajets for almost every application.

idle and part throttle performance on a quadrajet is smooth as silk. They had the carb for my exact specs to me in 1 day( I'm not far away though, but they had it UPS the same day)

I swear by putt'n back what came off the thing

Just my $0.02

Joe

 

[illtww]

Re: mercruiser 350 260hp carb

My qudrajet was "rebuilt" also... IT fell flat on its face when i got over 75% throttle also.

Fast forward to now... I put on a Eldebrock 1409 Marine Carb and adjust the Idle screw to around 800 and have been driving it for a week. Loving it! Idles correctly gets outta the hole quick!

Another vote for the ease of the 1409. Make sure you get the fuel line as stated before. We had to do some custom work on my 79' Formula f-20 to get everything situated! I am also running an adapter plate.

 

[knightowl]

Re: mercruiser 350 260hp carb

Eldebrock 1409 Marine Carb "rebuilt version from summit racing" was a great buy... Just dropped it in, took the boat out like 5 times, loving it so far!

 

[buzzlol]

Re: mercruiser 350 260hp carb

.. Thermostat should be 160 degrees. The proper pitch prop for your boat is prolly about a 15" pitch... higher pitch props will overload your engine and cause it to overheat because the engine would be running too low an RPM under high load to pump enough cooling water... you should be able to reach 4600-4800 RPMs max 1 person on board... also, the carburetor won't work right if the secondaries are opening at too low an RPM... check your new carb and see if the secondaries are even opening at WOT/max RPMs/speed...

Pitch ... MPH
15 ....... 30
17 ....... 35
19 ....... 40
21 ....... 50
23 ....... 60

.. Edelbrock makes and sells Rochestor Q-Jet/QuadraJet carbs and Carter AFB carbs now with their Eddy name on them...