The accelerator pump arms on my QF850 hit Performer RPM manifold and I had to use a 1/4" phelonic spacer to get it to fit.

Sooo...a probable 1/4" phenolic spacer (open bore or 4 bores at ? Bore Size), a plate type throttle cable bracket, 3 gaskets (?), the $77 QFT fuel connection kit for 2 feeds, Quick Fuel m-850 (or m-800), and new longer carb studs. Yikes.

Question: What max rpm do you run your boat? I have no intention to run over 4800 (just to keep my goals in perspective).

I've yet to pull the trigger on the QFT, now knowing of the necessary supporting cast. If it was simple carb swap and test run, great. Its not the $800...I'll be saving that with the boat sitting next to my garage. The auto parts store has the 1480 calibration kit waiting for me ($65)...I could give the recalibration a shot 1st, even avoiding the higher rpms through the rest of the season if needed. Then do the new carb off season. At that point I think I'd dump
the air gap and do an hp500 Carb/Intake package from CP Performance (Hardin Marine manifold, QFT 800 btw, and gaskets). For about the same $.

Im running 5200. Summit has a fun little calculator that would get you in the ballpark. I'd only bother with the racing numbers estimate as the torque loads on a boat are too heavy to be considered cruising.

https://www.summitracing.com/experta...cfm-calculator

Before I'd do anything install a wideband monitor before anything else because you should still have it with any new carb as well. I neede one to dial in my carb as well.

https://m.summitracing.com/parts/inn...FUWUfgodMFEAkw

I don't remember what exhaust you have but Wags engineering most likely makes a plate that slips into your riser joint for the O2 sensor.

I think it's real close to being enough carb, otherwise I think I would have also experience it through the prop...it would be nice to have the wideband. Wags site is down, do you space both manifolds or just one. My exhaust was the older wet joint EMI Thunder that I welded up to convert to dry joint with bypass hoses.

You can also send the riser to EMI and they'll weld in a bung. I had someone local weld a bung into my headers which was the easiest way to handle it. Throw the calibration kit into your current carb and see if it makes you happy. Fwiw, my engine ran fine but I put the wideband on it and found that the wide open mixture was good but right at my cruise speed it was lean, and over time may of melted the bugger.

wouldnt welding in a bung be in the "wet" zone?

http://www.offshoreonly.com/forums/g...sor-bungs.html

Results are mixed. Some folks run a few seasons with no problems and others struggle to get a few months out of an O2 sensor. I put an innovate bung extender on mine and ran all of last season with issues. Some people use them just long enough to get a good tune and then forget about it.

Yo Baja Chicken...where should he get those bungs welded in?

F**k if I know. I'm just trying to help the guy out. He should go talk to someone that's qualified.