I also use the NGK works great..as long as you keep the 02 dry !

So where can you put the bung and keep things dry?

They go in the risers, I talked to Stainless marine and they will install them, but I called Orlandi performance, and they will do it for $100 plus the cost of the bungs. They are about 20 minutes away, so it saves the shipping hassle.

I am running Stainless exhaust, on 454 with 177."s. I burned a motor last year. But before I put the motor back in I had it dynode tuned. Well now after reading your post, I really think I need the AFR readers in my boat,.

Where should I have the bungs welded on my exhaust.

Thanks Steve

I also had mine dyno tuned. Even the person I had dyno it said I should get them installed. We left it a little rich off the bat, so I am going to drop a size right of the bat on the secondaries. I want to monitor my cruise AF ratio, seems like I use a LOT more fuel than I should compared to when it was stock, my guess is it is is WAY fat part throttle (3000-3300rpm).

This thread also pushed me to finally do it.

dyno tuning will get you in the ballpark but yes you need 02's to get dialed in right, dyno's are not running down the river for long periods...

What size or style fuel/water separator are you guys running. I have the stock one seems really small compared to my fuel lines. Seems like the in and out lets are 1/4 inch.

Running 454/ with 177 Weiands.

Steve

Just the stock one, I just change it every time I change the oils, for $5 I don't know why you wouldn't, it's also super easy to change on mine.

Stock one is 3/8 in/out. Merc ran them with no problems on the 525sc. Above that HP level it propbably needs upgrading.

duplicate post