HyFive578

iTrader: (3)

I have a triple engine 47 Fountain with 525 EFI's. On my center motor, on the port header, front-most pipe ( ie: #1 cylinder), the outer jacket gets significantly hotter than the other three. When the boat is idling and even after some running, I can touch the outer jackets on 3,5,7 and they stay cool/warm whereas the #1 pipe gets REALLY hot and can't be touched. This does not happen on the back two motors (i.e. #1 cylinder jackets stay cool/warm) but they have swept back headers and the center has tall straight up pipes.

I am aware that the port side headers will usually be hotter than the starboard but the other jackets are staying cool. I pressure tested the header over the weekend (no leaks) and also back-flushed it a few times. There is no bluing or discoloration on the pipe at all, so I imagine it must be getting some water flow or it would be turning colors. Just not sure if this is expected or is there something wrong. Heat is the enemy with these headers, so I'm trying to head off a future problem.. any ideas??

Thanks, Neil

Baja Rooster

iTrader: (1)

I have no personal experience with the issue, but other members have posted the same problem with the issue being a plugged inlet.

HyFive578

iTrader: (3)

That has been my prime suspect because the tube that connects the jacket to the distribution rail is like 1" long and maybe 5/8" OD. I would have thought that pressurizing it to 60 PSI and then flushing with water would clear it though. My mechanic has suggested putting the restrictor bushings back in the tails. These were removed per the Mercury service bulletin. Thinks maybe too much water exiting too soon. Gonna try that next..

PARADOX

DON'T.
You should able to "touch" all pipes. You DO have some restriction. Try to "snake" it out with an "electric wire snake", (Used by electricians or like a very small plumbing snake" ) from the lower connecting water tube, and also back from the collecting box. or the No. 1 cyl, you might able to use and old windshield wiper metal blade, (thin and flexible) remove the blue little plug and try to go up in the tubes. Pressure alone will not get something out that might be stuck. Back wash will go to the least resistance and if something stuck (which is my assumption) it(water) will just go to other areas.

HyFive578

iTrader: (3)

Thanks, I thought the exact same thing. I tried getting in there with a wire hanger over the weekend but it's so tight to work in there; the little blue plug is right up against the oil filter lines. Gonna try it again tomorrow..

buck35

You might try a piece of 1/4 cable and Chuck it up in a cordless drill. Makes a great flail, just don't use too long a piece or will have an anaconda on your hands!

River Ratt

HyFive what did you end up doing here, how did you get it cleared? The exact same thing happened in my '29 Fever 525 last fall. It was right after I disinigrated the water pump impeller. I replaced the impeller started it and that front port tube got hot, so Im pretty sure there is a hunk of impeller in there. I've thought about cutting the 1" tubes so I can plug 3 and give the 1 hot one a good back flush but am hesitant since 1" cut in 2 doesn't give much meat for a hose and clamps to grab onto when I put them back together.

HyFive578

iTrader: (3)

I didn't do anything. I had the headers off this winter and I snaked some wire up there and there was no obstruction. We'll see what happens this season.

370ss500efi

last season my port header on port motor was hot at the e top collector. i wasnt getting enoigh water in from the drive. The plastic cone bushing where water hose connects to drive was collapsed, replaced and problem solved. I never imspected each header tube individually. I did have diminished water flow in the strainer so it seemed the right place to look