BF225 IAB mounting screws seized..... ideas?

Went to change my high pressure fuel filter today but the two screws holding the IAB diaphragm in place are seized. They were not removed last year but 'should' have come off the year before but, given the other stuff I've found since starting to do my own maintenance, this may not have been done

So far I've just sprayed WD40 liberally on them and before I go too far has anyone got any suggestions to help get them out?

Anyone replaced them with bolts?

Try PB Blaster. Soak bolts as best as possible. Slot in the Phillips head screw driver and tap, tap, tap, and tap some more. If that doesn't work, then you will need to remove the IAB as follows, assuming that you have the cowling either removed, or loosen up and peeled back....

• Remove the 10 mm bolts at each end of the frame piece on the back of the engine that the cowlings bolt to. This will allow you to pull down on that frame piece an inch or so in order get to the bottom two bolts of the IAB.

• Remove the ten 8mm bolts holding the IAB in place

• Grab the loose IAB in one hand and pull back on the cowling frame with the other hand to allow you to pull the IAB and diaphragm up and out.

• Then remove the two Phillips head screws holding the diaphragm in place, using more PB Blaster, or and impact driver. Be careful not to damage the baffles inside the IAB.

Replace the Phillips head screws with hex-head bolts, or as someone else suggested, with Allen-head bolts. Put anti-seize grease on the threads.

Cool.... sounds like a plan.

Not sure I can get PB Blaster in the UK but will check, otherwise I'll let it soak for a few days and try again. Last resort will be to remove the IAB - does it have a gasket around it?

..... ahh, found the section in the shop manual - no gasket. Found some PB Blaster on eBay so will give that a go first.

Right - If I recall correctly, it did not have a gasket.

Try flooding the bolts with plus gas. Leave for 6hrs the re apply for another 6. Fingers crossed.

How did you make out? Sometimes, just to break the corrosion you can tighten just a a bit and it’s enough. Am inpact screw driver can help too. Of you can’t get them out, left handed drill bit to the head. Once the drill bites it will usually unscrew the screw. Good luck!

Away from the boat for a few days but have left the screws soaking on PB blaster. I suspect I'm going to have to remove the IAB completely.
I do have a left handed drill bit so may have to try that.

If you remove the IAB, you can get to those screws loose with an impact driver - the kind you hit with a hammer. That assumes that the Phillips heads are no too messed up.

A screwdriver with a 2 foot long shaft or longer with the proper sized head works wonders. I cannot figure out why the length of the shaft makes the screwdriver remove frozen screws so much better but it does. Obviously the intake cover plate will have to be removed to be able to access those screws with a screw driver that long. Place the intake cover plate "upside down" where the IAB screws are facing straight up. The plate has to be held there firmly with no play. I suggest putting it between two cinder blocks with a towel for abrasion protection. Push the blocks together tight enough to hold the plate and stand over the plate with your feet on the outside side of the cinder blocks holding pressure against them. That should stabilize the plate enough. Make sure the screw driver head fits the screws PERFECTLY. Standing over the plate engage the screws with the screwdriver and place fairly heavy pressure down on the screw as you turn to loosen. You'll need that pressure to prevent the screwdriver from jumping out of the screw head.

I've broken screws free with this method that were so tight they made a "snap" sound when they started to turn. This is where quality screwdrivers matter.

Again - just be super careful about not messing up those baffles inside the IAB. If you bend or break one, it's a new IAB - $340 plus.

I got mine out using a 3/8 impact driver with an extension. Obviously, I did not hit the crap out of it, but I was able to get it free. When I get ready to put everything back together, anti-seize will be my best friend!

Well I've drawn a blank on getting these damn screws out. They've soaked in PB Blaster for well over a week, I've tried tapping with the hammer and a long screwdriver. I've taken the IAB off to get better access to them but the heads of the screws are now chewed up - tried cutting a slot for a big flat head screwdriver and an impact driver but that's not working either.

So I've temporarily resigned myself to the fact that I'll be removing the IAB every time I want to change the filter..... could be worse!

At least the IAB is nice and clean now

There is always a way to get them out. At this point I would try two other things...

Get a reverse bit smaller than the screw and drill straight down into the center of the screw, with your drill in reverse. Most times, that alone will extract the screw. If not, then get a small "easy out" AKA a Spiral Fluted Screw Extractor, which will grip the inside of the hole you drilled and allows you to turn out the screw.

Metal chicken, purchase a few left handed drill bits and a center punch. Take the center punch and punch a point in the middle of the head. It needs to be centerted. Start with a smaller left handed drill bit to make a pilot hole. Take your time and get it started correctly. Move to the larger left handed drill bit. The left handed drilling action should make the screw turn out. If not you have a hole to use your ez out on.

As a couple mentioned, the impact screwdriver is really good.

I never knew these existed, but think anyone who has a saltwater run anything should definitely have one in their toolbox.

My IAB screws were destined for a certain dreaded drill out and then heard about this day saving tool.
Soaked them in PB and made my day when I saw the head move after a few hammer hits.