Dave,

I'll check that this weekend. Where would you start at looking for a vacuum leak?

Thanks
Dock

I'll take a close look at that also.

Thanks

switch arrestors between the motors. There is a small filter intake inside the plenium that will get carboned up also. I had a 525 last year that was making a whistle noise and it turned out to be the intake gasket. I changed the iac and all gaskets before finding it.

I have a pair of 500 EFIs' in my current boat and I also hear a rather loud air"sucking" sound at idle, sometimes, especially upon cold start up, or when backing off from higher RPMs. My previous boat with a single 500 EFI did it also, especially if you would rev the engine and back it off quickly - was told it was the IAC system. Engine also sounded really loud when it was cold, ie, just started for the first time that day. The sound would gradually go away once the engine started to warm up. I now live in North Carolina, previously in Ohio, and have noticed that down here in NC, that the IAC system seems to work harder/longer than when I lived up north (if that makes any sense). Having 2 of them side by side, now, makes the intensity of the noise even more noticable, but it does gradually quiet down as the engines warm up, or if you blip the throttle, it will kick in until the idle speed goes back down to 750ish.

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Never tired starting fluid, but should work, just make sure you have a pin point nozzle to direct your spray otherwise the intake will take over and defeat your efforts.

be cautious around hot exhaust, tends to ignite.

There are several reasons to NEVER use "starting fluid" in situations like that. DEATH is the biggest one. Fire is second and engine damage is third. The fumes from a can of ether can become so dense in the engine compartment that you will pass out, fall in and possibly die. The fumes can be easily ignited by a bad spark plug, wire, dist. cap etc and you burn or die. The boat can burn. If you find a big enough vacum leak with ether, you could blow a piston apart.

A nice, safe way is to use a (non flammable) brake cleaner to do the same job. The exhaust will start to smoke and smell like hell if you pull brake cleaner thru the combustion chamber. Its non greasy, doesn't leave a mess and wont blow your arse up.

for 25yrs been using carb cleaner to find vacum leaks, start mtrs, and diagnos fuel problems

its a little less combustable then ether and works great

I had that same problem--in the end it turned out to be failure of fuel pressure regulator. We changed everything and just happend to look at pressure regulator and it had corroded under paint and jammed partially open. As soon as we changed that unit the problem was solved.

The corrosion wasn't visible---found it by scrapping paint to find the part number and the things was all bubbled up. Was a good thing we found it when we did--if it had let go would have been some explosion.

Use WD-40...It wonk strip the paint or burn your boat down....It will pick-up the RPMs....

BOB-T !!....Where ya been ???....Whatcha got now ?