Yes, I just hosed mine down this morning looking for a leak. Use carb cleaner.

i would check sparkplug wires & cap are not broken before you start to spray brakeclean all over engine.Another way to check is to put a vacuum gauge on a intake port to see wat kind of vacuum you have.

if the gauge shows low vacuum, the carb cleaner trick will work to see if it is the cam causing low vacuum or if you have a leak. i agree tho, make sure you dont have any open sprak before hosing it with flammable liquid

your engine has same symptoms for IAC i had to replace. replace it. no idle and die on pull throttle back, good sign of it.

Replace it... it's a 10 minute job and you know that the new part should work. If this doesn't fix the problem, then go from there but at least you ruled it out. Hope you got the part for under $30 at an auto parts store instead of $100 for the Mercruiser part.

Thanks all, I'm going to replace it as a first step, although I can't find one cheaper that $50 at any local auto stores here ! Then work forward from there.

I'm hoping that the fact it happened 'instantly' indicates a part failure somewhere rather than a whole mess of 'worn out' problems.

MASTER PRO PART #21755 or 2-IAC2

I think that O'Reilly and a few other stores carry this brand. $26 vs. the merc part #805224A1 which is nearly $100

I appreciate that. The O'Reilly web site lists a 21755 by BDW at $53, same for NAPA, but a few $$ more. I've found that x-ref for the Merc part number.

The 2IAC2 is $26, any difference I wonder ? The only apparent one from the web site is that the 2IAC2 seems to have a brass pintle, the 21755 seems to be something different, but similar in appearance, (grey metal), to the Merc original.

I replaced both of mine with the $26 ones and the engines idle great. No problems.