I have the slightest of surges on my port 2002 496 Mag HO. When I hooked it up to my Diacom software, the IAC percentage seemed to be below 40% but the TPS at idle is showing 0.12% and surges to 0.25% and about 0.55V at idle. Could this be the TPS starting to show some signs of wear and...
I have mechanical throttles on my 496 mag ho. Can someone tell me where the IAC is mounted? It does not appear that it is on the throttle body and the air hose appears to run to the back of the engine.
Is there actually a diagram somewhere that actually shows locations of the different...
I'm in the process of ordering the Diacom software for my lap top to help me diagnose a TPS / IAC issue on my port engine. One of the things that I've read is to check the timing (with a timing light) and not the PC/Software. That being said, how do you adjust the timing on these computer...
I'm about to reinstall my 7.4L (now a 496 stroker)back into my boat. I'm changing all of the engine mounts. According to my research, the flywheel housing has the old style mounts utilizing the double wound lock ring. When buying the new mounts, do I go with the new style (deletion of lock...
I'm about to stab my new 496 stroker into my boat. I'm pretty sure that going from 300 hp to 550 hp will require me to prop up. Currently have a 21 pitch that was right on the money for my original 7.4L which redlined at 4600 RPM's. My new 496 stroker should red line around 5600 with the...
I am building a Mark IV 454 (496 stroker) engine to replace my 1993 7.4L which is a Gen V. This is the new bbc marine oil pan I bought which indicates a direct replacement for Mercruiser part no. 93477. What dipstick tube/stick do I use for this? The oil pan also has 3/8" NPT ports with plugs...
Does someone know of a stainless steel replacement for the big bulky thermostat housing part no. 16413A 3? There seems to be a stainless steel equivalent but it doesn't seem to have enough outlets. It seems to be missing two. Is this the right one or is there something else out there that can...
I believe I've asked this before, when changing out engines, I've read you should remove the lag bolted mounts. I am doing this due to the fact that the adjustable mounts are completely rusted out anyways. When putting the mounts back on the stringer however, do you just use longer lag bolts...
I didn't want to hijack someone else's post but I have a similar problem to a recent post. My trim switch on the throttle will trim down but not up. However the trailer switch still brings the outdrive up. Is it my switch on the handle or is it the limit switch? A detailed test procedure...
Going from a 300 HP 454 engine to a 500-550 hp 496 engine. Currently have a sstl 21P x 14.8" prop. Any ideas on how much I will need to prop up or where to start? Engine max RPM to be around 5600 RPMs. Boat is a '93 Crownline 225 CCR and weighs about 3800 to 4000 lbs. (guessing). Outdrive...
I currently have a 1993 Crownline, 225 CCR with a Gen V 7.4L Bravo 1. It has met it's doom. I have a new custom built 550 HP 496 stroker to replace the old girl that utilized a Mark IV block in lieu of the Gen V. With that being said, I want to use the 1988-1991 Mark IV sea water pump WITHOUT...
I've noticed that a new exhaust valve from Mercruiser is approximately $65-$90 depending on where you buy them. Are these stock exhaust valves the good Inconel ones or are they just plain Jane high mark-up stainless steel. If they're just stainless steel, will there be any problem just...
I currently have a 300 hp 7.4L bravo 1 with a 21P prop. My new 496 stroker engine will be right around 400 hp. Is there a calculation that I can use to guess the new prop size. My rpm range is going to go from a maximum of 4600 to approximately 5500 as well. Boat weight is approximately 4000...
I am in the process of putting a new 489 stroker in my old Crownline to get a few more years out of it. The existing mounts in the front have a lot of corrosion on them so I am replacing them. What is the normal process, do you refill the existing lag holes with fiberglass or possibly use...
1st Question: I pulled the starboard exhaust elbow off to visually inspect my manifolds for corrosion. They seem to look fine. (chasing an engine temp. heat up at idle) Since the exhaust system looks good, I bought a new gasket to put back between the manifold and the elbow. This gasket has...
