496, switched to thru prop exhaust, hard to start when warm
 

my gil captains's choice solenoids crapped out a few years back. They don't make the solenoids for the old Gil diverters anymore, so I wired them open. However wife and I have grown tired of the noise the past few season, so I went ahead and trashed the diverter pipes and changed it over to through prop exhaust full time.

A few times over the last two outings, the boat was hard to start back up after driving around for awhile. Boat has always started before with the thru hull exhaust.

When the drive was in the full down position, starting seemed difficult. When I had it trimmed up almost all the way due to shallow water concern, it fired right up. I don't like starting it or running it with the outdrive up due to the u-joint angle stress.

I am using the old style exhaust bellows. Maybe when the drive is up there is less backpressure???

496 as the Mercruiser OEM stock 8.1 with stock cool fuel system ? I understand the exhaust manifolds and risers were changed on your app

So what did you do with the check balls / check valves in the raw water cooling system ? with out them - heat soaked cooling water becomes very hot after engine shut down, then it drains back down in the cool fuel system boiling that fuel off. Hence vapor lock and no restart or very very hard restart of the engine. This is my guess to what is going on because of no check balls / check valves

If not I would scan the engine and look for sensor readings out of parameters / spec.

this is not a 496 fuel injected motor, no computer, no check balls, etc. The starting issue began when I switched the exhaust over. Yesterday I removed the exhaust bellows and went back out, boat restarted easily everytime, like it always has. I guess I will order the updated exhaust tube.

Not starting a bash or fight here but 90% of the time anyone says 496 this means 8.1 fuel injected engine in the marine world.

Call Mercruiser, Volvo, Indmar, PCM, Raylar and so on and ask them questions about your 496 without any other info to exactly what your app is and 100 % of those OEM Marine engine manu's are going to think you have 8.1 fuel injected marine engine.

for proper help you need to post what in the world you have exactly so people do not have guess. Just saying.

And also most likely its a Mercruiser ? But this info was left out to. just saying

Anyways good luck with it.

yes you are right I should have said 496 with carb engine, and been more specific. I have never had a boat that has fuel injection, computers, etc. so I forget that many folks have newer more sophisticated engines. I guess my punishment for trying to avoid fuel injections/computers etc is a carbed engine that doesn't like to start when it is 100 degrees outside sometimes, although I think I have alleviated the issue

All my big block boats came with exhaust tubes, not a bellows. Really no need to order a tube. Just cut the bellows and make your own "tube". I've seen this done on a lot of boats over the years.

I have a new unused tube, pay shipping and its yours if you want it. PM me

thanks for the offer, already picked one up on ebay for $20

installed tube, no restart issues all weekend. I guess the bellows is too restrictive for a BB engine when its 100+ outside.