Smarty pants, I really could use your help! 350 Mag trouble SOLVED?? MAJOR UPDATE

Black_Diamond

Great work. Sad you had to do it yourself. Glad Al helped you too, he is beyond nice to offer and help. He did that for me too. 

Keep us posted!  

GMSLITHO

Pros ......

you mean no one ever looked at the risers 

Wildboating

Black_Diamond said:

Great work. Sad you had to do it yourself. Glad Al helped you too, he is beyond nice to offer and help. He did that for me too. 

Keep us posted!  

Al was a breath of fresh air when talking to a pro. Sadly, he never received any of the thousands I ended up spending with others yet he would occasionally call and suggest some ideas.  

Wildboating

I’m not getting excited yet, but it all seems to add up in my head.  These were clear issues that certainly could and would cause damage to the manifolds.  Sea test coming up soon.  Stay tuned. 

rasbury

So, I'm curious...and I don't know a lot about the riser design ....so how exactly did it fail? Is the riser just a passage way for exhaust and water? Is yours closed cooling or raw? I have my risers off but really have not looked at them...there are check valves in there😐? Did the passage ways between the exhaust and water fail?

Wildboating

The riser should actually have a cooling passage that allows water to circulate around the riser.  I suppose low flow over time allowed excessive corrosion to develop and ultimately close off the cooling passage.  The riser may be possibly cracked from the water jacket to the exhaust passage as well but it has not been confirmed. 

My boat is raw water cooled, the ball valves thread into the bottom of the exhaust manifold. 

Dream_Inn

Well, it sure sounds like you have figured it yourself by getting in there and getting a complete understanding!  That is just awesome!!!!  I do believe you have figured it and really wrote it up well here.  I can't believe over the years I have read all 32 pages and time again.  This is an absolute amazing find!!  Congratulations!!

Stodge

Handymans342 said:

This could easily be turned into a book!

I was thinking mini-series.  But the big question is who would play Al?  

reneechris14

Sound like water flow maybe solved. Good luck with sea trail. Video of throttles and tachs.

212rowboat

you've taught me a lesson... "always check flow before digging in"... 

great job, sir!!!

dalek

Hope it's plain sailing for you from now on.

Liberty44140

Stodge said:

Handymans342 said:

This could easily be turned into a book!

I was thinking mini-series.  But the big question is who would play Al?  

Obviously Bradley Cooper, no question. 

Dream_Inn

dalek said:

Hope it's plain sailing for you from now on.

I used to love House!

aero3113

Liberty44140 said:

Stodge said:

Handymans342 said:

This could easily be turned into a book!

I was thinking mini-series.  But the big question is who would play Al?  

Obviously Bradley Cooper, no question. 

How about Dwayne Johnson! (The Rock) LoL!!

Stodge

aero3113 said:

Liberty44140 said:

Stodge said:

Handymans342 said:

This could easily be turned into a book!

I was thinking mini-series.  But the big question is who would play Al?  

Obviously Bradley Cooper, no question. 

How about Dwayne Johnson! (The Rock) LoL!!

Need more explosions if he's in the movie.

Dude_Himself

Man, I really hope this is the end of this one. I can't believe with all the work that's been done no one checked the cooling system and exhaust properly - same lesson I learned this year: just do it yourself. It's worth it in the end.

BTW, is @rasbury on the water yet?

Handymans342

Nope

Wildboating

@Dude_Himself I’m too hope this is done.  Just nervous that I an unskilled mechanic solved what many many technicians and other well paid shops couldn’t.    At this point all I know is there was hardly any flow on that side, riser was bad and manifold was once again full of water.  I have sent the take off manifold to a shop to have a pressure plate built so I can test it for being broken this time.  I could not get water to leak out of it like the “pro” shop said they did every time. I certainly connected it the same way they did.  We will see. 

J3ff

I'd say Merc or the shops owe you 1000's in refunds. 

3300SCR

Just spent last several hours reading this thread. I hope your boat is running well, I recently purchased a boat with 2000 350 MAGs MPI.

i have a similar issue that has been around for years and I am fixing it myself. My port engine runs rich and bogs under load. Can’t get boat to plane, have changed almost all parts.

your story gives me hope, will get it running one day!

LaRea

For those of us who haven't read all 32 pages, and for newcomers to the forum, can somebody post a summary?  Maybe as a separate topic?