Mercruiser 4.3 Manifolds/Riser

[krakatoa]

Hello Guys!
Dealing in a Mercruiser 4.3 that needs Manifolds / Riser, one of the manifolds was clogged by salt water "as owner said". Just nned If someone point me in the correct direction where to start looking for both parts. I only have by now the Serial Number M08374, Any idea where to download the service manual for this engine? I know about boatinfo.com but there is a lot of manuals for Merc and not sure wich one is the one needed. Alpha One

Thanks

 

[alldodge]

Here is the two piece ones, if you had the one piece IMO they should be replaced.
http://www.mercruiserparts.com/bam/subassembly/31480/2694/130

 

[krakatoa]

Here is the picture of the label founded close to the starter
and the engine too. Regarding Manifolds and Risers those parts comes in kits or just can easy exchanges gaskets?

​

 

[JonBrown]

Im not a Huge Sea Ray fan, but that is a nice boat! I had a customer with the same problem last week and he went on Craigslist and bought a like new set for 200.00 I didn't here you complaining about the price but they were local and easy to get . It is worth a check. Dont forget to order the gasket kit/flappers. Hope this helps.

 

[Scott Danforth]

most likely both manifolds and risers need replacing. the clogging is most likely the iron flaking off on the inside from rust.

 

[krakatoa]

In top of the engine I found the following number: GM12552422 not sure what this one means. Did a search on CL in my area and there is a ton of marine parts sale store where I can start from. If anyone have a link to a download Service Manual please share. I did OB before but not in/out. The engine has been out for over two years, it cranks nicely but doesnt start.

 

[krakatoa]

most likely both manifolds and risers need replacing. the clogging is most likely the iron flaking off on the inside from rust.

well if that is the case looks like good news to me cause I thought it was clogged because the salt or poor flushing. Will stop by place today to double check there is no water on oil. Boat has been storage for 2 years and engine was started last year. Yesterday we try to startup but was not succesfull but it cranks pretty nice and sounds with power.

 

[Scott Danforth]

you found the casting part number of the intake manifold on top of the engine. the serial number is on a tag on a plate that says mercruiser (or volvo, etc.) that is riveted onto the block above the starter mounting boss on the Right / Starboard side of the motor. it is also printed on the paper tag you see on the intake spark arrestor.

Exhaust manifolds and risers only last 5 years in salt (a light bit more with flushing) regardless if they are used every day or used once a year. They are a maintenance item, that if not maintained start to leak and take out the motor.

if this was a freshwater boat only, the cast iron manifolds would last 40+ years (I have not owned an older freshwater only boat yet)

 

[krakatoa]

you found the casting part number of the intake manifold on top of the engine. the serial number is on a tag on a plate that says mercruiser (or volvo, etc.) that is riveted onto the block above the starter mounting boss on the Right / Starboard side of the motor. it is also printed on the paper tag you see on the intake spark arrestor.

Exhaust manifolds and risers only last 5 years in salt (a light bit more with flushing) regardless if they are used every day or used once a year. They are a maintenance item, that if not maintained start to leak and take out the motor.

if this was a freshwater boat only, the cast iron manifolds would last 40+ years (I have not owned an older freshwater only boat yet)

Yes I found the SN in top of the starter, its pictured on first set of pictures. I will ask anyway about the salt/freshwater to owner. Its looks like its a common thing the replacement of the Manifold/Raiser.

 

[Scott Danforth]

Its looks like its a common thing the replacement of the Manifold/Raiser.

expect every 5 years in salt, be delighted if they still pass inspection and you can get another year or two.

 

[denhajm]

I just ordered a set yesterday for my '90 SeaRay from this place:http://shop.nuwavemarine.com/categor...inder-exhaust/ They had the best price going for OEM stuff after searching online for weeks. Once you nail down your engine s/n (which is normally on those stickers on your air filter--but yours look unreadable) you should be able to zero in on what you need. To me, it looks like you need to verify if you have 7 degree or 14 degree riser angles. Good luck.