[Sdancer9040]

Hi everyone,

i am looking to purchase a 340 with these engines on and wanted to know your feedback.
I read that many of these engines had to be replaced by mercruiser because of water ingestion, I even read of owners that went through3 sets of engine replacements in less than 4 years with these engines.

Anybody really familiar with these ? i would love to know more about them, since to me it will be a huge investment and don't want to mess it up from the beginning.

again thanks for your support

Regards.

 

[Boater_Rob]

I had a '99 34 with 380 hp Horizons under contact last fall. It had the old style "log" mufflers. Both engines had low and widely divergent compression readings. The worst compressions were on the cylinders directly below the risers.

The newer style exhaust consisted of a water lift type muffler - it looks like a 5 gal bucket directly behind the engine with 45 degree inlet tubes on each side and two discharge tubes coming out the top. I believe this solved the problem for the most part... the more experienced CSR folks can correct me if this is not the case.

BTW, if you haven't already, be sure to check out MasterFab's blog: http://searay340restoration.blogspot.com

He completely redid an '02 340. I had a chance to see hang out with him a couple weeks ago and see his boat - it's absolutely beautiful. He's the man for 340 questions!

 

[Sdancer9040]

I had a '99 34 with 380 hp Horizons under contact last fall. It had the old style "log" mufflers. Both engines had low and widely divergent compression readings. The worst compressions were on the cylinders directly below the risers.

The newer style exhaust consisted of a water lift type muffler - it looks like a 5 gal bucket directly behind the engine with 45 degree inlet tubes on each side and two discharge tubes coming out the top. I believe this solved the problem for the most part... the more experienced CSR folks can correct me if this is not the case.

BTW, if you haven't already, be sure to check out MasterFab's blog: http://searay340restoration.blogspot.com

He completely redid an '02 340. I had a chance to see hang out with him a couple weeks ago and see his boat - it's absolutely beautiful. He's the man for 340 questions!

Bob,

thanks for your information,it looks like i should do a compression test before spending any money on a full survey. thanks again and good luck on your new contract. sent you a pm

 

[Sdancer9040]

Hi everyone,

i am looking to purchase a 340 with these engines on and wanted to know your feedback.
I read that many of these engines had to be replaced by mercruiser because of water ingestion, I even read of owners that went through3 sets of engine replacements in less than 4 years with these engines.

Anybody really familiar with these ? i would love to know more about them, since to me it will be a huge investment and don't want to mess it up from the beginning.

again thanks for your support

Regards.

Any other info on these engines?

i am about to put a deposit on a 2000 340 with this set up

thanks

 

[mquiet]

The 8.1 horizons needed an exhaust lift as you have notes due to water ingestion. If it was done and caught then these engines and boat are good to go. My understanding was it was limited to the Horizon models and not the standard 7.4's with 310hp. I do have an exhaust riser on mine so that the exhaust is not as horizontal and increases the downward flow of water. If you are looking at a 13-14 year old boat, and the merc tech clears the engines you should be good to go.


Sent from my iPhone using Tapatalk

 

[Rudi K]

If it has the log style mufflers I would stay away from the boat, you want the water lift type that are round like a bucket. Make sure you do a compression test and check the spark plugs and make sure they all look the same. Last spring when I bought my 2000 340 with Horizons, we found two spark plugs the looked brand new and the other 7 looked the same. It had 2 dead injectors on each engine #6. The boat turned all most full RPM on sea trial,but it had that funny rumble sound at idle in gear. We installed two new injectors and the boat ran perfect and the rumble was gone at idle in gear. You will have some moisture in front of the windscreen most likely no big deal just remove and re caulk wind screen.

If you have any other questions let me know.



Rudi

 

[Sdancer9040]

If it has the log style mufflers I would stay away from the boat, you want the water lift type that are round like a bucket. Make sure you do a compression test and check the spark plugs and make sure they all look the same. Last spring when I bought my 2000 340 with Horizons, we found two spark plugs the looked brand new and the other 7 looked the same. It had 2 dead injectors on each engine #6. The boat turned all most full RPM on sea trial,but it had that funny rumble sound at idle in gear. We installed two new injectors and the boat ran perfect and the rumble was gone at idle in gear. You will have some moisture in front of the windscreen most likely no big deal just remove and re caulk wind screen.

If you have any other questions let me know.



Rudi

the boat that i am looking at does have the bucket like mufflers...

 

[Sdancer9040]

the boat that i am looking at does have the bucket like mufflers...

My bad, I looked at the boat for second time and it does have the "logs"mufflers.
Engines have 400 hs , I guess I will do compression test and take it from there.
i need to find out the cost of modifying exhaust. Any idea?

 

[Sdancer9040]

My bad, I looked at the boat for second time and it does have the "logs"mufflers.
Engines have 400 hs , I guess I will do compression test and take it from there.
i need to find out the cost of modifying exhaust. Any idea?

This boat is not going to work, deal is off, i am still looking for the right boat w horizons 454 or 8.1 v drives, thanks everyone for your support.

 

[dpmulvey]

This boat is not going to work, deal is off, i am still looking for the right boat w horizons 454 or 8.1 v drives, thanks everyone for your support.

I was unaware the 8.1's had the issue. Saint Max did and it was in 7.4's. The engines were replaced with 6.2 Horizons and it runs just fine. A friend has a 360 with 8.1's and burns roughly 36 GPH at cruise. Another friend with a 340 burns 32. I burn 22 GPH at the same speed albeit at a slightly higher RPM but hauling around 400+ less pounds of engine and transmission.

As to the exhaust, the waterlifts are nice for extra room, but not a necessity. My Horizons have a space between the mainfold and the elbow that eliminates the problem. That's not from me, that's from my mech w/ 24 years in the business.

Good luck in your search.

 

[Sdancer9040]

I was unaware the 8.1's had the issue. Saint Max did and it was in 7.4's. The engines were replaced with 6.2 Horizons and it runs just fine. A friend has a 360 with 8.1's and burns roughly 36 GPH at cruise. Another friend with a 340 burns 32. I burn 22 GPH at the same speed albeit at a slightly higher RPM but hauling around 400+ less pounds of engine and transmission.

As to the exhaust, the waterlifts are nice for extra room, but not a necessity. My Horizons have a space between the mainfold and the elbow that eliminates the problem. That's not from me, that's from my mech w/ 24 years in the business.

Good luck in your search.

that is good to know and it makes sense that if the elevation of the elbow is high enough, there shouldn't be any problem i guess...