Repower issues

[Dmark1]

Hello, I replaced my 454 7.4 Mercruiser with the replacement engine that was authorized by Mercury, the 383 stroker engine, I’ve only had issues with this engine and it’s going on the replacement of the second 383 engine, is anyone else experiencing this issue?
Thanks

[mmwjr]

Originally Posted by Dmark1

Hello, I replaced my 454 7.4 Mercruiser with the replacement engine that was authorized by Mercury, the 383 stroker engine, I’ve only had issues with this engine and it’s going on the replacement of the second 383 engine, is anyone else experiencing this issue?
Thanks

I’ve not heard of any issues with the 383. What problems are you experiencing?

[Dmark1]

Originally Posted by mmwjr

I’ve not heard of any issues with the 383. What problems are you experiencing?

Boat is under powered, plugs are getting fowled

[mmwjr]

Originally Posted by Dmark1

Boat is under powered, plugs are getting fowled

What size boat, year, and weight?

Does it feel underpowered with fresh plugs? When you remove the plugs are they fowled with wet gas or soot?

[Dmark1]

Originally Posted by mmwjr

What size boat, year, and weight?

Does it feel underpowered with fresh plugs? When you remove the plugs are they fowled with wet gas or soot?

It’s a 29’scr singe engine 2001, 8000- 10,000 depending if it’s full gas and water, it’s black soot, cylinder 5 isn’t firing

[mmwjr]

Originally Posted by Dmark1

It’s a 29’scr singe engine 2001, 8000- 10,000 depending if it’s full gas and water, it’s black soot, cylinder 5 isn’t firing

Thanks. Even with the original 7.4 that boat wasn’t a power house. The 383 can produce a lot of power but not the low rpm torque that a big block can. The problem is Mercruiser no long offers a big block since GM stopped producing them. However an aftermarket 496 would have been my choice.

Sounds like you got a bad engine if a cylinder isn’t firing. I would wait to see how the replacement performs.

[Dmark1]

Originally Posted by mmwjr

Thanks. Even with the original 7.4 that boat wasn’t a power house. The 383 can produce a lot of power but not the low rpm torque that a big block can. The problem is Mercruiser no long offers a big block since GM stopped producing them. However an aftermarket 496 would have been my choice.

Sounds like you got a bad engine if a cylinder isn’t firing. I would wait to see how the replacement performs.

I’m trying to negotiate for the 8.1, I’m willing to pay the difference if they pay for the labor to install, my shipyard is working with mercury, wish me luck 🍀

[mmwjr]

Originally Posted by Dmark1

I’m trying to negotiate for the 8.1, I’m willing to pay the difference if they pay for the labor to install, my shipyard is working with mercury, wish me luck 🍀

Best wishes.

[shrew]

Mercruiser still sells the 8.2 (502) big block. There are plenty of remanned 496 (8.1) around from places like Michigan Motors.

383 Stroker is a small block with sufficient HP, but not a ton of torque. The 2800 and 2900 were right on the bleeding edge for a single big block IMHO. I had a 1999 2800 (same class as the later 2900), and I had to move the cooler and the honda genny and the roll up dinghy down in the cabin companionway to get up on plane efficiently. If I had guests, I had to move them forward too.

[Dmark1]

Originally Posted by shrew

Mercruiser still sells the 8.2 (502) big block. There are plenty of remanned 496 (8.1) around from places like Michigan Motors.

383 Stroker is a small block with sufficient HP, but not a ton of torque. The 2800 and 2900 were right on the bleeding edge for a single big block IMHO. I had a 1999 2800 (same class as the later 2900), and I had to move the cooler and the honda genny and the roll up dinghy down in the cabin companionway to get up on plane efficiently. If I had guests, I had to move them forward too.

Yes, small block doesn’t have the torque of the 7.4, I’m dealing with Mercury on this issue currently, I’m trying to get owners of similar or same situation to come forward, thanks for your reply.

[Dmark1]

[QUOTE=Dmark1;75535]I’m trying to negotiate for the 8.1, I’m willing to pay the difference if they pay for the labor to install, my shipyard is working with mercury, wish me luck 🍀[/QUOTE

Great news, Mercury is going to replace the 383 with the 8.2, I’m very happy 😊 ]

[mmwjr]

[QUOTE=Dmark1;75566]

Originally Posted by Dmark1

I’m trying to negotiate for the 8.1, I’m willing to pay the difference if they pay for the labor to install, my shipyard is working with mercury, wish me luck 🍀[/QUOTE

Great news, Mercury is going to replace the 383 with the 8.2, I’m very happy 😊 ]

Excellent!