bkdlays
Cadet
- Joined
- Jul 20, 2008
- Messages
- 18
Hey guys. Im new here. My name is Jim and I just got a 25' Larson Senza.
It has a 7.4l 454 with a Mercruiser Bravo I Drive (I believe)
Scratch that- It is a 7.5l 460 with a Cobra Drive I have been told below!
I have quite a few questions about the boat. I have already learned quite a bit just reading on these forums.
I do not have a vast boating background, but I am very skilled in electrical diagnostic and general automotive. I hope to be able to help others with their troubleshooting.
I guess Ill just make a list and see what people have to think. If this is not proper please let me know and I will break up the post.
My first problem is the boat leans to the left. Is there something that can be adjusted? It is noticeable at higher speeds when the boat is on plane and when turning left its particularity bad. The bottom of the skeg is broken off, but its a small piece. Could this cause this? I didn't pull the plug on the boat last time it was out, but i cannot see how this would cause it either?
The motor runs ok when cold, but once its hot its temperamental about restarting. It takes quote a bit and then sometimes it will stall out when you first put it into gear. Today it would simply not restart when hot. It acted like it was flooded out. Once it cooled it started and ran fine.
I believe the shift cable is stretched or bent. Previously the boat would only go forward no matter what position the throttle was (forward or reverse) I tested the cutoff switch and it seems to be working.. just not at the right time always. We adjusted and lubed the cable and get ok performance out of it, but its not right. I think changing the cable will help some of my problems.
The carb looks brand new. I belive the boat is running rich though. The exhaust smells very rich. When putting around at slow speed it backfires once in a while. It feels loaded up and you need to open it up to clear it, it seems. For a 7.4 I would expect better throttle response from this boat.
The ignition system seems antiquated. My mechanic tried to check the timing, but he wasn't sure if it had an ignition advance. I read about the thunderbird ignition I believe. It was said to have a wire on the carb, like this.
Wouldn't it make sense to simply upgrade it to a new HEI system?
That should cover me for now. Thanks for reading this far!
It has a 7.4l 454 with a Mercruiser Bravo I Drive (I believe)
Scratch that- It is a 7.5l 460 with a Cobra Drive I have been told below!

I have quite a few questions about the boat. I have already learned quite a bit just reading on these forums.
I do not have a vast boating background, but I am very skilled in electrical diagnostic and general automotive. I hope to be able to help others with their troubleshooting.
I guess Ill just make a list and see what people have to think. If this is not proper please let me know and I will break up the post.
My first problem is the boat leans to the left. Is there something that can be adjusted? It is noticeable at higher speeds when the boat is on plane and when turning left its particularity bad. The bottom of the skeg is broken off, but its a small piece. Could this cause this? I didn't pull the plug on the boat last time it was out, but i cannot see how this would cause it either?
The motor runs ok when cold, but once its hot its temperamental about restarting. It takes quote a bit and then sometimes it will stall out when you first put it into gear. Today it would simply not restart when hot. It acted like it was flooded out. Once it cooled it started and ran fine.
I believe the shift cable is stretched or bent. Previously the boat would only go forward no matter what position the throttle was (forward or reverse) I tested the cutoff switch and it seems to be working.. just not at the right time always. We adjusted and lubed the cable and get ok performance out of it, but its not right. I think changing the cable will help some of my problems.
The carb looks brand new. I belive the boat is running rich though. The exhaust smells very rich. When putting around at slow speed it backfires once in a while. It feels loaded up and you need to open it up to clear it, it seems. For a 7.4 I would expect better throttle response from this boat.
The ignition system seems antiquated. My mechanic tried to check the timing, but he wasn't sure if it had an ignition advance. I read about the thunderbird ignition I believe. It was said to have a wire on the carb, like this.
Wouldn't it make sense to simply upgrade it to a new HEI system?

That should cover me for now. Thanks for reading this far!
Last edited: