Is Something Wrong with my engine?

General Boats and Motors
1

I also posted this at CarolinaSkiffOwner.com
I have a 2004 1980dlx with a Yamaha 90 2S looks like this:

I had a new powerhead installed last summer and did not run it much after the replacement. Before I lost a cylinder, I remember it being very strong and being able to put 6 of us in the boat and it would plane off OK. I added the weights and it comes to about 1000 lbs. Since then I have installed the 2nd battery (little more weight), and replaced the powerhead and here is what it is doing:

With 2 people it is OK but seems slower than I remember.
With 3 it planes OK but seems sluggish. WOT rpm trimmed up is about 5000
With 4 it struggles to get on plane, takes about 20-30 secs.
With 5, forget it. Will not get on plane or turn more than 3600 rpm.

I have 3/8 fuel line to the external filter and 5/16 to engine. Does it matter? Same setup as before. I have had the carbs cleaned twice this year and just replaced my plastic gas tank. The shop that replaced the powerhead serviced it this spring and said all was well. A different mechanic cleaned the carbs later and said it was running fine. I have not pulled the prop to check the pitch but it is the same stainless black prop I have always run. The boat is rated for a 115 max hp.

What do y’all think. How many people can you carry?

Slow A$$ Carolina Skiff Doug

Carolina Skiff Doug
1980DLX Carolina Skiff

2

I’ve always heard that an engine runs it’s best right before it goes kaplunk! I don’t have any idea about what might be wrong but it seems like a new power head ought to have as much power as an old one.

Cape Horn 24OS
twin 150 Optimax

I don’t want to be rich,
I just want 1 dollar more than I can spend!

3

Your not getting full HP. Local shop in NC has a Dyno, see if you can find one nearby or find a new tech.

4

Check the compression on the new powerhead

5

you should definately be doing better than that
I have a 17 skiff with a 50, and with 4 people, it will plane off no problem

www.teamcharlestonmarine.com
www.joinrfa.org

6

What Chris said. I have a 17DLX with 70 hp and it will plane with 5 full grown men and shrimping supplies on board. Would consider a compression check.

“Go Tech GO”

7

Take it to Charleston Marine. They will tell you what the problem is, if there is one, and fix it too.
Mr Hardware