I just put my 23 CH on a 17' flats boat. The bottom is 44" wide, flat bottom boat. Weighs around 350 lbs hull only. Im only able to get 18-19 mph out of it by myself. I could hit 28-29 with it on a 1436 jon boat. I know that this boat is a lot bigger and heavier. Obviously I didn't think id be hitting 29 in this one but I thought it would be around 24-25. The back of the 1436 sat super low with this motor. This new boat sits and runs level with it. It is a 15" transom. My question is, are the BPS exhaust and carb kit worth the money? Do they help out the performance quite a bit or will I even notice it much?

1758 sure seems like a big boat for a 23hp. If it were me I wouldn't put much into souping up the 23 because sooner or later your going to wanna put a big block on there. You said those speeds were empty...have you ran it loaded yet?

The bottom is 44", not 58. My bad. But that was with me, fishing trim with trolling motor and fishing stuff. Not a hunting load. Haven't had a chance to run it with another person. I don't understand why a Gator trax 1438 that is all welded and heavier than this boat will run 6 mph faster with a 23. This boat isnt as heavy as a welded .125 boat. It doesn't sit low in the water or drag the ass end at all.

EDIT: That is the 1438 gator trax with huntdeck that makes it 15-6x38. Weighs around 450 lbs.

Must be an issue with set-up, or maybe the prop? I've got a 23 Dixie on a 1744 Phowler that weighs around 375. I can run 25 mph all day with two people and a light load.

Sent from my SM-N920R4 using Tapatalk

It has the stock 10" prop. It is not damaged. The weight is distributed pretty good too. The motor and the battery for it are in the back. Its a small lawn mower battery so its not heavy. Then the trolling motor and battery are up front on opposite sides. The fuel tank is under the front deck and centered. Just a cooler in the middle. The boat sits level side to side and front to back in the water. It turns 3700-3800 rpm running under load. It will turn 3900 sitting on the trailer out of the water. the boat only drafts 4" of water too. it doesnt sit low or anything. Today I ran it with one other person and averaged 16mph. Thats quite a bit slower than similar size and weight boats with a 23 that ive heard of. One guy around here has a CH23 on a 15' x 44" flats boat that weighs 300lbs and he runs 28 on a stock motor.

Are there any hooks in the hull?

No hook in the hull at all. It has a "v" to the front. The "v" stops after the first maybe 5 or 6 feet then it becomes completely flat. The transition from the "v" to flat is right where the bunk starts in this picture:

Here iscwhat the bottom of the transom looks like:

Also, I talked to the dealer I got the motor from today. He said try raising the motor up 1.5" or 2" from where it is mounted now. The boat has a 15" transom. Anyone ever mounted their Copperhead a little higher than 15"

Give it a shot. I think your problem is the design of the boat. They don't perform well when not on a true flat bottom boat or at least a ribbed Jon with a flat bottom


Sent from my iPhone using Tapatalk

The V-hull will hurt performance. Also check that prop, it should be an 11" diameter not 10".

Sent from my SM-N920R4 using Tapatalk

The prop is definitely a 10" diameter. The dealer I got it from said I could stop by and pick up a couple props and try them out. Is the CH23 stock prop supposed to be 11"?

Should be an 11x10

Sent from my SM-N920R4 using Tapatalk

IMO the mods are great if you do them right. But putting just a carb and exhaust on the motor wont give you much more. If your gonna do the mods I would go ahead and rework the heads, and do new cam and all. and make sure there done right.

I had/have a 23 copperhead (with the mikuni carb and bps exhaust) on a heavy 15/44 and it pushes the boat fine with no load but I would get about the same speeds your getting with a load. So like i said you wont get as much as you think unless you do heads, carb, exhaust, cam and all. I also ran my 23 on a 14/32 before I got my 15' boat.

But be forshure if you do the mods right because if you dont you will ruin your motor. I bought my 23 used with a carb and and exhaust and after about 15-20 hours the motor blew out so bad i couldnt even rebuild it. The rev limiter on it was broke and the jets in the carb were to lean. So if you do any mods make sure you find the right jets and make sure all is done right.

I have a 1744 with a 23 mud buddy HD has BPS cam did the heads myself decked .035 ss valves port/polished ect gutted exhaust mikuni carb. Did all the mods for about $1000 if you piece it together. I was running low 20s solo stock now it can run 26-27 @ approx 4500 rpms solo low 20s with 2 guys dog and gear. Saw a good 5 mph gain solo and 7-8 mph gain loaded compared to stock

I contacted Copperhead, they said the 10.25" prop stamped c-12 is what it is supposed to have. I talked to another small surface drive builder that my buddy is getting a motor from and that builder says he always puts an 11x10 prop on his 23hp builds. Im gonna try an 11x10 but CH said this one is correct.