Just picked up a new hull it is a 1848 flat riveted. Got away from the old mod v (thank god). Now time to set it up right. I need a new prop anyways, so what do you recommend? Motor is a 31 hp beavertail longtail.

Ran the boat over the weekend and its not planning out. Will pods help me out? running about 15 empty and 13 with 4 people. going to move the tank and battery up front and try again.

You should be able to plane fine with the 31 empty and with 4. That boat should be planed out long before you hit 15mph empty

that's my thoughts too. I sent a buddy out so I could watch from shore and boat was still squatting a lot. only him in the boat.

A 9x7 prop would probably shove that thing fine. You probably could even get something with more pitch or cup. I don't know if you can turn the wheel normally reserved for the 35 lt. May be a bit too much. Mb, gd, and backwater should all be able to hook you up with the right prop. I don't know anything about the beavertail props, but you could always call and ask them what they suggest.

What rpms are you turning? More speed will keep it from squatting so much. May be something wrong with the gov, could be a prop issue, or could be the carb needs a good cleaning, or a combination of any of the above.

thanks man. I will check all of that. Do you think pods are a waste? I figured they wont hurt, right? If I don't gain any performance, at least a good dog step....

9x7 prop should be the ticket. I have to believe that is a tall transom, or it is a very worn prop, thus your lower speeds? I have actually thought of a lightweight 18' riveted hull but they are hard to find- see the alumacraft makes one with a 20" transom and I have yet to find one that comes with a short transom. Makes a big difference. Get a tiny tach and post your rpms; recommend setting throttle at 4400 rpms out of water. New plugs are probably in order, do a fuel system check. Let us know, potentially a good rig/combo IMO.

Thanks guys. I ordered the 9x7 from backwater. We will see this weekend. I will try to take a video if it doesn't go well

If that 18' riveted hull does not work out, I am interested in it.

Ok will let you know. What are you willing to pay? It's extremely clean. No leaks or dents.

You stated it was a new hull, 2014 or 2015 ?, mfg.? transom height? open floor, benches/how many?gauge? Let me know either way, I can't find the 1848 (except for alumacraft's 1848/20 and there are no specs on their site!), so I am curious who still makes one? As much as I would like a hull like that, I hope it works out with the new prop, it should.

I got a new alumacraft 1848 in 2013 with a 20" transom and I was told they are no longer making this boat. I run a 20hp GDLT and it runs just fine. I bent the cav plate up pretty good and the prop will stay in the water. It will run 16-17mph with my bowfishing gear.

ottertailriverrunner, you have a good lightweight hull. A friend ran an old seanymph 1752 riveted jon with a 25 LT for several years, fighting with the tiller to keep the prop submerged because it was a high transom. He finally listened to me and cut the transom down to 16" and it was night and day. Because of his health problems, he switched to a 35 MB Hyper surface drive and it did fine, albeit that motor has required several repairs, and it developed a crack in the transom which was fixed and the transom beefed up. Those riveted hulls will last a lifetime and more, unless abused. Those speeds with the 20 HP your posted are dang good- imagine what you'll get with a 27/35/37 LT!

I have thought about cutting the transom down but I never really make long runs, maybe a mile or two, otherwise I would cut it down. I would like to get a 35hp but I don't know if a rivited boat would last.

As noted in my last post, a riveted hull will last a lifetime if not abused. If you don't have stumps, regularly jump beaver dams, or purposely go full tilt boogie over other obstructions, they are fine. For the 35 Briggs, which is heavier, it is wise to re-inforce the transom to avoid cracks and the like. Many of the riveted hulls have some wood in the transom and thus is subject to rot- but this can be fixed. Adding another strip of alum (say, 1/4") along the transom, or simply a secondary inverted U-piece over the area where your motor clamp goes, thereby stiffening the transom, should go a long way to prevent problems. The addition of Gatorglide or Steelflex on the bottom will, along with reducing friction and making trailering/untrailering easier, seal up more firmly any bottom rivets. Of course if you have such short runs as you stated, any speed increase is secondary. I regularly run 10-12 miles on my usual roundtrip duck hunts, but do not face any underwater barriers as I described, but desire a lighter weight hull because a thicker one does not afford any advantages. An extra 200 lbs. will easily be noted when you get stuck.

Alright guys thank you for your help! Put the 9x7 on from backwater and it's running great. Haven't even moved the gas tank and battery yet and it's planning out awesome and speeds are incredible. 22 mph empty. With that said, I think there is still room for improvement. I played with the throttle today and getting 4380 rpm out of the water. If I have the prop buried under, I'm only getting 3550 rpm. What can I do for this?

Go to a 9x6.

Those speeds are great, but it sounds like you'd still get that, and get better push in mud or crud by dropping to a 9x6.

You think backwater will take the 9x7 on return? I only ran it for about 20 minutes. Is it worth trying to put spark plugs and cleaning the carb first? Sometimes it seems like the engine runs a little rough.

Is a 10x5 worth trying as well?

Nah, probably not. That's a lot of prop for a 31 that's only turning a 9x7 at 3550. I could be wrong, have been many times before, but the 9x6 ought to put him where he needs to be.

This is just food for thought. After explaining my rig to the guys at backwater(1648 weldbilt 500# boat) we came to the conclusion that on a 22hp 72" shaft the 9x5 would suit it best. So I'm betting for you the 9x6 would be money. But as stated by others. They told me I could try the 9x6 and send it back for the 9x5 if it was too much prop

Sent from...wait, Where am I?

The 9x6 was usually perfect on the 24, but when we ran a heavier load we switched to the 9x5. Seemed to work great. The 31 is lugging to much with the 9x7, I bet the 9x6 will work great here too. I've seen where the 9x7 was fine on the 29 Kawa lt. But he had it on a 1760 that was a tin can. That thing was a beast on that boat.

A 9x6 is what I run on a honda 24 hp on my 18x50 mud hull. My prop has some wear, but I turn 3850 solo at 18/19 mph. If your 31 is a vanguard, you have 200cc more than I. I would go over all of the motor and do all of your maintenance (check valves, clean carb, check/clean coils).

With such a drop in rpm I would assume the engine is not getting steady fuel or it's not breathing well enough to make any torque up at those RPM's.

B coonass had an old gdlt 31 that was running 30+ on a 1740 skiff. It was modded, but u can dig through some old posts and find what prop he ran.