Raising the bow

[ppcshooter]

Hi all, <br />New to the forum hope this is in the right place.<br /><br />I have a 87 Sportcraft 22’ walk around with a 91 200 Johnson with a small problem. The boat gets up on plane good with no issues but the bow will flatten out when up to speed. I can trim the motor out to get it on top of the water within max RPM range but it just before the prop blows out. This makes also make the prop blow on the turns. The motor is really trimmed to the max, what can I do to? Motor height appears to be correct. It does not seem that trim tabs will help. Bow needs to go up not down. Will a hydrofoil work?

 

[tashasdaddy]

Re: Raising the bow

check for any soft spots in the floor, you could possibly have waterlogged foam under the floor

 

[jtexas]

Re: Raising the bow

Welcome to the forum!<br /><br />Move the mother-in-law from the front of the boat to the back? I mean, have ya thought about weight redistribution?

 

[ppcshooter]

Re: Raising the bow

No it’s not water logged, weight is 70 gal of fuel mid ship to rear, just the anchor up front and a few electronics at the helm and it tops out at 42-44mph Could it be just the hull design?.

 

[roscoe]

Re: Raising the bow

Hull design<br />Prop design<br />Engine height<br />Boat weight?<br /><br /><br />NO hydrofoils !!

 

[Chris1956]

Re: Raising the bow

PPC, Some hulls ride flat in the water. You can try to trim out the motor, but sometimes it has only a small effect. My old runabout had a straight Vee hull (did not flaten in the stern area) which rode "dead" flat in the water. The faster you went, the higher it rose in the water until the prop blew out. The prop also blew out in turns, sound familar?

 

[Dhadley]

Re: Raising the bow

Very typical of Sportcraft of that era. If you'll notice a lot were sold from the factory in that size range with smaller-than-desirable motors to keep the cost down. A lot of the 20's had V4 crossflows. So did some of the 22's or a small V6.<br /><br />In order to get the boat on plane quickly and easily with small hp motors they put a lot of hook in the hull. As the boat got older and maybe sold a couple of times someone wanted more power (who dont???). With more power you actually drive the nose down. The faster you go, the more the hook drives the nose down. It's doing it's job. We've run into this a lot "back in the day".<br /><br />We had some success with removing some hook. You have to be careful not to remove too much. A 1/4" is a lot and I remember one Sportcraft had almost a 1/2". Didn't even need a straightedge for that one!

 

[ppcshooter]

Re: Raising the bow

That makes sense.<br />The boat was originally rigged with twin 70 Evinrudes both RH rotation (What a pig). One finally took a dump when the previous owner had it. When I bought it I did not replace the 70. I replaced it with the single 200. I did notice that he bow does run deep in the water is this what you means by the hook? If so, I guess it is just going to be the nature of the beast. Sure would like to find a Grady hull cheap.<br />Thanks.

 

[deejaycee_2000]

Re: Raising the bow

Have you thought about putting trim fins on your motor?

 

[Texasmark]

Re: Raising the bow

D, That's interesting what you say about hook. 1/4" over a 20' boat is very slight. I always thought that when people say "hook" they mean hook. Live and learn.<br /><br />I agree on the hook causing the nose down problem.<br /><br />Other thing I noticed about boat designers (not familiar with this boat) is they sometimes bend the bow down (older Sea Ray 20ish foot deep V's for one). I know they do it to help improve visability, but I say heck with the visability. I want my nose up when I'm in rough water and the bent snauze defeats the purpose.<br /><br />My 2c.<br /><br />Mark