With or no lip

[Lakeman (Allison)]

I have a 1997 Allison (2003) with a 1996 175 FS. When i let off the gas at speed my bow come up a little. (maybe 6-8in to a foot high) Like to know why.

 

[GFinch]

Negative trim angle.
Propeller type.

 

[badbait]

This is only my opinion from testing setups on my 2003. I've found that if you have more setback than you need you may be getting all the lift you need and still be running negative trim. The negative trim is needed to hold the bow down because of to much setback. As soon as you let up on the gas at speed the motor quits pushing the bow down and up it comes for an instant until the water pulls it back down. My boat does the same thing when I take the trolling motor off. I checked the trim gauge and sure enough I am running negative trim without the trolling motor. If you have a trim gauge it would be easy to find out if this is what is happening in your case. Just tap down on the trim before you let up on the gas and this should solve it.

 

[Lakeman (Allison)]

Do anybody know why it do that. I would like to know. Would something be wrong with the boat or the motor... Can anybody help me.

 

[Lakeman (Allison)]

I can have the trim 1/4 - 1/2 and it still dose it, but not as bad. With 12in. setback..

 

[chad202]

Are you running a Tempest?

 

[Lakeman (Allison)]

No, Running a 28 raker that has been reworked by DAH.

 

[chad202]

have you tried a different prop?

 

[Lakeman (Allison)]

I have a 28 masco re3 and it the same way. I think it's not is bad.

 

[Lakeman (Allison)]

Would i need to go to 14in setback.

 

[chad202]

Measure the lip. you may have way too much for some reason.

 

[Lakeman (Allison)]

OK, I will do that sunday. Let you know tomorrow..

 

[K-DAWG XB 2003]

Mine does that with the Mazco HP4. As soon as I let off and start to slow down it feels like the hull pops loose and climbs up higher on the pad for a few seconds before it settles back down. It doesnt do this with any other prop I have ran. I figured it was cause the prop had lots of transom lift.

 

[props4u2]

Any over and through or through hub exhaust prop I have ever ran will drive the nose down when you floor it while up on plane even with a neutral trim, as you pick up speed the bow will lift as it should but if you let off before the prop has a chance to hook up the bow will rise when you let off. I take it you are running a stock lower unit deep in the water, with that and a through hub prop you are getting a lot of tail lift as the prop is trying to walk to the surface. The prop may also need more cup so it will hook up better. A bow lifting when letting off the gas is also a sure sign the prop is not hooked up.


Lee

 

[Lakeman (Allison)]

props4u2 - I bought the boat used about 6 yrs. ago. He got the it up to 78 mph. gps. I got it up to 82 gps. @ (6100 - 6300 rpm).. (motor was 1 1/4 - 1 1/2 below the pad) With wot. (on the pad) the bow did not go up when i let off the gas. My motor has lost sume power. It runs 71 mph. now with the same load. But that should not change anything should it.. I"am running a Bob's nose cone (The Combo) I guess the lower unit is stock. 12in setback, 1 3/4 - 2" below the pad. (at 5800 - 6000 rpm) I had the prop rework so it would run 5800-6000 rpm.. To get 71 mph.

 

[Lakeman (Allison)]

K-DAWG XB 2003 -- The same way your is doing..

 

[Lakeman (Allison)]

K-DAWG XB 2003 -- Is Kingsland, GA. near lake murry sc.

 

[mtolley]

Id try raising the engine. 2" under sounds way too low to me. Ive never noticed mine doing this before ,but ill be sure to look for it next time out. mt

 

[Lakeman (Allison)]

Running 71-72 mph. now. If i go up much less than 2" it will come out of the water and lose speed. But when it was running 82 i could run it 1 1/4 or so..

 

[Ronnie]

From what Darris told me a raker is a bad choice on any allison because it shoves the bow down.