tracker porpoise

[marcengillb]

I have a 1995 bass tracker pro 18 if you bump the trim more than once it starts jumping like a bull.is there anything I can do to help this,90hp merc 3 blade prop 4800rpms 48mph,23 pitch,will a lower pitch prop help,I dont know my max rpms,my tach has no red line.

 

[LubeDude]

Re: tracker porpoise

Is this your boat or similar?<br /><br />

<br /><br />If the 4,800 is your WOT RPM at full trim, you are teribly over propped. Also you wont be able to trim much if you are not at near WOT when you try.

 

[marcengillb]

Re: tracker porpoise

That baat is a v hull ,mine is a modified v .But the problem would be the same with both.Seems to me I should need about a 19 pitch prop,but I dont know my max rpms,my tach has no red line,do you know max rpms on a 95 90hp merc?I dont think a stingray would help at trim .do you? Alsowhen I got this boat it had two cranking batteries,one for the starter only the other for acc.The trolling batt.is in the front.I dont think it came this way new.Ive got to figure out how to run my trolling motor wires from the back.

 

[marcengillb]

Re: tracker porpoise

That baat is a v hull ,mine is a modified v .But the problem would be the same with both.Seems to me I should need about a 19 pitch prop,but I dont know my max rpms,my tach has no red line,do you know max rpms on a 95 90hp merc?I dont think a stingray would help at trim .do you? Alsowhen I got this boat it had two cranking batteries,one for the starter only the other for acc.The trolling batt.is in the front.I dont think it came this way new.Ive got to figure out how to run my trolling motor wires from the back.

 

[LubeDude]

Re: tracker porpoise

This is my take on porposing, and it doesnt always hold true. Ive been around Bass boats for about 25+ years so here goes.<br /><br />If you are haveing problems, sometimes its too much weight in the front, and sometimes its just the oposite. It has a lot to do with how much HP you have also. Take my boat for instance, its about 17 1/2' and has a 150 HP engine. If Im running about 35 MPH, I cant trim but maybe a click or so and it will porpose. The faster I go the more I can trim. At WOT I can trimm out all the way with out any porposing. Then I back it down just a bump and it hooks up. Now if this same boat was under powered, say it had a 115 instead of the 150, I am sure that I couldnt trim all the way with out some porposing problems. It takes a huge amount of HP to hold the front of the boat out of the water. Whe you dont have enough for the weight it falls down. Therefore I think you need to get that battery out of the front of your boat. Just remove it and place it in the back and go for a ride and see if it is worse or better. Mine is better when I dont have the bass seat and my tackle bag up front. That probably takes away about 75#s off the nose. If I take out all the bass seats, all the tackle and Im alone in the boat I get almost another 5 MPH. Now if I could drop that extra 50#s. <br /><br />Also, smart tabs will help you greatly, but thats another issue.

 

[cwilt]

Re: tracker porpoise

hey marcen<br /><br />i have a 1994 and newer service manual for mercs and your max throttle rpm range is 5000 to 5500 rpms.