mattp33 Posted November 10, 2014 Report Share Posted November 10, 2014 Hey guys Buddy of mine just got a 2007 tracker V18 Sport with a 115 Opti on the back, nice rig!!! ( for an aluminum Deep V We are having some problems tho.... Issue is this, boat needs to be trimmed all the way down to get it out of the water, once on plane the trim is all the way down and as soon as he tries to trim it up to gain some speed the RPM's jump past 6000 and over rev warning comes on. Prop is a 13x19p aluminum, WOT he gets 34MPH at 5500 RPM (they claim to get 45mph with this set up?) As soon as he tries to trim up we get and over rev Cav plate it 1 inch above transome, he also tried 1 of those fins on the back but didn't change anything. Why can't we get the nose up and out of the water? Any thoughts guys? Thanks Link to comment Share on other sites More sharing options...
BillM Posted November 10, 2014 Report Share Posted November 10, 2014 You need a different prop, give Kawartha Prop a call, tell them what you've got and they'll give you their recommendation. Link to comment Share on other sites More sharing options...
mattp33 Posted November 10, 2014 Author Report Share Posted November 10, 2014 You need a different prop, give Kawartha Prop a call, tell them what you've got and they'll give you their recommendation. I was thinking prop too!!! I have a Lazer 2 13.5 x 22P I could lend him to try, dont think its a good match for that boat tho Link to comment Share on other sites More sharing options...
cheaptackle Posted November 10, 2014 Report Share Posted November 10, 2014 Double check that cav plate height - you said 1 inch above transom - think it's supposed to be below, mention it to them when you are checking into prop recommendations. Michael Link to comment Share on other sites More sharing options...
DRIFTER_016 Posted November 10, 2014 Report Share Posted November 10, 2014 Double check that cav plate height - you said 1 inch above transom - think it's supposed to be below, mention it to them when you are checking into prop recommendations. Michael Yep, I believe it's supposed to be even to 1" below. Might have to lower the motor a hole. Link to comment Share on other sites More sharing options...
Terry Posted November 10, 2014 Report Share Posted November 10, 2014 i think he should buy a new hub for the prop Link to comment Share on other sites More sharing options...
mattp33 Posted November 10, 2014 Author Report Share Posted November 10, 2014 WOW Kawartha Prob is amazing!!! Guy help me out bigtime. Time to go see him for a couple of props! Thanks again Link to comment Share on other sites More sharing options...
Lape0019 Posted November 10, 2014 Report Share Posted November 10, 2014 if a 21p prop doesn't help (it sounds like your prop might me too low in pitch) the motor may be too high. What hole is the motor mounted in? Link to comment Share on other sites More sharing options...
Fisherman Posted November 10, 2014 Report Share Posted November 10, 2014 What Drifter_016 said, he's sucking air when trimmed up and the prop can't dig the water. Link to comment Share on other sites More sharing options...
NANUK Posted November 11, 2014 Report Share Posted November 11, 2014 I think you need a bigger prop with higher pitch, I would start with with 14x21 and go from there. pobably need a 15 inch prop with 23 pitch. Link to comment Share on other sites More sharing options...
irishfield Posted November 11, 2014 Report Share Posted November 11, 2014 As many have already pointed out... that things called a cavitation plate for a reason. That and what Terry pointed out... put some muscle on that prop and see if the hub slips! Link to comment Share on other sites More sharing options...
mattp33 Posted November 11, 2014 Author Report Share Posted November 11, 2014 if a 21p prop doesn't help (it sounds like your prop might me too low in pitch) the motor may be too high. What hole is the motor mounted in?The motor is in the second lowest hole position. We are going to instal my prop tomorrow and do a test run. I run a laser 2 13.5x22p see if that helps. It may also get dropped to the lowest hole. I find it hard to believe in the past 7 years ans 2 other owners have not tried to figure this out IRISH: terry also mentioned something about the hub, never thought about it slipping? To think about it I noticed the lock ring was loose and would rattle around. Could this be as simple as a bad hub or loose bolt? Did we really over think this 1 Link to comment Share on other sites More sharing options...
irishfield Posted November 11, 2014 Report Share Posted November 11, 2014 (edited) My prop hub is two pieces of rubber and it's designed to let go on a strike, etc. If that nut is loose.. then it's very possible that he hub is disengaging under load. I'd be pulling the prop off first... well after I put the engine in gear and then tried forcing the prop to turn first. If the hub shows signs of letting you do so, I'd lay bets you've chewed the prop hub out. Edited November 11, 2014 by irishfield Link to comment Share on other sites More sharing options...
mattp33 Posted November 11, 2014 Author Report Share Posted November 11, 2014 My prop hub is two pieces of rubber and it's designed to let go on a strike, etc. If that nut is loose.. then it's very possible that he hub is disengaging under load. I'd be pulling the prop off first... well after I put the engine in gear and then tried forcing the prop to turn first. If the hub shows signs of letting you do so, I'd lay bets you've chewed the prop hub out. That also answers my next question of how to check it thank you. I guess I thought most of the load would come on accelerating out of the whole. Will post our results tomorrow. Thanks again guys Link to comment Share on other sites More sharing options...
DRIFTER_016 Posted November 11, 2014 Report Share Posted November 11, 2014 The prop nut should be torqued to 55 foot pounds on that motor. Depending on the type of prop it will either have a built in hub or a Torq Flow hub. The built in hub is rubber while the Torq Flow hub is easily replaceable and made of plastic. Link to comment Share on other sites More sharing options...
mattp33 Posted November 12, 2014 Author Report Share Posted November 12, 2014 So...we tested my laser 2 13.5x22 prop on this boat yesterday and here are the results. (not what I thought) Holeshot-Crappy but got us out, much slower than the 19P Mid-Range-We had great mid range torque Top end-Only gained 1 mph RPM-slight decrease (maybe 150RPM) Trim-We had a little more trim before we lost traction, got it almost to level before cavitataion started I really expected to gain a lot more on the top end. Will this boat really only do 35mph, I would expect at least 40mph out if her. Feels like the hull is glued to the water! Link to comment Share on other sites More sharing options...
Steve Posted November 12, 2014 Report Share Posted November 12, 2014 is it because you are only powering to just over 2/3's of the hull's max power? that boat is rated for a 150. Link to comment Share on other sites More sharing options...
Steve Posted November 12, 2014 Report Share Posted November 12, 2014 here's a test result for that hull: Our test rig was outfitted with a Mercury 125 outboard with a 12 ½ by 23 aluminum prop. When we tested the Tracker Tournament V-18, we found she climbed up on plane in only 3.9 seconds. When we tested speed, she was consistently at 30 mph in only 7.3 seconds. We found her best cruise to be at 3500 rpms which registered 38.7mph on our Stalker Pro radar gun. At cruise, she burns 6 gallons per hour and has a sound level of 82 dBa at the helm. We achieved a top speed 45.5 mph turning 5400 rpms. At this speed she burned 11.9gph and had a sound level of 94 dBa at the helm. Cruise range was 176 miles and top speed range was 141 miles on her 41 gallon fuel tank. Link to comment Share on other sites More sharing options...
DRIFTER_016 Posted November 12, 2014 Report Share Posted November 12, 2014 It doesn't help that your motor is too high on the transom. Drop it at least one hole and go test again. Unless you can trim the motor out you will not be able to lift enough of the bow of the boat out of the water to combat drag on the hull. Link to comment Share on other sites More sharing options...
captpierre Posted November 12, 2014 Report Share Posted November 12, 2014 (edited) Ya. I have a similar boat and HP. Should be getting 38-40mph. with that original prop RPMs are OK. Shouldn't cavitate when trim modestly My guess is motor too high. Not easy to change let us know. Jamie at kawartha prop is great He got me onto a 4 blade. hole shot better and fuel economy improved. trolling a bit faster. only down side Edited November 12, 2014 by captpierre Link to comment Share on other sites More sharing options...
mattp33 Posted November 12, 2014 Author Report Share Posted November 12, 2014 We are going to drop this motor down the 1 hole tonight and see what happend in the morning, I think we just need some air under this hull. Its "glued" down so hard that in a hard turn it almost pitched us right out of the boat. This thing rails corners lol Link to comment Share on other sites More sharing options...
DRIFTER_016 Posted November 12, 2014 Report Share Posted November 12, 2014 We are going to drop this motor down the 1 hole tonight and see what happend in the morning, I think we just need some air under this hull. Its "glued" down so hard that in a hard turn it almost pitched us right out of the boat. This thing rails corners lol Exactly!!! You are unable to trim up without cavitation and because of this can't get the bow up to reduce drag. Once you lower the motor you will be able to trim up higher and get more hull out of the water. Hopefully one hole drop will do the trick. Mine had the same issue when I put the jack plate on my boat. Ended up having to re-drill the plate to get the motor lower. It's still not as low as it should be so I'm losing a bit of performance. I think if I get it another inch lower I should be able to get another 4-5MPH out of the boat. I am going to have to remove the motor and jack plate and then re-drill new holes in my transom as it's currently as low as I can get it. I plan to replace my transom's core at the same time as it's a little on the soft side. Link to comment Share on other sites More sharing options...
Lape0019 Posted November 12, 2014 Report Share Posted November 12, 2014 I just checked the Mercury prop selector and a 13x19 seems to be what the recomend. You can check it here. https://www.mercurymarine.com/en/ca/propellers/selector/#/step-one By the looks of it, a theororetical top speed of 47mph would be attainable if you had absolutely no prop slip. As it stands right now, you prop slip is absolutely terrible at over 25%. This means your problem is most definitely setup. You are getting too much air around the prop so dropping the motor a hole is probably a great idea. My 75 Fourstroke with a slightly lower gear ratio will push my PT190 to 39-40mph (happened once for 40) and this is mounted in the second hole from the top. I do however have a shallower boat... Good luck and report back! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now