Hi,
I have a 07 18' Tracker Tundra DC with a 150hp Mercury Opti-Max o/b, I have a 21 pitch 14 5/8 Dia. Tempest Plus Prop on it. By myself with no gear and at wot I am turning 5200 rpm trimmed all the way up and my max speed is approx 51-52 mph gps. This 150 opti's range at wot should be between 5250 and 5750 rpm! I have checked with Tracker and they are telling me that I have the correct prop and the motor is mounted properly which is the second hole from the top. I also have a chine-walking issue which happens at wot loaded or not but mostly when I'm lite. My main concern at this time is to try and get my rpm's into range and my speed up to what it's spec'd out at, the chine-walk issue could possible be related! Can anybody that has the same boat or similar give me any tips that could help me out! By the way I have one other piece of info, the cavitation plate is approx 1" above the bottom the hull. This is the reason I don't just lift my motor a notch. I would like to be sure before doing that, I do not have a water pressure gauge and don't want to take a chance and overheat it!


Thanks,

Al

had a older one same rpm and chinewalk maybe try a lower pitch prop 19pitch less top end more rpms

If you're only running the cav plate 1 inch above the bottom on a 50 mph plus boat you will get chine walk. I run a 17-1/2 ft Starcraft with Opti 150 and 21 Tempest. I just went out and measured and my cav plate is 5 inches above the bottom. It doesn't get any chine till it's running above 58 mph. I run 62 moph top end with the 21 Tempest at about 5700 rpm. If you don't want to raise the engine up then drop to a 19 pitch Tempest and live with the chine walk. If you switch to a 19 Trophy Plus instead you will reduce the chine walk by about 1/2 that of the Tempest. The only things that will reduce chine walk are trimming in, raising the motor up, shifting loads around in the boat to balance it side to side, or adding more blades to the prop.
Doug

Thanks for that info Bud,

I'm curious when you took that measurment, was the boat level and the motor vertical? Also, how does your motor get the water needed to keep it from overheating, have you done some modification to the pickup? My pickup start approx. 1 1/4 " below the cavitation plate!

Raising the motor was my first thought, but them I recieved mix information from people I thought should know about this kind of stuff, I was even told that by lowering my motor I would increase my rpm and speed because it would grab more water LOL!!!

Since you have a tempest prop, have you removed any of the 3 vent plugs on the sides of the prop? I was also told that by removing one or more of these plugs it will improve hole shot and increase the rpms. I really don't want to lose any speed, this boat and motor combo is rated to do between 55-57mph! If I drop to a 19 pitch prop I would definetly increase my rpm's but lose my top end speed!!!

Al

Experiment a little, does the Tundra have a stepped transom? My Tuffy does and my cav plate is quite a bit higher than the bottom.

Possibly a REV 4 19p would help your chine walk, and you could play with engine height, maybe raise one hole, dealer settings are pretty generic

Actually, at 5 inches above the bottom my rig is still a long ways from where some of the high performance hulls run. This is measured with the motor trimmed so the cav plate is parallel to the bottom. It is not uncommon for high speed rigs to run with the centerline of the prop shaft even with the bottom, or even 1 to 1.5 inches above the bottom. As the water comes past the edge of the bottom it comes up a few inches- since the boat itself has displaced the water around it. Hence, at the height I run there is no water pressure issue with a modern engine. You'll know when you've gone as high as you can- the prop will start to vent on turns and sometimes vent when running at cruise speed with a cross wind. You just drop down down 1 hole from that setting- or you have the prop blueprinted to add a little bit more bite. My Tempest runs one of the large hole PVS plugs and 2 of the medium hole plugs- stamped on the plug with a -L for large and -M for medium. Stock plugs were 3 -L, so I actually dropped the PVS area for this particular prop and rigging. Set the plug area by preparing for a completely normal start from idle, bump the throttle up to 3500 rpm- and don't touch anything. When the boat comes on plane let it run until it has reached a steady planing speed- don't touch the trim or throttle- and note the final rpm reached. If it's less than the 3500 rpm you initially started at- then you need to reduce the PVS plug size. If it's more than 3500 rpm then you need to increase the hole size. This should set your plug area just about perfectly. I usually try to set up with 1 plug bigger than the others- this seems to give a smoother running motor during the hole shot. I like the Tempest props for top end and overall good performance. The 4 blade Trophy Plus will handle better and steer easier, but you'll lose 1 mph or so on top end. I run the 21 Tempest during spring and fall, a 21 Trophy Plus during the summer and fall Musky season, and a 23 Trophy Plus that is radically modified when I'm not fishing and running light- looking for off-shore boats that I can ambush!
Doug

Yes, the transom on the Tundra is steped!

I will measure mine and let you know, mine has about a 6" setback or step

Hey Staylor, I'm definitely Raising the motor now! One last question about setting the prop vent plugs, my plugs have the letter "L" stamped on them so they are the large size, when you do the plug test and bring the rpm's up to 3500 is the motor trimmed in completely?

Thanks again for all the info, I'll let you know how made out!

Al

Staylor,

What is your prop shaft to pad measurement? Is your boat a bass boat or a Deep V walleye boat. A stock 150 opti does not have nose cone pickups. Are you running a stock setup? A water pressure gauge is what most bass boats rely on when moving an engine that high. You wouldn't want to over heat your motor through trial and error. I know the Tundra has a fiberglass like hull, but the boat still weighs 1600lbs with a 25" transon height. I am sure you can get a few more mph out it by tweaking the setup, but 60mph would be difficult. Most low profile bass boats that weigh less just make it over 60mph with a stock 150 opti.

Staylor,

What is your prop shaft to pad measurement? Is your boat a bass boat or a Deep V walleye boat. A stock 150 opti does not have nose cone pickups. Are you running a stock setup? A water pressure gauge is what most bass boats rely on when moving an engine that high. You wouldn't want to over heat your motor through trial and error. I know the Tundra has a fiberglass like hull, but the boat still weighs 1600lbs with a 25" transon height. I am sure you can get a few more mph out it by tweaking the setup, but 60mph would be difficult. Most low profile bass boats that weigh less just make it over 60mph with a stock 150 opti.

For setting up the PVS plugs you start with the motor wherever you normally like it for hole shot- and you do not touch the trim at all when looking for the rpm the boat reaches when its fully on plane- and let it sit on plane for at least a minute or so since sometimes that last 50-100 rpm comes up slowly. On my rig with a Merc Smartcraft 0-10 trim gage I usually holeshot at my normal setting of 1 on the gage, so I'm trimmed in almost all the way for holeshot.
Doug

My present rig is a Starcraft Superfisherman 176, single console. This is a tin boat, with a 17 degree deadrise at the transom- thus it is not a pad boat- its almost a deep vee, using the old criteria of a deep vee hulll having at least 20 degrees deadrise. Hull weight is 1140 dry, so it's lighter than most bass boats of the same size- except for go fast bass boats like the Allison. A vee hull can normally run the motor a bit higher than a pad boat, simply because the vee runs a bit deeper in the water. On my rig, my cav plate is 5 inches up, I've run prop shaft heights or anywhere from the stock 6 inches below to as high as 3 inches below. This is more than enough water to feed a stock opti- and you would never run a cone on a 60 mph walleye boat unless you want to lose 3-4 mph. If I could run with the prop shaft as close to 1 inch from the bottom- which you can't do successfully on a 60 mph boat, then I would simply plug some of the pickup holes in the lower before I'd put on a cone. I do indeed have a water pressure gage- and the Opti shows no drop in pressure at all running the prop shaft 3 inches down. The boat in question here has the motor only 2 holes up- essentially fully buried, and going up another hole or two with his cav plate currently 1 inch up is not going to drop the pressure. If he added a jackplate and wanted to go higher than the holes in the motor would allow- then sure, he should keep an eye on pressure- except that a 60 mph boat 1600 lb boat will have the prop start venting like crazy long before he could get the motor jacked high enough to cause problems. I agree with you that the typical heavy 18 ft bass boat w/150 Opti will have trouble getting to 60, but I've brushed 63 gps with my lighter Starcraft w/150 and a really decent set-up which took 3 years to finalize. For Fishergrn's rig, I think that high 50s is a good possibility- maybe even 60 if everything is working right. In any event, the only way to see what's possible is to experiment. Heck, my Starcraft dealer said I'd never break 55- even when he knew my last rig was a 21 ft 1700 lb Checkmate w/7 inch pad, that was running a solid 72 gps with a tired 8 year old 225 Evinrude c carb motor.
Doug

OK, measured my engine hieght with a built in 6" set back, bottom of the boat and the outboard cavitation plate level, the hieght is 7".

The engine on my boat is mounted in the middle hole.

I am running a 21 REV 4

Thanks for that info Moreyes and Staylor. I'll post how I made out, I'm going to make the changes and test it this weekend!!!!!

Al

I had an 04 tundra/175 opti and only got 52 out of it with some tweeking. I was running a 21 mirage at 5600rpm.

I ran a Tundra 18 last year and found the best handling prop was a REV 4 19p on that hull. The Tempest props seem to have to much bite and really increased the chine walk. I never raised the motor, but I am sure it could go up all the way as you could not even come close to blowing out when trimmed all the way out in tight turns at full throttle. With a 175 opti and a full tourney load the 18 Tundra would run 52mph wit the Rev 4 19p.

Hey guys, I raised my motor two holes and tested my boat today! Just to refresh your memory, I originally was turning 5200 rpm's at 52 mph gps with a 21 pitch Tempest prop, Now I am turning 5400 rpm's and just shy of 54 mph gps! The boat seems to ride better but still chine-walking when fully trimmed and approaches 53 mph. The walk disappears once you trim down just a hair! The boat shows no sign of blow out even in a hard turn which makes me think that I can still raise my motor to the last hole in an attempt to increase rpm and speed! What's your thoughts on this guys???

Al

I have the same setup as you but in a 04 tundra. I had the same results as you - my speed matched my rpm(5200=52mph) I am running a 21 Lazer II that came on the boat 5400rpm=54mph. With this prop I have seen 57 mph with light load and lower elevation. This is with a 6" jackplate - shaft 3" below pad. Here are results of 3 props I tried.
21 Lazer II 54 @5400
19 Tempesr 5600 @52
19 Lazer II 5500 @53

Yes, try and raise it one more, that is what I did I found that I was to high eventually, and droped it one then.



Hey guys, I raised my motor two holes and tested my boat today! Just to refresh your memory, I originally was turning 5200 rpm's at 52 mph gps with a 21 pitch Tempest prop, Now I am turning 5400 rpm's and just shy of 54 mph gps! The boat seems to ride better but still chine-walking when fully trimmed and approaches 53 mph. The walk disappears once you trim down just a hair! The boat shows no sign of blow out even in a hard turn which makes me think that I can still raise my motor to the last hole in an attempt to increase rpm and speed! What's your thoughts on this guys???

Al

...since it sounds like you're on the right track. The small block Optis seem to have a "sweet spot" right around 5500 to 5600 rpm where they're at max power, and going up another notch may get you right there. Also, when going for top end try this old racers trick- get to full throttle with moderate trim, then try trimmimg up just a bit until the chine walk starts, then trim down a hair until it stops, then trim up again. This method fully loosens the hull from the water and gives you a little bit of feel for the chine walk. A second trick is that when the walk starts, put the boat in a very slight left turn and see if this preloading of the rig reduces the chine. This is not as easy to do with hydraulic steering as it is with the older style dual cable steering systems that can be adjusted to zero play. And, if you're running hydraulic steering, make sure your system is well bled of air and the adjustment to take out slack at the transom brackets is done properly. I run Sea Star, and find this is done best by turning the adjustment to remove play, then pushing back and forth on the cav plate with one hand, while trying to torque the adjusting ring a little bit tighter with the other hand. Whatever you do- never try to drive thru chine walk with hydraulic steering or any of the no feed back systems. With dual cables you can use bump steering to the left to counter the chine, but this does not work with the other types- bump steering is also something that takes a lot of driving hours to get a feel for. The last trick is to note if you've got any steering torque left or right when at top speed. If you do, then remove this by either adjusting the tab- or adding a skeg mounted torque tab to the lower unit. If you rig runs the flat plate instead of a tab, you can buy the merc high performance tab normally used on I/Os which will bolt right on and will clear the high rake blades of the Tempest. I use the flat plate and a Land and Sea Torque Tab on the Opti's skeg, shortened by testing and cutting its length until I have neutral steering torque. Playing with the tab reduces what's called the motor's crab angle- which reduces chine walk and often adds another 1 mph to the top end.
Doug

Hey Staylor, I'm going to raise it one more time which will put the cavitation plate up appox 3 1/2 " higher then the bottom of the hull. Hopfully my custom cover still fits... LOL! I have the dual cable steering setup and I'm going to try and tighten it a little more then what I have already. I guess if it continues, I'm just going to try and drive thru the chine when it happens! By the way I tried the vent glug test and found my rpm's increased to just over 4000, I have the "L" large size plugs in it right now, would I just remove them one at a time and try it or do they sell an extra large plug?

Al

..no plug at all. Pop them out one at a time. Since you have dual cables, you can bump steer and counter the chine. You only bump left, and it's just a tiny bump left when the hull tries to rock to the right. You have to do this at a fairly fast pace- but since its a tiny motion you actually get used to doing it fairly easily.
Doug

I am not a tracker owner but here is the best way to see if you have your engine height dialed in correctly..http://www.veradoclub.com/smf/index.php?topic=137.0\

Nice visual:exactly:

On just about any walleye boat running with the motor mounted all the way down you'll see the cav plate if you're running above 40 mph- so the visual technique shown is useless. The method shown is fine if you've got an offshore hull and don't know squat about set-up. I see many offshore style hulls up here in Buffalo- the ones that do "faster than 80" used to lose badly to my 72 mph Checkmate, the ones that "do 70+" seem to fall behind my 62 mph Starcraft really quickly. Only about one boat in every 20 I see appears to have the engines raised to the proper level for the hull type and speed they run at. When I used to race outboards back in the 1960s we used to use 1/16 inch shims to set engine height for max speed- and you could readily see and feel the difference with only one shim added or subtracted. This is why so many bass boats are running hydraulic jack plates with height gages- so they can extract every last mph from the rig by tweeking the engine height.
Doug

Staylor, you are suppose to check the plate at a cruizing speed, 38-4200 rpms.. MOst guys on this site are not going to screw around with 1/16" shims. We want to be in on the water not in the garage... This is the way that the merc racing team advises setting up your boat... I am guessing that the merc racing team know alittle more than you about setting up a boat...:boxing: and obviously the merc guys do more than that but not many guys are going to go to that extent... The viewers here can decide and I am willing to bet most of them are going to be going my route since it is quick and easy-brad

That may be how some people choose to set up the offshore rig with three Verado monster motors that is pictured at the link you list- but that's not how you set up a walleye boat. You can also rest assured that the Merc Factory guys do a lot more when setting engine height then looking back in the water at the cav plate- but if you want to believe that looking at a plate is better than measuring things then thats fine with me. And, by the way, if you've ever run a boat with a hydraulic jack plate and set the plate while running for max speed- those last few twitches of the plate are indeed 1/16 increments or less. How someone chooses to set up a fishing boat is up to that person. In this thread I'm simply helping a guy who wants a few more mph out of his rig- and he's gaining some speed. If he wants to have his rig get to the fishin hole faster than it used to that's his business. If you want to leave your boat with a factory set up thats slow and uses more fuel than a properly set up rig- then that's your choice. Heck, you may as well run fixed trim and a bronze prop too- you can even skip the tach....you can listen for the right rpm.....it's just like setting motor height by looking at the cav plate.
Doug

most guys are not going to screw around with shims and measuring. This is a good quick way to adjust engine height..3 engines or 1....We want to fish not sit in the garage. I have posted this and has helped a ton of guys out and I always get thank yous from people...Yes you can make it more difficult if you want to do nothing but go fast but like I said most of us want to fish...Not wrench..

Obviously the merc guys do more than that but not many guys are going to go to that extent... The viewers here can decide and I am willing to bet most of them are going to be going my route since it is quick and easy-brad

Hey guys, I actually tried that look test originally! For one thing, I assumed that you were to check the cavitation plate when trimmed out and at WOT! Well, when I swithched seats with my wife and walked to the back to a look at the plate the boat went into a aggressive chine-walk and almost through me from the boat!!! Before that happened I did get a look at my cavitation plate and it looked like it was set up properly. But, as Staylor nows I have raised my motor over 2 1/2" since and my performance has only improved! So, I don't think that it works for every boat configuration. Although, I really appreciate everyone's input in trying to help me out, after all this is what this message board is all about!!!

Thanks again to all,

Al

I just want everyone involved that gave me suggestions and to those who were really helpful the final results! I tested my boat on saturday after raising it as far up as the mounting holes would allow, I had a top speed of 54.7 mph gps and an rpm of 5500. I also noticed that the chine-walk became controlable with a couple of counter steer motions and had no signs of the motor blowing out! I'm extremely happy with these results, the boat is performing up to the posted spec. I'm almost tempted to through on a jack plate and see what this boat is capable of!!!

A special thanks to Staylor for his time spent on his detailed replies, he help me immensely!!!

Al

Tachs sometimes are off a bit.... you know?

Glad it worked out for you- if you're happy then I'm happy too. If you ever do add the jack plate post the results here- and monitor your water pressure if you raise her up on the plate. If the pressure starts to waver or run low then you'll need to plug some of the intake holes on the lower unit to maintain pressure. You also might have another mph or so available from having the prop blueprinted and having the cup altered to suit what your rig needs. This is a bit of a crap shoot though- it costs roughly $200 and sometimes it works- sometimes it doesn't since a Tempest is a pretty darned good prop out of the box. Your slip has remained pretty constant on the prop as you've raised the engine, so its still hooking up well. As you've seen, the best thing about raising the motor is that it reduces the chine walk so you can drive the boat a lot easier- and if you can't drive the boat because of the chine walk you'll never be at the rig's full potential.
Doug

I would stick with what you have, skip the jack plate