Need help fine tuning brand new Smoker Craft with Yamaha F115

[Larry3215]

I just picked up a brand new Smoker Craft Phantom 202 (not the offshore version) with a new Yamaha F115. The boat is 20' 2" with 93" beam, 17 deg dead rise, all welded hull and weighs 1650 lbs empty. The motor is mounted so the ventilation plate is about 1/2" above the V at the keel. I can drop it one hole or raise it up if needed.

Phantom 202 | American Angler by Smoker Craft

It came with a 13x19 prop which didnt perform at all well. Peak RPMs were in the 5500-5800 range with top speed in the 33-35 mph range. the slip calculated out to around 27%.

The dealer let us try a 13.25x17 prop and the results were much better.

RPMs dropped a bit to 5500-5600 and GPS speed went up to 36-37mph for a slip in the 12%-13% range.

Thats a big improvement, but Im still thinking there is room to do better. Im tempted to call this close enough except for three things.

1) The boat was only partially loaded - 1/2 tank of gas and no fishing gear, no kicker or spare battery, no downriggers etc. Our typical trip out will have an easy 300-400+ extra pounds in the boat.
2) The prop seems to be ventilating too easily when turning at speed when trimmed up. It does it at cruise speed (4000rpm/26mph) and full throttle.
3) The bow is riding too low on plane and at full speed. Its almost plowing even when trimmed up as far as it will go without ventilating. This model of boat has the windshield well forward and the splash line is about even with the windshield. Videos of this boat running show the splash line well back from where it is for us.

Based on what Ive read here Im thinking I need to do a few things:

1) Drop the pitch to get the peak RPMs up closer to 6000. Im guessing a 15 or 16 pitch?
2) Lower the motor one hole to help with the turning issue?
3) go to a larger diameter prop to help raise the bow up?

Before doing anything I will finish outfitting the boat so its at its full weight with all the gear mounted in its place and then re-test with this prop.

Im not concerned about top speed or hole shot but I am concerned about engine rpms and how it rides. Im pretty sure if I can get more hull up out of the water it will be better.

Any suggestions, comments, advice would be greatly appreciated!!

thanks

 

[jestor68]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

The Mercury prop selector calls for a 16 or 17 pitch based on weight and current performance. I used the weight from the web site:
boat/motor=2100, 800 lbs of people/gear, and 25 gal of gas.

As stated in the other thread, a SS prop would yield better over all performance and help to reduce the tendency to ventilate in turns.

The Merc Vengeance/Quicksilver Siverado 13-1/8 X 16 pitch seems the good choice for that application.

Keep in mind the specs for your motor: 115 hp @ 5800 rpm. Rev limit to 6300 rpm. So realistically, the ideal rpm range is 5800-6300.

Michigan aluminum props don't work as well as Solas or Turning Point. Actually; no other aluminum prop works as well as those two.

You still need to take the boat back to the dealer and have the service manager examine the hull for any irregularities.

 

[Larry3215]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

Thanks!! The boat is going back to them later this week to get the kicker mounted. We will go over all this at that time.

 

[Larry3215]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

I was just playing with the Mercury prop selector.

Thats a cool prop selector. But it doesnt like data outside its expectations

When I input the prop data for the prop that came with the boat originally, it will not let me select the actual boat speed we were getting at the rpm we were seeing. It wont go low enough on the speed. I guess it is assuming only a limited amount of slip is possible.

When I select the lowest speed they will allow, it recommends keeping the same diam/pitch prop that was originally on the boat.

Going by weight, which they say is less accurate, I get the same results you got.

We will probably not go the extra for an SS prop, so it looks like the 13.25x17 we have on there now is in the ball park at least. I will see if the dealer will let us up-grade to a better brand of prop.

 

[aaa1950]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

It was interesting reading the description of you ventilation problems. I have a 2012 Hurricane 188 Sun Deck Sport with a 2012 F115 Yamaha 4 stroke OB. I have similar problems with the motor venting, sometimes regardless of the trim, usually starts after trimming up on plane but once it starts I almost have to come to a complete stop to correct it. I don't go offshore, normally we are in a lake. It has a 13.25 x 17 3 blade stock prop and I am thinking of going to a 4 blade. A Hurricane rep has indicated the motor on my boat should be mounted in the second hole from the top, but when I bought it the motor was mounted in the top hole. Haven't done anything about that but the motor is scheduled for 100 hr service and I plan on talking with the shop about that. My WOT matches the performance bulletin from Yamaha, 6000 rpm at 38-40 mph. I am interested in what solution you come up with. I know the boats are different but any info helps.

 

[Larry3215]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

Im not at all sure if we can compare our boats. Like you said, they are so different.

That said, ours behaves very much like yours. Once it starts to slip, we have to back way off on power and/or trim way down to get the prop to bite again.

Have you tried moving weight to the back? Ours behaves much better with weight shifted to the stearn.

We just got our kicker mounted today. Im going to install the second battery tomorrow. We will do more water testing as soon as the weather allows. Im hoping the added weight in the back will help get the bow up more with less trim required. Im thinking that will help some with the ventilation problem and might get us a tad more top end - or at least keep the same top end even with the added weight.

So far Im thinking our bigger problem is the motor being on the small size for our size/weight of boat. Looking at the specs for your boat, I suspect that may be part of your problem as well - but thats just a wild guess based on some advice others have given me about our setup.

Our F115 is mounted in the second hole - as recommended my the boat mfg. When running on plane, the ventilation plate is right at the water line, so I dont really want to lower the motor for fear of loosing top end performance.

I doubt we will experiment with different props. The 13.25x17 is working much better than the original 19P prop and the numbers, while not great, are in the ball park on slip and rpm.

I'll let you know how it does after we get all the stuff on board and water tested again.

Oh - Im also installing a Tiny Tach TT2AM to use as an hour meter and to double check the tach that came with the boat.

 

[Georgesalmon]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

Think about a four blade. I got the new merc aluminum prop, pretty cheap and I like it. Can't remember what its called?

Edit" "Spitfire" is the name. Best AL prop I've ever used, got mine for about or a little under a $100 new on ebay.

 

[aaa1950]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

I'm almost sure I will switch to a 4 blade. I will also get the techs to check the ventilation plate position. I have two batteries for the trolling motor and the engine battery in the rear of the boat so I already have quite a bit of weight there and I do try to distribute weight as much as possible. You are right, different boats but some of the same problems. Right now I'm thinking of trying the new Turning Point Hustler 4 aluminium blade coming out any time now. I'm seeing a lot of good information on that brand. A 115 hp engine works well with my boat and I like it, but I do think both of us might have been better off with the 150 hp. It might be a little while but I will let you know how thing go. I think the exchange of information and ideas through this forum is a great tool.

 

[Larry3215]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

We like the F115 on our boat too - even if it is on the small side. Its worlds better than what we had before. The F115 pushing the new 20' boat gets roughly the same to maybe a hair better mileage than our old Evinrude 70 pushing our old 18' Sea Nymph - and it does it at higher speeds and much quieter. At trolling speeds it gets much better mileage.

The performance isnt stellar, but it is more than adequate for 3 old farts to go fishing

 

[Larry3215]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

Think about a four blade. I got the new merc aluminum prop, pretty cheap and I like it. Can't remember what its called?

Edit" "Spitfire" is the name. Best AL prop I've ever used, got mine for about or a little under a $100 new on ebay.

Thanks for the recommendation. jestor68 above recommended the Solas or Turning Point al props. Ive heard good things about both of those on these forums. We used a Solas 3 blade on our old 70 and it performed well.

 

[aaa1950]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

Larry3215 - usually it's 3 or 4 of us old farts that fish together. Glad that us old farts get that opportunity. I have a flag for my boat that says, "Old Guys Rule - Gone Fishing". You should get one.

 

[Larry3215]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

I like that!

 

[aaa1950]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

Check out ********.com - type in flags as the keyword and take a look. They have others made for us old farts, another one I like is "Old Guys Rule, the older I get-the bigger it was". Sorry if I got off track from props, but this flags are just right for water people.

 

[Larry3215]

Re: Need help fine tuning brand new Smoker Craft with Yamaha F115

Thought I would up-date things. After mounting the kicker and the second battery in the back, the boat performs significantly better.

The prop doesnt break loose quite so easily in turns when trimmed out all the way. Top speed went from 34-35 mph at 5500-5600 to 38-39 mph at 5800-5900 depending on conditions.

We may be trying a new prop soon to correct a noise issue. We get a nasty whine between 1000-2000 rpm with the 13.25x17 prop that isnt there with the Yamaha 13x19. Might try a 4 blade but havent decided for sure.