Propeller Performance
- Thread starter Halilogger
- Start date
Halilogger
Active Member
I've never been not able to get on plane, only once when I was really loaded it took a little longer out of the hole.
I have 2003 block and it's a Yamaha,with Mercury label, I was told the only 4 stroke that is made by Mercury is the Verado, any thing else is Yamaha or Suzuki.
I have 2003 block and it's a Yamaha,with Mercury label, I was told the only 4 stroke that is made by Mercury is the Verado, any thing else is Yamaha or Suzuki.
The 2003 vintage Yami's have the corrosion issue which doesn't kill the engine but is a costly repair. It commonly appears after about 700 hours. There is nothing you can do to prevent it, fresh water flushing doesn't help. The weakest parts of the actual engine are the pistons. Yamaha uses cast pistons over forged. This goes well back into their older 2 strokes as well. The vast majority of early engine failures I've heard about are piston/ring related. My own personal engines included. I now rebuild with US made forged Wisco pistons.
I would say if you get over 1000 hrs without spending serious money, you are in the minority.
I would say if you get over 1000 hrs without spending serious money, you are in the minority.
Halilogger
Active Member
I heard the corrosion issues were zinc related, internal engine zincs were to hard. So what are my options if I have no control over this problem. Rebuild, how much? or a new motor.
The corrosion in the exhaust housing which causes the engine to loose power because it falls out of tune...and the ecm can't compensate that much for it. The cause is a wet cooled exhaust (salt water in your case) combined with heat and acid exhaust gases. The combo over time eats away the housing. There is also an issue with the heads, but was told that might be more of a factory casting flaw over the zincs.
spring fever
Well-Known Member
I'm going through this agony right now with my 2003 yammi 225. Got me wanting to trade in for a 300-but no money!! I can get 5K on trade-the motor is running beautifully-so what to do? The knowledge is like a cancer eating at your brain. I believe profisher said you can get it scoped which only requires a leg removal but then that's a 500 dollar bill -not huge but when the motor is only worth 4-5 K something to think on. I have changed the head zincs and will switch to salt away flushes and check the oil for water after every trip (do anyway) and run it. A fix if the head is not involved is in the 3-4K bracket-then that is decision time-guess this takes me out of the running for Tuna fisherman of the year-but I guess more than that it makes me very uncertain as to why I should ever entertain the thought of buying another Yamaha
"So many fish-So little Time"
TheBigGuy
Well-Known Member
Sorry to drag this off topic [8D] but I thought I'd give a little prop selection info.
The following are quotes I've collected from other sites regarding how to select the right prop for your boat. I hope the info helps a few people interested in re-propping.
So put a good tune on the motor, clean the bottom and do a WOT run with your usual anticipated load. Compare your numbers with the recommended WOT range in your engine manual and pitch up or down from there. As a rule, going up a pitch will drop RPM by 200, going down will increase them. Going from aluminum to stainless will increase RPM by 100 or so, so whether you are at the top or bottom of the recommended range will dictate which stainless to try.
you want to achieve your engines WOT RPM range no matter what prop you use.
4 blades also usually reduce max rpm, compared to a similar 3 blade.
3 blades to 4 go down 1 inch in pitch, and 4 to 3 go up 1 inch pitch.
A 4 blade will help the boat plane easier and stay on plane with less power
When changing props to a 4 blade typically you drop a pitch or two from what is right for a three blade prop.
Generally speaking, you will pick up some RPM just going from a 4 to a three blade with no pitch change.
As a normal course of events if you have an aluminum 3 blade prop on your boat you can expect about a 200 to 300 drop in RPM, changing pitch for pitch to a 4 blade SS.
In general, an un-cupped prop of a given pitch will act close to a cupped prop of 2" less pitch- RPM wise. An un-cupped prop tends to be used on stern-heavy boats and is likely an older design.
While it might be true dropping diameter will raise RPM's it also lowers the prop's drag and load on the motor. Also lowers the props thrust and acceleration.
Generally when going up in diameter you lose RPM unless you are
willing to raise the engine to get the Rpm back and lose some drag..this is maximizing the set-up. Smaller diameter in a given pitch is used mostly on non-surfacing applications, and tends to be (in most cases) a bit slower, except for very light boats, where you find small dia. and
large pitch
Going from 4 blade to 3 blade and adding 1 inch of pitch should give you roughly the same RPM. (Drop 200RPM for the 1 inch pitch increase and add 200RPM for the drop from 4 to 3 blades).
When converting to a five blade, it has been our experience that dropping one or two degrees in pitch is recommended due to the exceptionally high efficiently of the extra blade.
If you can use 100% of the trim range without venting then generally speaking the motor height is still too low for that prop
Simple rule to props is: Load the boat with the same weight you intend to on (average weight) full fuel and water, warm it up and slowly bring it up to max rpm, if you reach max rpm + then you can decide if you need more pitch-cup the prop, or if you cannot reach max rpm then you can adjust the pitch down. After testing, if the prop needs adjusting, go online and Google Michigain Wheel, fill out the prop-it form and you will get expert advice.
The following are quotes I've collected from other sites regarding how to select the right prop for your boat. I hope the info helps a few people interested in re-propping.
So put a good tune on the motor, clean the bottom and do a WOT run with your usual anticipated load. Compare your numbers with the recommended WOT range in your engine manual and pitch up or down from there. As a rule, going up a pitch will drop RPM by 200, going down will increase them. Going from aluminum to stainless will increase RPM by 100 or so, so whether you are at the top or bottom of the recommended range will dictate which stainless to try.
you want to achieve your engines WOT RPM range no matter what prop you use.
4 blades also usually reduce max rpm, compared to a similar 3 blade.
3 blades to 4 go down 1 inch in pitch, and 4 to 3 go up 1 inch pitch.
A 4 blade will help the boat plane easier and stay on plane with less power
When changing props to a 4 blade typically you drop a pitch or two from what is right for a three blade prop.
Generally speaking, you will pick up some RPM just going from a 4 to a three blade with no pitch change.
As a normal course of events if you have an aluminum 3 blade prop on your boat you can expect about a 200 to 300 drop in RPM, changing pitch for pitch to a 4 blade SS.
In general, an un-cupped prop of a given pitch will act close to a cupped prop of 2" less pitch- RPM wise. An un-cupped prop tends to be used on stern-heavy boats and is likely an older design.
While it might be true dropping diameter will raise RPM's it also lowers the prop's drag and load on the motor. Also lowers the props thrust and acceleration.
Generally when going up in diameter you lose RPM unless you are
willing to raise the engine to get the Rpm back and lose some drag..this is maximizing the set-up. Smaller diameter in a given pitch is used mostly on non-surfacing applications, and tends to be (in most cases) a bit slower, except for very light boats, where you find small dia. and
large pitch
Going from 4 blade to 3 blade and adding 1 inch of pitch should give you roughly the same RPM. (Drop 200RPM for the 1 inch pitch increase and add 200RPM for the drop from 4 to 3 blades).
When converting to a five blade, it has been our experience that dropping one or two degrees in pitch is recommended due to the exceptionally high efficiently of the extra blade.
If you can use 100% of the trim range without venting then generally speaking the motor height is still too low for that prop
Simple rule to props is: Load the boat with the same weight you intend to on (average weight) full fuel and water, warm it up and slowly bring it up to max rpm, if you reach max rpm + then you can decide if you need more pitch-cup the prop, or if you cannot reach max rpm then you can adjust the pitch down. After testing, if the prop needs adjusting, go online and Google Michigain Wheel, fill out the prop-it form and you will get expert advice.
Charlie
Well-Known Member
I wouldn't run out any switch anything, yet?quote:Originally posted by spring fever
I'm going through this agony right now with my 2003 yammi 225. Got me wanting to trade in for a 300-but no money!! I can get 5K on trade-the motor is running beautifully-so what to do? The knowledge is like a cancer eating at your brain. I believe profisher said you can get it scoped which only requires a leg removal but then that's a 500 dollar bill -not huge but when the motor is only worth 4-5 K something to think on. I have changed the head zincs and will switch to salt away flushes and check the oil for water after every trip (do anyway) and run it. A fix if the head is not involved is in the 3-4K bracket-then that is decision time-guess this takes me out of the running for Tuna fisherman of the year-but I guess more than that it makes me very uncertain as to why I should ever entertain the thought of buying another Yamaha
"So many fish-So little Time"
I actually own two (2) of them and I can't say anything, except they are probably the best engines I have had. I really don’t know of any marine engine that doesn’t have some sort of an issue?
On these particular engines (Yamaha), it appears to be exhaust plates, manifolds and exhaust tubes. Since I do have twin 2003 Mercury Saltwater series, I decided to do some research. I found it interesting that whatever seems to come up always refers back to the Yamaha... and there isn’t much on the Mercury’s made by Yamaha and I am not sure if Mercury even used Yamaha's exhaust - I haven’t found that (yet). Mercury did use Yamaha power heads, but if Mercury specifications were different for the exhaust system, it may not even be an issue on Mercury? However, I have found given time all motors are susceptible to this… and ALL are subject and will fail, there is nothing the casual user can do to prevent it on any engine.
As far as I can find, this corrosion issue seems to be more with the first generation Yamaha V6's, two star emissions certified (check the sticker on the engine). The three star V6's had an additive paint or coating which helps solve the problem from what little I know. Then I am finding, not all Two Star V6's have this problem - but time will tell as they age.
According to what I can find, Yamaha (which I have not personally contacted) simply says, "Flush your engine after every use in salt water", but since this seems to be on the dry side of the exhaust, I personally don’t believe that and the flush system doesn’t even flush the internal parts of the engine? You would have to use rabbit ears to flush the internal parts of the engine.
You have to remember there are thousands of F225's out there and they all aren't failing due to corroded exhaust manifolds. Agreeably, 2003 F225's and earlier ones are more exposed to salt water corrosion (the 2004 and above models have better paint and coatings).
No need to fret about it. Use the thing and if you experience overheat conditions NOT related to poppit valves(aka PCV) , thermostats or water pumps - then you (and I ) will cross that bridge when we come to it.
I will take this issue over a lot of others; including, the electrolysis problems of the Bravo III has! That one can really be a big, expensive nightmare – been there!
spring fever
Well-Known Member
Amen and thanks for the ray of sunshine Charlie-I have to believe in something and I believe I'll have a beer and leave the topic on a good note!!!
"So many fish-So little Time"
Halilogger
Active Member
Yes that is a bit of relief, My boat was 6 years old when I purchased it, and it had only 36hrs on it, and now has 210hrs. I'm hoping i can get another 3 to 4 years with nothing major going. I will stay true to my maintenance schedule and hope for the best.
My buddy Yami mechanic says they see it being an issue any time after about 700 hrs. It seems to be that much combination of heat, salt water and acidic exhaust gases that is required to eat away at the parts in question. Don't forget, the VAST majority of outboards see way less hrs each year than we on the west coast put on them. In a good season I'll put 200 hrs a season on the main, the last few years more like 150 tops. The average guy on the west coast less than 100, the average user anywhere else about 50 hrs a year. So for the vast majority of engines out there that is 14 years to have the issue show up. Most will have sold the boat or had other problems before then.
TheBigGuy
Well-Known Member
I have been running a relatively high end Mercury Trophy Plus 17P stainless four blade on my 115 four stroke Merc. My boat is a Harbercraft aluminum 18 footer. After reading many posts on various boating forums I came to the conclusion that a prop change was in order. It speced out OK at 5800 rpm at 43mph, the motors red line is 6000 rpm. This is the prop Mercury recommends for this motor. However, once traveling over 30 mph the boat began to porpoise and was downright scary at top speed. The only way to stop the porpoising was to trim the motor fully in. Traveling fully trimmed in reduces speed and efficiency, and the ride was still scary. So, I set about trying to improve the boats performance.
After reading many posts I decided to try a prop that provides more stern lift. The Trophy + stainless prop is a bow lifting prop. So I thought I'd start with an aluminum prop to experiment with alternatives because of the lower cost. I picked up a Solas Rubex 3 blade aluminum 17P to test. The Solas Amita/Rubex props seemed to have a very good reputation for a relatively cheap prop. They are reputed to provide a good amount of stern lift, so I thought they'd be a good place to start. They are compatible with the Mercury Flow Torq II interchangable hub kit that came with the Trophy + prop already on the boat. This hub kit makes the prop interchangeable with many motors and other props in the same size range.
After installing the prop I took it for a test run. I was totally taken by surprise as to how well this 3 blade aluminum prop performed. I was used to a jarringly harsh ride with the Trophy prop in any type of chop (no matter how I trimmed the motor). The attitude of the hull was very different traveling with this new prop. The bow seemed to cut the waves far more easily, rather than slamming up and down in the slop. Top speed and rpms were the same as the old prop, but with one more passenger aboard. The porpoising at top speed was almost eliminated, but the ride was still a little scary when full out. All in all, a very successful test for a sub one hundred dollar prop.
I have a four blade 17P Solas Rubex on order for the next trial to see how they compare. I would probably prefer to go with the four blade, but the three blade was so cheap I thought I'd try it first. The next thing I am going to try is raising the outboard a hole or two on the transom with the four blade. That hopefully will result in improved top speed and help to eliminate the porpoising.
If those changes haven't completely solved the ride issues I may try a stabilizing hydrofoil on the AV plate. I'll report back with the new results when the 4 blade arrives.
After reading many posts I decided to try a prop that provides more stern lift. The Trophy + stainless prop is a bow lifting prop. So I thought I'd start with an aluminum prop to experiment with alternatives because of the lower cost. I picked up a Solas Rubex 3 blade aluminum 17P to test. The Solas Amita/Rubex props seemed to have a very good reputation for a relatively cheap prop. They are reputed to provide a good amount of stern lift, so I thought they'd be a good place to start. They are compatible with the Mercury Flow Torq II interchangable hub kit that came with the Trophy + prop already on the boat. This hub kit makes the prop interchangeable with many motors and other props in the same size range.
After installing the prop I took it for a test run. I was totally taken by surprise as to how well this 3 blade aluminum prop performed. I was used to a jarringly harsh ride with the Trophy prop in any type of chop (no matter how I trimmed the motor). The attitude of the hull was very different traveling with this new prop. The bow seemed to cut the waves far more easily, rather than slamming up and down in the slop. Top speed and rpms were the same as the old prop, but with one more passenger aboard. The porpoising at top speed was almost eliminated, but the ride was still a little scary when full out. All in all, a very successful test for a sub one hundred dollar prop.
I have a four blade 17P Solas Rubex on order for the next trial to see how they compare. I would probably prefer to go with the four blade, but the three blade was so cheap I thought I'd try it first. The next thing I am going to try is raising the outboard a hole or two on the transom with the four blade. That hopefully will result in improved top speed and help to eliminate the porpoising.
If those changes haven't completely solved the ride issues I may try a stabilizing hydrofoil on the AV plate. I'll report back with the new results when the 4 blade arrives.
Doug
Well-Known Member
Spring Fever
I see you run the same boat as I do (skagit 24)
I just change my engine from a f250 Yamaha to the new 300 Yamaha (6cyl) I opted for the new SDS prop. The boat went in for new engines and a hull paint job last week so I don't know how they will perform yet but the with the 250 and a SS salt water 2 it was great out of the hole and tops speed was 40+. I don't know the pitch
I haven't heard too much about the new SDS props so I'm hoping it will outperform my SS salt water 2 which was on my 250.
I see you run the same boat as I do (skagit 24)
I just change my engine from a f250 Yamaha to the new 300 Yamaha (6cyl) I opted for the new SDS prop. The boat went in for new engines and a hull paint job last week so I don't know how they will perform yet but the with the 250 and a SS salt water 2 it was great out of the hole and tops speed was 40+. I don't know the pitch
I haven't heard too much about the new SDS props so I'm hoping it will outperform my SS salt water 2 which was on my 250.
spring fever
Well-Known Member
Doug I have been running the 225 yammi and with all the "large people" myself included there are times it is slow out of the hole. I have done a serious weight reduction scheme on the boat(not on me) and hope this might help somewhat. I would be really interested in your performance on the 300 and if you don't feel like starting a thread please feel free to drop me a PM
Doug
Well-Known Member
The new 6 cyl 300 is 50 lb less weight and 50hp more than the 250 hp, so I'm hoping it gives me better cruising gas mileage . Yamaha notes the new 300 gets the best cruising mileage of any 300 hp on the market.
My old 250 Yamaha had the fuel management system and the best I could get was 2.3 miles per gallon and the worst 23 gallon per hour at 5800 rpms. I'm hoping to improve.
From what I've read about the SDS prop is that it will stop the clunking in and out of gear and everything else will remains the same. My 250 had a SS salt water 2 prop which could have gone on the 300 but if your going with new tech I felt I better get everything new.
I'm TC approved to carry a max. of 7 (incl myself) which I do carry some days and the only time I had a problem with getting out of the hole was if people were on the back deck and I had lots of fuel. My 250 was great until the pinion gear snapped.
Once I get the boat back in the water, I will keep you posted on the 300 performance.
My old 250 Yamaha had the fuel management system and the best I could get was 2.3 miles per gallon and the worst 23 gallon per hour at 5800 rpms. I'm hoping to improve.
From what I've read about the SDS prop is that it will stop the clunking in and out of gear and everything else will remains the same. My 250 had a SS salt water 2 prop which could have gone on the 300 but if your going with new tech I felt I better get everything new.
I'm TC approved to carry a max. of 7 (incl myself) which I do carry some days and the only time I had a problem with getting out of the hole was if people were on the back deck and I had lots of fuel. My 250 was great until the pinion gear snapped.
Once I get the boat back in the water, I will keep you posted on the 300 performance.
spring fever
Well-Known Member
Thanks for that Doug-look forward to seeing it and hope it lives up to your expectations
Halilogger
Active Member
I was debating when I re power, to maybe try the Verado, I've talked to 2 guys with them and they love them.
TheBigGuy
Well-Known Member
Solas Rubex 17P four blade aluminum prop arrived today. I can hardly wait to try it out. Is anyone else using the Solas Amita or Rubex props? What are your impressions of the Solas propellers from anyone who's tried them. They seem to be a very good value both in aluminum and stainless.
I was looking for a prop with a fair bit of stern lift. Has anyone tried another prop that has good stern lift for the intermediate size outboards (mine is a 115 merc). Any stainless or aluminum recomendations appreciated.
I was looking for a prop with a fair bit of stern lift. Has anyone tried another prop that has good stern lift for the intermediate size outboards (mine is a 115 merc). Any stainless or aluminum recomendations appreciated.
Halilogger
Active Member
Hi Bigguy that was the issue I had with my little 18' Legend. I had a 4 stroke 115 Merc , with 17 pitch vengence stainless and I can say that prop didn't have much stern lift.
I've looked on line and seen those props, be intresting to hear feed back on them.
I've looked on line and seen those props, be intresting to hear feed back on them.
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