*THE HULL TRUTH is the world's largest FREE network for the discussion of Boating & Fishing. Whether you're researching a new boat, or are a seasoned Captain, you'll find The Hull Truth Boating & Fishing Message Forum contains a wealth of information from Boaters and Sportfishermen around the world.
Welcome to the updated THT!
If you are having trouble signing in, please email feedback@thehulltruth.com with your username and we will help you. We thank you for your patience as we help you access the new site!
Random Quote: Give a man a fish, feed him once.... teach a man to fish, feed him for life!
I would be real careful making any statements about the new 150 4str. My understanding it is a 4cyl that is why it is so light. That sure is wringing a lot of horsepower out of a 4cyl.
hyefly
Careful we got incomming!!!!!!!
You are probobly sitting in a ringside seat for the infamous and never ending 2str-4str battle.
I purchased a 4str and matter of fact I did speak to the boat builder in person. One of the most important questions I asked was the wieght question. And on my particular boat it made no difference as for the way the boat handled the wieght. Course maybe my little old Capehorn might be overbuilt a tad but I like it that way. Falls off plane when throttled back, nope ain't had that problem either. Course if it did maybe it ain't a torque question, it might be a prop question.
Gas mileage never entered into my thoughts, boat has a 42 gallon tank, with any outboard I don't think I could run it enough to use it all up in a day. Buying the gas? Hell, I bought a boat, if I was going to worry about cost I guess I should have bought a savings bond. The HPDIs may get better mileage but by the time you factor in the oil your burning a fill up might cost a little more. Course with a 4str I ain't burning oil, I am changing it every 100 hours. A boat is going to take so much money no matter what, if it don't get you one way it will get you the other.
quote:Originally posted by zup:
The 4-stroke 150 is actually lighter than the HPDI, this is likely since it is Yamahas newest design and they learned how to trim the fat. If this is in fact due to new designs it will find its way into the 200 and 225 4-stroke in the next model year or two.
Mike
So, this "NEW" technology, is gonna reduce the weight of the 225/4 HUH? How big of a FOUR CYLINDER is it going to have to be to produce 225Hp? The reason the F150 is so light is it is a 2.7L FOUR cylinder vs a 2.6L SIX cylinder for the 150HPDI. If you cut off 1/3 of the motor it is bound to be lighter.
William
1900CC Key West W/ 115 Yammie 4 stroke
Biggest boat that would fit in my garage!
To answer the hp delima remember BIA allows motor manf. to 10% either way. Most 2stks are at the top 10% of the scale,ie 115 is really
dyno prop hp 125. The NEW 4STS are more difficult to make HP so they are @ the bottom 10% 115 4stk may be 110 hp or 105 hp. this could be 15 to20 real hp less. HP is HP but the decal on the motor is not the true rating.
Ask a local dealer with a dyno. The closees to decal hp 140suzuki-115 yammy-merc. most othr 4-stroke are on the bottom end of the BIA stds.
I had two four strokes, a 50 and 90 mercury. Now I have a 150 Yamaha hpdi. The four strokes are very quiet at idle, no smoke and great on gas. The 2 stoke is almost as quiet at idle and has a better power curve, It's better off the line and hold plane at lower speeds better. I troll alot with my big motor and the smell of the smoke is bothersome. There is no visible smoke from the 2s but I am going to buy a small 4s for trolling.
The reason the F150 is so light is it is a 2.7L FOUR cylinder vs a 2.6L SIX cylinder for the 150HPDI. If you cut off 1/3 of the motor it is bound to be lighter.
William
1900CC Key West W/ 115 Yammie 4 stroke
Biggest boat that would fit in my garage!
I am not really sure how 2.7 liters is 1/3 of 2.6 liters but I will take you word for it.
i believe he is refering to the number of cylinders...
As far as wringing 150 hp out of a 4 cylinder.. so what ... it has the displacement of the mid range v-6's.....lots of 4 cyl 4-stroke motors in the automotive world producing much more than 150 hp..... only time will tell of course with any new series of motors.... but if i was a betting man....
quote:Originally posted by big bite:
If torque is the reason fo rselecting 2 stroke over a 4 then there shouldn't be an issue. You WILL NOT relize the difference. If you think you will, get a 2 stroke and do like all the others that see and DONT hear my four stroke, just sahke your head. Also when you are "trying " to fill oil resevior and not make a mess, think of the four stroke. When you start you motor and the smoke rolls in your eyes , think of the four stroke. But al lest you WILL know when the moter is running.
TIGHT LINES!!
Do you think of 2's when changing your oil every 100 hours. Not too easy when the boat's docked in the water. How about when changing those timing belts?
As for smoke, show me a ficht or hpdi that smokes.
I agree with ZUP. I think that my engines broke in real well, and have plenty of mid range torque. Especially for larger hulls (25 +) with twins, you cant beat the four strokes in economy, quietness, etc. etc. etc. At 100 hrs 821 gals, you do the math. "Just Get Em" You will never look back.
quote:Originally posted by John957:
quote:Originally posted by big bite:
If torque is the reason fo rselecting 2 stroke over a 4 then there shouldn't be an issue. You WILL NOT relize the difference. If you think you will, get a 2 stroke and do like all the others that see and DONT hear my four stroke, just sahke your head. Also when you are "trying " to fill oil resevior and not make a mess, think of the four stroke. When you start you motor and the smoke rolls in your eyes , think of the four stroke. But al lest you WILL know when the moter is running.
TIGHT LINES!!
Do you think of 2's when changing your oil every 100 hours. Not too easy when the boat's docked in the water. How about when changing those timing belts?
As for smoke, show me a ficht or hpdi that smokes.
You change the Motor oil the same way you change your lower unit oil. Drain out old oil and fill with new. The filters can be changed waterborne and if you have a pump like you would use for an inboard, you can change the motor oil waterborne in 10 minutes with no problems. You still have to haul the boat for the lower unit.
You are also right, a FICHT, HPDI nor Optibomb smokes but they still SMELL like it is smoking you just can't see it.
William
1900CC Key West W/ 115 Yammie 4 stroke
Biggest boat that would fit in my garage!
The fact is that both the 2-stroke HPDI engines and the 4-stroke engines are excellent choices. They are both quiet, clean and efficient. Are the 4-strokes heavier than the 2-strokes, generally yes (particularly the Honda’s).
Despite all the claims to the contrary when you add up the cost of the 2-stroke oil that is used and the factory recommended maintenance for the HPDI it would likely be equivalent to the cost of oil changes and routine maintenance for a 4-stroke.
If I were buying a motor for a bass boat, flats boat, bayboat or performance boat it would be an HPDI, no question. For an offshore boat or a cruiser I would, and have, bought a 4-stroke.
I have a 23’ Seacraft with a 225 Honda. The boat will pull up two skiers (did it last weekend at Kerr Dam), troll all day without a hiccup, and get the boat up on a plane as fast than my 23’ Wahoo with a 225 carbureted Merc. But if I decided to re-power my 22’ pathfinder a 225 HPDI Yamaha V-Max would top the list.
The fact is there are different strokes for different folks (sorry could not resist).
Let’s find some common ground; boy do those carbureted 2-strokes suck or what?
I agree with zup. The way the boat is used will greatly influence the two-stroke/four-stroke decision.
My next boat will probably have big four-strokes (250 or 300 HP) because I will cruise long distances as well as fish. Carrying two stroke oil will become a burden at that point, and I wouldn't want to rely on being able to get the correct oil at a distant fuel dock, or have to search for a fuel dock that carries the correct oil.
If I were to buy a boat for local backwater fishing (which I recently did), I would buy a carbed two-stroke because I can buy oil, store it at home, and take what I need with me to fill-up when I get fuel, and I cannot possibly use enough fuel in a lifetime to make up the price difference.
If I were buying a boat to fish offshore, but not cruise, I would buy a DFI two-stroke because I do not think there is a big difference in maintenance or cost between DFI and four-stroke, and carrying an oil would not be an issue since I would be returning to my home dock after each day.
I agree with zup and sailfish above. It depends on how you use your boat. I may be wrong, but I don't remember you saying what type of boat you were getting, how often you would be using it, what distances and mileage, etc. To me, that is the big part of the equation. Both 2 and 4 have their place. It depends on usage.
Lets pick on sailboaters.What other loser would put a 10 hp motor on a 25' boat?
Sorry cc13, I was just kidding, but you make an excellent point. There were a bunch of sailboats coming in a narrow extremely busy inlet this weekend under sail, tacking here and there; I wish I had installed that old Navy surplus torpedo tube. The only good sailboat is a sunken sailboat (They make excellent high profile reefs).
Sorry - a little off topic but I couldn't resist the invitation to pick on the blowboaters...
What the first thing a sale boter does after he purchases his new bote?
Line up a potential list of suckers he can invite on his bote and boss around while he tries to look like Cap'n Bly holding the round thingy at the back.
What should a power boater do as he approaches to overtake a sale bote in a narrow channel?
Carefully line up the angle at which he passes so that the trough of his wake is parallel with the keel of the sale bote, pass, wave, smile, and watch the mast sway back and forth as you look over your shoulder.
Why does a sale boter always have a frown on his face?
That dang tiller got rammed up his a$$ the last time you passed him stupid!
I have also owned both 2 strokes and 4 strokes from different manufactures. My first 4 banger was a Honda 90. I could not believe how quiet it was, how strong it was, and how fuel efficient it was. On the same boat, same weight, I had the 90, my buddy had a 130 2 stroke. Same prop as well. I planed quicker than he did, ran the same speed, but burned half the gas and I did not need to add oil. I sold that boat last year, logged 250 + hours in 4.5 years, no problems. I now am the happy owner of a Yamaha F200. Even quieter than the Honda, and you better hold on to something before I slam it down. Really good on gas and environmentally friendly as well. In a nutshell, 4 strokes cost more up front, but they cost less to own because of the fuel economy and because it cost less to service them every year. They are also somewhat over-engineered for marine use which makes them more robust and reliable. On the down side, 4 strokes are inherently heavier than 2 stokes and have more moving parts. 2 stroke technology continues to improve, but I will stick with my quick starting, quiet running, quick planning, no smell, no smoke, easy maintenance 4 banger.
I'm not super familiar other than theories of engine opperation and have a question. I understand the fours have valves and timing belt, chain, or gear and the twos don't.
Do the fours really have more parts than an Opti, HPDI, or FICHT?
With all the additional fuel/oil injection
it seems like the two strokes might be catching up with the number of parts. I'm interested if anyone has the answer.
4 Stroke v. 2 Stroke, midrange torque and ride... 
