Yamaha sells three 150 horsepower motors with 20" shaft:
(Prices per Ed's Marine)
VMax Carbureted 150...$6,800
VMax HPDI 150............$9,000
F150 (4stroke)............$10,000
Which one would you pick, and why? The hypothetical hull to be powered is a 20' Pathfinder. 20' X 8 1/2' beam X 1250 lbs.
I would rather have the four stroke but it's hard to overlook the price difference, weight, and service issues...
Yamaha 150s
Moderators: bman, Chalk, Tom Keels
Yamaha 150s
Ken
I would ask your mechanic if the added weight of the four stroke is likely to make the boat stern heavy. If it is, then you need to go two stroke. If not, I would buy four stroke. Better mileage, the technology is now proven, and all engines will eventually be fours.
Frankly, I have misgivings these days about the HPDI reliability and technology. When they work, they work great, but too much to go wrong. If you have to go two stroke, I would buy a conventional model. My 115 SWS Yam carb does very well, no problems in 6 years, and about 3-4 mph on a 17 footer.
EJ
Frankly, I have misgivings these days about the HPDI reliability and technology. When they work, they work great, but too much to go wrong. If you have to go two stroke, I would buy a conventional model. My 115 SWS Yam carb does very well, no problems in 6 years, and about 3-4 mph on a 17 footer.
EJ
I believe the carbed model will burn about 10 gallons per hour at 4000 rpms and the four stroke about 6 gallons. At $2.00 a gallon it would take 400 hours to pay the for the $3,200 difference (assuming all the other costs are a wash..)
I feel confident that the new Pathfinder was engineered around the HPDI and the F150.
To me the advantages of the carbureted motor are that it is relatively inexpensive to buy and easy to work on. The downsides are noise, smoke and hard starting in cold weather (Striper fishing in below freezing temps) and the fuel burn.
The advantages of the four stroke are lack of noise and smoke and low fuel burn. The big disadvantage is the price, and that the complexity of it would make it harder to work on (no shade tree mechanics
)
I feel confident that the new Pathfinder was engineered around the HPDI and the F150.
To me the advantages of the carbureted motor are that it is relatively inexpensive to buy and easy to work on. The downsides are noise, smoke and hard starting in cold weather (Striper fishing in below freezing temps) and the fuel burn.
The advantages of the four stroke are lack of noise and smoke and low fuel burn. The big disadvantage is the price, and that the complexity of it would make it harder to work on (no shade tree mechanics
)Ken
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dstockwell
- Posts: 4214
- Joined: March 5th, 2002, 8:00 pm
- Location: Valdosta, GA
First, I don't think the four stroke will come in at 6GPH on that boat.
Second, check the difference in speed at a cruising RPM. The 2 stroke is going to be a little faster. That said, look at MPG rather than GPH. I think you'll find it will take close to 750 hours to make up the difference.
Third, the Yamaha carbed 2 stroke is well proven. It's the most popular motor Yamaha makes for bass boats. If they hold up on bass boats, you'll love it. This is the first year for the 150 HP Yamaha. I don't buy anything the first year it's made.
Ken, maybe I'm old school, but I still like the 2 stroke.
Now, a question. Where did you get the preformance data for a 20 ft. Pathfinder? Last time I liiked, they don't even show the boat on their web site, yet.
Second, check the difference in speed at a cruising RPM. The 2 stroke is going to be a little faster. That said, look at MPG rather than GPH. I think you'll find it will take close to 750 hours to make up the difference.
Third, the Yamaha carbed 2 stroke is well proven. It's the most popular motor Yamaha makes for bass boats. If they hold up on bass boats, you'll love it. This is the first year for the 150 HP Yamaha. I don't buy anything the first year it's made.
Ken, maybe I'm old school, but I still like the 2 stroke.
Now, a question. Where did you get the preformance data for a 20 ft. Pathfinder? Last time I liiked, they don't even show the boat on their web site, yet.
What was I supposed to do today?
TC, Yamaha has a performance bulletin for the 22' Pathfinder with the F150, fuel burn is 6.4 GPH at 4000rpms. To get the 10 GPH I took the average of several boats of similar size that they had bulletins for with the carbed vmax.
Not my numbers, Yamaha's. I don't doubt that all the specs on the performance bulletins are a little too good, but you would think they would be fairly consistant.
The specs on the PF 20 came from a reply by Skip Lyshon on a thread on their bulletin board. They may not be exact but you would have to figure the length, beam and weight are right just based on the specs of the 19 and the 22. I think he also said the MSRP on the 20 is going to be about 3k less than the standard 22'
For what it's worth, it seems like most of the guides I fish with run carbed two strokes.
I think he also said the MSRP on the 20 is going to be about 3k less than the standard 22'
Not my numbers, Yamaha's. I don't doubt that all the specs on the performance bulletins are a little too good, but you would think they would be fairly consistant.
The specs on the PF 20 came from a reply by Skip Lyshon on a thread on their bulletin board. They may not be exact but you would have to figure the length, beam and weight are right just based on the specs of the 19 and the 22. I think he also said the MSRP on the 20 is going to be about 3k less than the standard 22'
For what it's worth, it seems like most of the guides I fish with run carbed two strokes.
I think he also said the MSRP on the 20 is going to be about 3k less than the standard 22'
Ken
HPDI real cost
My 2000 200hp HPDI cost over $2000 in maintenance last year. You must run ring free additive at all times. If the boat isn't used every two weeks you must use fuel stabilizer. The bottom line is in my 120 gallon tank I use $35 of additive and approximately $40 of oil. When added to two dollars per gallon for gas it greatly reduces the cost differential.
Botton line, regular carburated or four cycle. (assuming they don't require all the additives. Don't buy anything without extended warranty which can be price negotiated.
Botton line, regular carburated or four cycle. (assuming they don't require all the additives. Don't buy anything without extended warranty which can be price negotiated.
The F150 actually weighs a couple of pounds less than the 150 hpdi. Only four cylinders but bigger displacement.
If you are interested, check out the performance bulletins for the Parker 21se. They have both the four stroke and HPDI. HPDI had .(point)2 mph more on top speed and .27 seconds faster to plane. Interesting to me is that the one place the HPDIs numbers show a real advantage over the four stroke is fuel economy at anything from a slow cruise to WOT.
If you are interested, check out the performance bulletins for the Parker 21se. They have both the four stroke and HPDI. HPDI had .(point)2 mph more on top speed and .27 seconds faster to plane. Interesting to me is that the one place the HPDIs numbers show a real advantage over the four stroke is fuel economy at anything from a slow cruise to WOT.
Ken
added oil cost
The four stroke has more advantage with todays oil and gas prices. Ran short of oil last Wednesday afternoon and had to pay $20.67 per gallon at Carabelle Marine!