I have a 2002 228G Seafarer powered with a 2002 Yamaha 200 2 stroke I bought last year. Both had 450 hours. The boat is in great shape as is the motor, BUT, at WOT it runs at 4900 RPM and cruises at 25 MPH. I would like it to cruise at 40 or better if possible and WOT should be more like 5500. Should I upgrade the prop to a higher pitch, go to a 4 blade prop, or both?
Prop problems?
- Thread starter jpbyrne1
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We'll need more info. But, first, you're misinformed about props... you would need to go LOWER to raise RPM. But, we can't go to "prop talk" without more info. What size is currently on there? Also, we need to know how you are trimming the engine? For example, if you're not trimming at all (or very little), there's your problem right there. And... has it always done this, or is this a new thing? May need to do a compression check, too. But let's start with those easier questions.
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You won't be cruising at 40 with a 200 on a seafarer...even if it is a 2 stroke. Be lucky to get there at WOT
You'll need less pitch to get your WOT up. 4 blades tend to scrub a bit of top speed/fuel economy but get better hole shot and lower planing speeds. They also give a lot of stern lift and improve low speed dock handling.
With a 4 stroke 225 I do 40 with the curtains up. The 250s seem capable of 45ish top speed, the newest hulls with 300s will hit 50ish. With a 300 a seafarer might do 40 at under 5000 rpm. But only the most recent hulls are rated for 300.
You'll need less pitch to get your WOT up. 4 blades tend to scrub a bit of top speed/fuel economy but get better hole shot and lower planing speeds. They also give a lot of stern lift and improve low speed dock handling.
With a 4 stroke 225 I do 40 with the curtains up. The 250s seem capable of 45ish top speed, the newest hulls with 300s will hit 50ish. With a 300 a seafarer might do 40 at under 5000 rpm. But only the most recent hulls are rated for 300.
I may have the same set up as you, but different model year. Mine is a 2001 228G with a 2001 Yamaha HPDI 200 2-stroke. When I bought the boat a year ago it was improperly prop'd. It had a 4-blade aluminum 15.5" diameter x 19" pitch. Result was slow hole shot and 33 mph top speed at 4400 rpm.
I replaced the prop with a Solas Titan HD 3-blade SS in 14.75" x 17". Now hole shot and top speed are excellent. Only downside to the 3-blade is mid-range cruise with a heavily loaded boat (fuel, water, gear, people) -- the lack of stern lift of a 3-blade means I have to run a bit faster (and more RPMs) to stay on plane.
With your engine, you should aim for WOT RPM of ~5200-5400 for a lightly loaded boat. On flat water my boat will now do 41 mph @ 5200 RPM, properly trimmed out, of course. As others have pointed out, if you keep the engine trimmed all the way down, the boat won't "get up and run". You need to trim up quite a bit once on plane to let the hull do its thing and move easily through the water. Trim back down only to the extent needed to cut through chop or maintain plane at lower speeds/revs.
As others have said, we need some more info to give you specific recommendations. Current prop diameter, pitch, blade count, material (aluminum vs SS), the load you typically carry (# of people, fuel, water, etc.), conditions you usually run in (smooth water, chop & wind, in ocean with swell, etc.), and what you are aiming to optimize (top speed, efficient cruise, or hole shot).
Thanks for your remarks. I don't know the details on the prop yet. I will pull it off after the season and find out. We do use trim correctly and I had the engine looked over prior to putting it in the water for the season and comps were good. There is usually a full (96 gal) tank and four people on board with gear when it tops out at 25 MPH and 4900 WOT. I have not run it alone or with less that 1/2 tank to see how she does but I will. It hasn't been used except for fishing yet. I am thinking about adding the auxilliary tank that will also add 400+ lbs. but I would like to be capable of getting to the deep water, weather permitting.
We won't really be able to help much till we know the prop specifics. Can you just jump in the water or use a skiff or get it close to a dock and tilt it up?
When you say you are trimming it up properly - at WOT, have you trimmed it till your speed no longer increases (good question above about whether it's the boat speed or GPS) or the prop ventilates? The point right before that happens is what we're looking for.
Try it with just yourself.
When you say you are trimming it up properly - at WOT, have you trimmed it till your speed no longer increases (good question above about whether it's the boat speed or GPS) or the prop ventilates? The point right before that happens is what we're looking for.
Try it with just yourself.
Hookup1
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People think more pitch is the answer to more speed. Not always the case. If you can't turn the props the power transfer (prop efficiency) falls way off. I dropped 2" of pitch and went to 4-blade props from www.propgods.com . Amazing difference. I got mid-range performance that I never had and it fits my use-case so much better.
Wot is useless except for gauging how well you are prop'ed. Small boats don't have the waterline length to "use" the speed in anything but perfect conditions. Prop the boat for how you use it.
Wot is useless except for gauging how well you are prop'ed. Small boats don't have the waterline length to "use" the speed in anything but perfect conditions. Prop the boat for how you use it.
Another one of the first things to check is how deep the lower unit is when on plane.
The anti-ventilation plate should be just skimming across the top of the water.
And is the boat slipped? If so what is the condition of the bottom paint and is the bottom clean.
The anti-ventilation plate should be just skimming across the top of the water.
And is the boat slipped? If so what is the condition of the bottom paint and is the bottom clean.
It would also be interesting to know what your definition of "cruise" is. To me, it's a high mid-range speed, that gives me optimal fuel efficiency. Some people don't seem to care how much fuel they burn, as long as they have enough. I have the same hull as you, 92 gallons, hardtop, 225hp OX66. I 'cruise' at 4000rpm/30mph/3mpg, with either the stock 17M Yamaha, or the 17 pitch Powertech OFS4. 40 mph is close to 5000 rpm.
You want to cruise at 40, and get another fuel tank to head off shore, so your priorities are a little conflicting. You will never be able to cruise at 40 in the ocean, in a SF228G with 200 horses, 25 will be a good day, if comfort figures into the definition of cruise.
You want to cruise at 40, and get another fuel tank to head off shore, so your priorities are a little conflicting. You will never be able to cruise at 40 in the ocean, in a SF228G with 200 horses, 25 will be a good day, if comfort figures into the definition of cruise.
I pulled the prop and its a 13 3/4 X 17 M2 SS 15 spline. This was the first season we had the boat and it runs 25 - 26 with WOT at 4900 RPM. The boat weighs about 4500# full with gear and crew. We do use the trim to get max speed when cruising. I dont think it has enough power but if I can change propsxto squeeze out better performane I will save a bundle over upgrading to a 250.
How are you measuring speed? GPS = accurate, Yamaha dash gauge = a wild guess that could be very low if the pickup tube is partly clogged.
Dash and gps are within a couple mph all the time. Also, wot maxes at 4900 and the book says 5400 to 5800. Im thinking about moving pitch down to 15 and maybe a bump to 14.5" SS.
If your numbers are correct, your current prop is slipping badly -- that is, not getting a good bite in the water. Assuming your engine is healthy, you should be seeing upper 30's at 4900 rpm. I think your current prop is too small in diameter, too large in pitch, and doesn't have enough blade surface area. If you go to a 15" pitch, you should do a 4 blade prop to get more surface area and also go with an increased diameter of 14.75 - 15.25".
The diameter is definitely small. Like mentioned, closer to 15-1/4 should be correct. If you drop pitch, your RPM will go up - but that doesn't seem like the proper thing to do and it would really be a band-aid fix. I think there's another variable still at play here. A 4-blade won't hurt - but for the same reason, we need to figure out the issue, first. How clean is the hull bottom? Have you checked compression? Is the prop "perfect"?
Did it always do this?
And, you're positive you're trimming up as far as you can go till ventilation or no more speed increase?
Anyone else with a similar boat and 200HP AND running a 3-blade? What pitch are you using? Going to 15" just doesn't seem right.
Did it always do this?
And, you're positive you're trimming up as far as you can go till ventilation or no more speed increase?
Anyone else with a similar boat and 200HP AND running a 3-blade? What pitch are you using? Going to 15" just doesn't seem right.
Thanks for all the advice. I finally upgraded the prop to a Solas SS 15.6" with 13 pitch 3 blade and it really makes a difference. Now I can get wot of 5300 and tops out at 40 MPH. I'm hoping to cruise at 30 and maximize fuel efficiency when possible. We haven't had her out with full fuel, 4 guys and all the rest but I'm sure it will be better.
If your engine is an HDPS with the 1.86 lower unit ratio, then you are doing very well with only 14% slip.