Had a great time with the maiden voyage on my 1993 208 adventure. Launch and retrieval went pretty smooth. I took her to a local lake to test things out. The only thing that seemed unusual was that at cruise around 3800 rpms my Garmin GPS was only showing 18.5 knots ? Boat is powered with a Johnson 200 2 stroke, no hard top,bottom paint, full tank of gas, tabs fully retracted and glass conditions. I thought my cruise speed would be much higher? Motor runs strong while on plane. Is there something I'm missing here or does the speed sound about right? At 6000 rpms GPS showed 32.5 knots.Any thoughts? Thanks.
First day on the water w 208, cruise speed off ?
- Thread starter Socalinsd1
- Start date
Perhaps it is the prop? Could be wrong pitch or it could be made of aluminum? Since I boat a fair amount in Florida my gps is set to mph. Why? Because manatee speed zones are in mph and not knots. I had a 192 it topped out at 44 mph with a 150 4 stroke. My 228 tops out around 43. Your boat should be in the same neighborhood as well. I think it is under propped meaning the pitch is too shallow or the diameter is smaller than it should be. If the prop is aluminum it will flex under load and you will lose some speed as a result.
Socalinsd1 said:
Your top end is in line with what I would expect. That hull is noticeably affected by a full tank of fuel which is the same as having 3 or 4 people on board with a quarter of a tank.
The trim of the motor is important also, play with it. Assuming you don't use a tank a trip, it will save you money and add performance to not add more fuel than you will use in an outing or two plus a reserve
Parthery
GreatGrady Captain
You are a little low...
My 99 208 with a 200 Yamaha ran 43 mph at 5500 rpm. Was turning a SS 17" pitch prop.
I'm assuming you trimmed it out?
You might need to play with prop selection....
My 99 208 with a 200 Yamaha ran 43 mph at 5500 rpm. Was turning a SS 17" pitch prop.
I'm assuming you trimmed it out?
You might need to play with prop selection....
Congrats on the new boat.
If I recall 6000 is the maximum rpm for that outboard, and ideally you want to be able to hit the max with an average load. It sounds like you might have a lot of slip with your propeller, what is the diameter and what pitch? Is it aluminum or stainless? Assuming your bottom paint is smooth I would think your top end and your cruise speed will go up a few mph with the right stainless steel prop with the boat trimmed out perfectly. Did you adjust the motor trim to get the best performance (typically raise trim all the way and lower slightly to prevent slip)?
If I recall 6000 is the maximum rpm for that outboard, and ideally you want to be able to hit the max with an average load. It sounds like you might have a lot of slip with your propeller, what is the diameter and what pitch? Is it aluminum or stainless? Assuming your bottom paint is smooth I would think your top end and your cruise speed will go up a few mph with the right stainless steel prop with the boat trimmed out perfectly. Did you adjust the motor trim to get the best performance (typically raise trim all the way and lower slightly to prevent slip)?
Thanks for the tips, I will go and measure the prop, I think i s stainless steel. As far as the trim goes excuse my ignorance since this is my first boat. I just trimmed it all the way down, are you saying that I should bring it up some and if so how much typically? With a full tank that's another 550 lbs or so but still seems real like a very low cruise for that motor.
if I understand correctly, with the trim all the way down your going to be pushing the bow down, which in turns plows more water...what your looking for is the sweet spot in the middle where your up on plain and riding ontop of waves, to much or high and your going to start to porpoise. You will notice a big difference. The tabs are there to help you out and will allow you to adjust to sea conditions. If you think your in the sweet spot RPMS like the above posters should be in the sweet spot too, if not your prop will need to be changed.
In calm water You Would Raise The Engine (Trim Up) Which Will Also Raise The Bow Of The Boat. As A Result, You Will Have Less Of The Boat In The Water And Your Speed Will Increase. You Will Also Reduce Your Fuel Consumption At The Same time.
By Not Raising Your Bow, It's Kind Of Like Driving A Car With Your Foot On The Gas And The Brake At The Same Time.
Keep In Mind, You Will Want To Lower Your Bow When The Seas Get Large.
Sorry For The Odd Typing, On My Phone.
By Not Raising Your Bow, It's Kind Of Like Driving A Car With Your Foot On The Gas And The Brake At The Same Time.
Keep In Mind, You Will Want To Lower Your Bow When The Seas Get Large.
Sorry For The Odd Typing, On My Phone.
Pick a RPM range that is typical for your cruise speed. Let's pick 4200 rpm as an example. In relatively calm water at that engine revs, note your speed using GPS. Now raise the motor (trim up) ever so little at a time and watch the speed. It will increase as the bow raises and resistance is lessened. At some point, the speed may actually lower or you may experience some cavitation or loss of steering stability. At that point you have passed the sweet spot, so trim down a bit. After a while you will be able to feel how the trim is and adjust without looking at the trim indicator.
The optimal trim depends to a great extent on water conditions. You have to play and learn.
Don't overly discount the effect of a full tank. 500 pounds of fuel is a big load on a hull that weights under 3,000 pounds. I am talking from experience on a 208. A full oad makes a lot of difference on performance, especially time to plane.
The optimal trim depends to a great extent on water conditions. You have to play and learn.
Don't overly discount the effect of a full tank. 500 pounds of fuel is a big load on a hull that weights under 3,000 pounds. I am talking from experience on a 208. A full oad makes a lot of difference on performance, especially time to plane.
It's the trim! Full down to get on plane. Once on plane, start bumping up the trim. You'll feel the boat accelerate and rpm might even rise when you get it right. Too much and the prop will cavitate and rev in which case you bump the trim down.
The tabs are mostly to level the boat while underway. Start with them both up. Then push the one down as needed to level the boat. Everytime you change course, you'll need to adjust the tabs to adjust to the wind and waves changing in relation to your boat.
Most boaters use MPH. KTS for sailboat and ships.
The tabs are mostly to level the boat while underway. Start with them both up. Then push the one down as needed to level the boat. Everytime you change course, you'll need to adjust the tabs to adjust to the wind and waves changing in relation to your boat.
Most boaters use MPH. KTS for sailboat and ships.
I did fuel testing with a T-22 and 225 four stroke. Without a doubt, motor trim had the greatest affect on GPH and added a couple of couple hundred RPM, a couple of knots, reduced fuel flow. Tabs has a negligible affect because no tab was required planing, and precious little for ride control. Had a friend with a 208/200 hp, and I'd call that motor performance minimally satisfactory, at best. Make sure motor height is optimal, as in the vent plate skimming the surface at cruise ...
Was that a 4 stroke 200? If so and it was not the newer 4 cly light weight, it will perform like the original 150 2 stroke and perhaps a bit slower to plane. I have a 208 with a 150 2 stroke and that motor is perfectly OK for one or two passengers. With three or four, there is a noticeable increase in time to plane. With a full tank and 3 adults, it has to work fairly hard.Curmudgeon said:
If I were to repower my 2001 208, I would choose the newer 200 4s and not any of the older 4s. My year does not have the added forward ballast to compensate for the extra weight of the older 4 strokes.
Of course, my Saltwater SX is still going strong and hopefully will continue to do so. ( Now, I've done it)
You may be experiencing prop slippage at the prop hub. If the hub is starting to go then this may be the answer to your speed loss. Remove the prop and have it checked if you have any questions. An aluminum prop is not too expensive to have repaired.
Was that a 4 stroke 200?
No, a Yamahaha 2-stroker. He subsequently re-powered with a 225 (still 2-stroke), and it was a world of difference ... :wink:
No, a Yamahaha 2-stroker. He subsequently re-powered with a 225 (still 2-stroke), and it was a world of difference ... :wink:
Thanks great info here! Ok so I took her out with a buddy today off San Diego coast. Winds were 20-30mph chop 2-4's. Cruise was actually a bit slower at about 17 knots in these conditions. I did mess around with the trim quite a bit trying to find that sweet spot. Since my results were similar once again, maybe my problem is the prop?
It is a Viper stainless steel 3 blade stamped as174889. Diameter 15", pitch 17". Do these specs seem right?
It is a Viper stainless steel 3 blade stamped as174889. Diameter 15", pitch 17". Do these specs seem right?
Cruise revs are right around 3800-4000. Gear ratio for a 1993 Johnson 200 from what I have researched is 1.86. I am going to test again next week with 1/2 tank fuel but it seems like I am off by 10mph at cruise with similarly configured 208's
Could the throttle linkage to the carbs be messed up.? I rebuilt all 6 carbs but didn't mess with any of the linkage. Motor runs strong, no obvious backfiring or hesitation.
Could the throttle linkage to the carbs be messed up.? I rebuilt all 6 carbs but didn't mess with any of the linkage. Motor runs strong, no obvious backfiring or hesitation.
Also regarding the weight issue, wow your not kidding. We went out with a full tank of gas and my bait tank only 1/2 full which is about 150lbs and is centered at the back of the cockpit. Me and my buddy were making bait and the macs that fell off the sabiki were swimming in the back of the cockpit! Scuppers were fully submerged. Going to have to move the bait tank forward for sure.
Tried to optimize the trim and According to the prop slip calculator, rough estimate shows 53% slippage. 17" prop, 3800 rpm, gear ratio 1.86, 18 mph on GPS. Will retest again as soon as I can get back on the water.
I had Viper props but changed to Rebels for better low-speed planing performance. I lost some top-send speed in the process. I plotted the slip for both props here. (The Vipers are the faster of the two props)
http://www.etecownersgroup.com/post/pro ... 1279034031
Could the boat be overweight for some other reason? Like waterlogged foam?
http://www.etecownersgroup.com/post/pro ... 1279034031
Could the boat be overweight for some other reason? Like waterlogged foam?