1988 OUTRAGE 18, Yamaha F115B

[FISHNFF]

I got back my 1988 Boston Whaler OUTRAGE 18 boat from the shop. If you remember [the boat had] a crack in the keel; it was fixed. The hull bottom was cleaned. The new Yamaha F115B now has 48 hours, and its crankcase lubrication oil and gear case lubricants were changed. The fuel filter was also changed.

The engine mounting height was raised one hole. [In a prior report the engine was described as being mounted one-hole-up, so it is now mounted two-holes up.]


Acceleration was strong, with no cavitation or ventilation, and the 17-pitch, black, SS, Yamaha K propeller held bite in turns. [The boat speed was] 35 knots [that is, nautical miles per hour, which would be 40.3-MPH] either direction turning [an engine speed of] 6,100-RPM.

Likes:
--acceleration quicker than original 2000 Yamaha F115
--oil drain plug and spout easier to drain.
--looks better

Dislikes:
--hard to find neutral, and pulling back throttle often goes past neutral into reverse.
--higher cruising engine speed

Undecided:
--sound level seems about the same.
--vibration seems the same.
--mileage looks about the same.


More to come--FISHNFF

[Peter]

Thanks for the report. I wouldn't expect significant differences given that there are not significant differences between the old and new motors.

[JRP]

Thanks for the report. Just to confirm, your top speed of 35 was reported in nautical miles per hour, not statute miles per hour?

[jimh]

There is a previous report on the performance of the Yamaha F115B on this1988 Boston Whaler OUTRAGE 18 in a thread from the old forum.

In that previous report the boat speed was reported to be (32.5-nautical miles per hour or) 37.4-MPH. It appears that by raising the engine mounting height one hole to two-holes-up position the boat speed has now increased by 2.9-MPH to reach 40.3-MPH.

[Jefecinco]

Perhaps an adjustment to the shift linkage andcable or the binnacle by the installer could make the neutral detent more positive.

I encountered a similar situation with a 1999 Evinrude 115 HP when it was newly installed. Several attempts by the selling dealer made only a slight improvement. When I replaced the boat, a Dauntless 16, with a 190 Montauk and a 135 HP Verado I found that although electronic shift and throttle controls are expensive they certainly perform much better than did the cable shift and throttle controls on the Dauntless.

Butch

[FISHNFF]

[Confirms that when he mentions a speed of] 35.1 knots [he means nautical miles per hour, or] 40-MPH [ or actually 40.4-MPH in statute miles per hour].

I'm sure having the bottom polished helped a bit, too. Raising the motor an additional [hole] seems [to have been] fine. The same water is spraying up from the lower unit. I thought raising the motor would fix that. The new 115 is:
--lighter
--larger displacement
--new intake
--has a 130hp version on same block

Compared to a 13-year-old engine with over 800 hours on it, I would think the new would be faster. The new is quicker.

About the shifter: I had dealer do adjustments, tighten the shifter. I can't do anything to increase the neutral detent. I just gotta be careful.

[jimh]

A nautical mile is generally considered to be one minute of latitude, or a distance of 6076-feet. A statute mile (in the USA) is 5,280 feet. The conversion factor for changing knots or nautical miles per hour into miles per hour is thus 6076/5280 or 1.151.

If a boat speed is said to be 35.1-knots, the conversion into MPH yields 40.4-MPH.

If a typical GNSS receiver is used as a speed measuring device, one should be aware that a typical GNSS receiver cannot measure speed. It computes a speed based on the time and distance between two position fixes. Given the error in the position fix that is inherent in a GNSS receiver position, the speed measured is unlikely to be accurate to more than about 0.5-MPH. So when one says there was a boat speed and gives the speed with a resolution of 0.1-knots or 0.1-MPH, the actual speed could be anywhere from 0.25 higher or lower. It is common to see a lot of flutter in the speed data from a GNSS receiver, and it is also common for boaters to filter out the many readings and land on the highest one, or at least to take an average that is weighted toward the higher readings. I think that is human nature.

[flymo]

Fish, glad to hear the performance has improved so much with the fixes recommended on the old forum.

Are you running a Yamaha shifter, and if so, which one?

As I recall, the Yamaha shifters I have used have a hard detent lock at neutral, that is, when you go to neutral it locks there until you explicitly squeeze the safety latch on the grip. Yamaha's website indicates they updated their shifter models, and I am hoping they did not take that feature away, You can actually hydrolock and total a four-cycle engine if you inadvertently drop into reverse while traveling forward.

F

[Hoosier]

GPS speed measurements increase in accuracy as speed increases because there is more distance covered between fixes and the jitter in the calculated position is less apparent. Also 0.5-MPH error is less, percentage wise, at 30-MPH than it is at 4-MPH trolling speed.

[FISHNFF]

In the estuary [the time of the speed test] was around slack tide. [The maximum boat speed obtained at full throttle in nautical miles per hour was] 35.0 one way and 35.2 the other way.

The remote throttle is a Yamaha 704 top mount. There is no squeeze to take out of neutral. My side mount Yamaha has to be squeezed, as does my Mercury Quicksilver. The controls are much safer with this neutral safety lock.--FISHNFF

[Phil T]

Fish--the 704 is fussy with just a clicking sound to indicate neutral. It takes time to get used to the feel. I would hate a control the locked into neutral.

[FISHNFF]

I've been using a 704 on this 18 Whaler with the older F115. I have new Yamaha cables with this new motor. Seems still coming out of gear. No usual bends in cables.

I've used the 704 shifter on our '92 226 Grady/Yamaha and our '87 204C Grady/Yamaha. I just need to be more careful. I think it's the angle and height (for me).

[Tiz7070]

Perhaps you should have gone with [a Yamaha V MAX SHO® 115] which is called the F130B in Australia. I just purchased it last year and placed it on my 160 Dauntless. I have no performance numbers yet as it was just mounted and everything is still frozen up my way. I plan on running a 18-pitch four-bladed propeller by Yamaha, and I have [the Yamaha V MAX SHO® 115] mounted [two-holes up from the lowest position]. Supposedly this motor puts out 127-HP. In my opinion--I'm sure most would argue--hang the maximum [rated] horsepower on any boat, especially a Boston Whaler boat. I will share some performance data as soon as [the V MAX SHO® 115] is broken in correctly.

[jimh]

When in the future you have some performance information, please start a new thread here in PERFORMANCE to post the information about your results with a different boat and a different engine than the Boston Whaler OUTRAGE 18 and Yamaha F115B that are being discussed in this thread. I am sure your performance data with the different boat and different engine will be of interest to many.