Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: 19 Guardian 28kts @ 4000rpm tops?

Posted by rockfish777 on 09/27/12 - 7:44 AM
#1

Well I've never been a big Whaler fan, because of growing up around the 17 Montauk. Rough ride, and wooden console that was always loose. I had a 17 McKee craft for 10 years and was a great boat, but still rough riding. I've been looking for a shallow water boat with a good ride for the Chesapeake Bay, and OC MD. I found a 1991 Guardian 19' with 1998 150 Evinrude Ocean Pro. It's a retired DNR/ Sheriff dept boat. Very solid with some deadrise for a good ride. I seafoamed the engine, and checked compreshion. Mid 90's one side, and 105-108 other? Took it out for the first time yesterday and only runs 28kts by GPS, and 4000rpms, but if you trim it out some 4400rps max. The trim setting is in the second hole, and the prop is a Viper 14 3/4X21. The hour meter says 1700, but the guy in the Sheriff dept said that they didn't replace the hour meter when they changed engines? He said about half that. They had the boat 5 yrs and put on 300hrs. It also has a green, and red temp guage, and it was at the red, even on the hose in the yard, but I can still put my hand on the heads, and not burn them? Bad gauge. Great boat, very happy with the ride, but I don't want to ruin the motor. Also use 89 ethanol free fuel.
Thanks

Posted by Tom W Clark on 09/27/12 - 8:00 AM
#2

Wrong prop. The 21" Viper is too much pitch. That motor works well with 19" pitch Viper.

I do not understand what you mean by "The trim setting is in the second hole..." The motor has power trim and tilt, no?

If the motor is running hot, find the problem and fix it...now. Have you serviced the water pump? Replaced the thermostat? Inspected the internal cooling passages?

Montauks have fiberglass consoles, not wooden consoles. You probably grew up with an old Nauset or Currituck.

Posted by rockfish777 on 09/27/12 - 8:52 AM
#3

The old 17' Whalers I grew up with were 40 years ago with mahogany consoles. I just got the boat so haven't checked much out, it was on ebay, but a local boat. It was serviced by the sheriff dept less than 20 hours ago. I have a infrared thermometer that I'm going to try on the heads today on a hose. Would a 17 pitch be better? She idles and up to 1500rpms a little rough, but 3000-4000 is fine.

Posted by Tom W Clark on 09/27/12 - 9:04 AM
#4

Nope. The 19" SST/SSP/Viper is the one most commonly used on that boat/motor combination.

A 17" Stiletto Advantage or Turbo 1 would also yield about the same RPM. You want to end up between 5000 and 5500 RPM at WOT, trimmed out.

Posted by rockfish777 on 09/27/12 - 5:09 PM
#5

Went to the prop shop today, and could only find a raptor 14 1/2X18, took the boat out, and got 32kts @ 4700rpms. I got 3700rpms @ 23kts. The bottom is painted, and rough. The idle, and low speed is rough also. I'm going to try to get the carbs rebuilt to see if that helps. I ran it on the hose and the temp gauge was right at the red and green line, but I used an infrared temp gun and it said 147-152 on all parts of the head. I think the gauge is bad. I'll try to get a new gauge, and sensor.

Posted by Tom W Clark on 09/27/12 - 6:01 PM
#6

The bottom is painted, and rough.


That is going to have a HUGE effect on the speed of the boat. You need to get that straightened out before doing anything else

I presume you mean you tried a 14-1/2" x 18" Michigan RAPTURE, a decent model of propeller. Your boat should be good for 42-44 MPH (36-38 knots) at 5500 RPM with that motor.

Posted by Joe Kriz on 09/27/12 - 6:10 PM
#7

rockfish777 wrote:
took the boat out, and got 32kts @ 4700rpms. I got 3700rpms @ 23kts. The bottom is painted, and rough.

I need a little more clarification here.
To test a prop, you need to be at Wide Open Throttle (WOT) to check your WOT RPM's.

Are any of the speeds you show above taken at WOT?

Please let us know what your WOT RPM's are when testing a prop.

See this article on proper setup and testing of props/motors
http://www.veradoclub.com/smf/index.p...opic=137.0
It applies to all motor/boat combinations.

Edited by Joe Kriz on 09/27/12 - 6:31 PM

Posted by rockfish777 on 09/28/12 - 5:30 AM
#8

Yes, this is my WOT RPMS, and speed. I'm going to get an appointment for a carb rebuild to make sure the engine is ok, and have them check the tach.
Great info on engine height. I tried to see what hole the top bolts are in, but they have black covers, and ares ealed with caulk. I broke off a ss bolt trying to get one off. You have to excuse me on outboards, it's been a while since I had one. I have had inboards for the last 20+ years, but can't afford them anymore, and they aren't that good for shallow bay areas.
Thanks

Posted by rockfish777 on 10/04/12 - 5:42 PM
#9

I got my boat back from Bob's marine today. Carbs were fine, adjusted synk and lynk, and did compression test. Port side was low, and pulled head. He said slight scuff from carbon on rings, but very little carbon present now. Polished bores lightly with emory paper, and ran some ring free through her. This brought up compression 10#, but still about 15# less than star side. Raised engine to three holes or all the way up, and water tested her. Ran 4700rpms with a 14 1/2X18 raker prop @ 35 kts. I couldn't read it very well that why I thought it was a raptor, it's been reconditioned. He also tried a 17 prop, and got 150 more rpms. He said he likes to see 5500rpms with that engine. He also said the guardian is heavier, and that most 20 year old + whalers that have been kept in the water most of their life have gotten some water in them. He said the mounting holes should have been drilled 3/4" higher, and that's where he would like to see it, but didn't want to drill new holes that close together. The center of the top bolts are 2 1/4" from the top of the transome. I found a viper 19" like was recomended on craigs list. What do you think?

Posted by Tom W Clark on 10/05/12 - 7:34 AM
#10

Bob sounds like a very knowledgeable and experienced marine mechanic.

The top bolt holes should have been drilled between 1-3/4" and 2" (o.c.) from the top of the transom which is 1/4" to 1/2" higher than where they are now. They should not have been drilled 3/4" higher, though it would not be the end of the world if they had been. At any rate, you have the motor moved up as high as it can go now and that is a good start.

Yes, the Guardian is heavier than the Outrage. The weight difference is between 200 and 500 pounds, depending on whose specifications you believe. If your boat is 200 pounds heavier than a recreational Outrage then the speed is expected to be 2 MPH slower. If the boat is 500 pounds heavier, the speed is expected to be 4.5 MPH slower. If the former, you would still use a 19" SST/Viper. If the latter you might drop to a 17" pitch version.

However, if there is water in the hull then that means added weight and reduced speed. Likewise, if the bottom is rough, that is going to take a toll on boat speed and you need to get the bottom fair before finding the perfect prop.

If the motor is a little tired, then it's not as powerful as it once was and not going to generate as much speed.

Any of the things mentioned above could have a small impact on speed. Together, they can have a huge cumulative effect on speed, which is what I suspect is going on here.

I would not buy any propeller that has been "reconditioned" unless I knew what it looked like before it went to the prop shop and I took it to the prop shop I normally work with and explained what I expected them to do to it. "Reconditioned" can mean anything and you never really know what you are getting if you buy someone else's.

Posted by rockfish777 on 10/07/12 - 3:37 AM
#11

Has anybody tried a 15,16,or 17" prop on a 150hp. If so how did it perform, handle, and rpms.

Posted by rockfish777 on 11/14/12 - 5:44 PM
#12

I found a 17" Viper prop, and tried it today. Worked great 36.7 kts @ 5300rpms in a 10-15 kt wind. Boat is heavy, still has forward locker in front of console with anchor, and a lot of extra hardware and flood lights etc. Run almost level with a great ride in a chop. When trimmed out bow rises some, but still a very good ride for her size. I scraped the hull to get it as smooth as possible, with just me, and a 1/2 tank gas. Cruises at 28 kts @ 4200rpms. I think this will be as good as it gets for her. Thanks for all the help.