prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

[Railrider1920]

Hi folks,
I am new to boating as well as the site. I had asked a few questions about fiberglassing a couple years ago, but that was about it.

I recently got a 1993 regal bow rider. Some, specs on it are:
model number 176 SE-SC IO.
It is 17' 3" long (on title)
3.0 L engine, not sure of the HP
Max RPM of 4800 (from previously owner, also the engine builder)
Mercruiser Alpha one out drive that has a 1.98 to 1 gear ratio.
left factory with standard 13.75" D x 19" pitch,probably a Michigan wheel.
Items in bold is info I got from a regal rep over the phone, who looked it up for me. He also said that with todays props I could probably go with a 14" D prop. 19" pitch for cruising around, down to a 17" pitch for tubing and such.

When I got it, it came with an aluminum prop that measured 13.25" D with a 17" pitch. This was measured on a computer by a prop shop in my area. The prop did not have any markings on it except for a "Y". I found out later that that prop came off of a Yamaha outboard. It will run fine, but it takes a while to come up on plane. once on plane, it will get up to about 28mph. This would be fine if I was just going to use it for running around or fishing, but we would really like to try some tubing and or skiing. The hole shot to do these just wont work, so I'd like to get a different prop.

The info below is RPM's and speed. Speed was measured with a handheld GPS, RPM's from gauge in dash. This is with two adults in the boat (450-500lbs) with maybe 10-15 gal of gas and a 20 lb cooler. Higher top end speed will be good, but mainly looking for better hole shot for tubing/skiing.
If you would like any additional info, I will try to provide it. If anyone has any suggestions on a prop to go with, I'm all ears.

Anyone in the Fort Walton Beach Fla area have a prop I might be able to borrow to try out?
Thanks for any suggestions
Rob

3400rpm 10mph-just starts to plane out. This was just taking it easy, slowly advancing the throttle.
400rpm 22.1-22.9mph
4400rpm 26.5 mph
4600rpm 28.2mph
4630rpm (the 30 was an estimate) 28.6 to 28.8
All of these were in the bay with a slight chop

Calmer water
4100rpm 23.7 mph
4400rpm 27.2 mph

 

[Fastatv]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

I have a similar size boat, a 17 foot Larson DC 170, with a 3.0 and SE106 outdrive, which I think is still a Mercruiser drive. I don't know the gear ratio of the drive. Anyway, I run a Mecruiser 14 X 19 stainless. The boat plains in five to eight seconds, with three adults on-board. At 3200, runs about 23, 24 mph, at 4800, runs about 39 mph. I would think that your boat would perform similar to mine.

 

[Railrider1920]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

Fastatv,
Thanks for the reply. I got ahold of a SS 14.25 x 19 from a friend. I'm going to give that one a try when I get it back from the prop shop. It was spun so I am having a new hub setup put in it. The shop is also going to measure it and tell me exactly what it is. Hopefully it will work a bit better than the 13.25 Al I have.

Went out and did some fishing yesterday. Got a 16" trout and a few black snapper or mangrove snapper. Not exactly sure which they are. I've had people tell me both names for the same fish. When I got home, the axel snapped while backing it into my yard. So now I'll have another project to finish before I can try out the prop.

Thanks again
Rob

 

[Fastatv]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

The axle is bad news, but at least it failed in your back yard...better than on the highway for sure. Yep, after you try the different prop, get on here and let us know how it works out. And if it isnt exactly what you need, you can always have it bent an inch of pitch in either direction. Rick

 

[steelespike]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

Assuming the tach is accurate at 4630 you have about 23% slip. 10 to 12 would be more normal.The Yamaha prop is at fault.
But the more troubling number is 4600 with a 17" pitch. on a 17 ft boat. It should be over revving.
While the 19" is the correct pitch it will very likely further reduce your rpm.
I think you have a motor issue. Hopefully just a tuneup or throttle adjustment.

 

[Railrider1920]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive New number

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive New number

Steelespike,
Sorry I didn't say it a month ago, but thanks for your input on my prop issues. The engine was rebuilt at the beginning of the summer.

I finally got an axel under the trailer and got it out today with the SS 14.29 x 19 on it. So I have some new and different numbers. But to get the prop on there, I had to take off the little verticle fin that was bolted onto the out drive, located under the horizontal bolt on whale tail. Hope that makes sense.

Edit: one 240 lb person and a little over half a tank of gas, guessing approx 10 gal.
RPM's.........Speed by handheld GPS
3200--------19.3 mph
3400--------22
3600--------24.8
3800--------26.6
4000--------28
4200----30.7 WOT

Getting on plane from a float with the throttle wide open. Done 3-5 times and came up with pretty much the same numbers each time.
3600----19 mph

Specs From original post
" 1993 regal bow rider. Some, specs on it are:
model number 176 SE-SC IO.
It is 17' 3" long (on title)
Max RPM of 4800 (from previously owner, also the engine builder)
3.0 L engine, not sure of the HP
Mercruiser Alpha one out drive that has a 1.98 to 1 gear ratio.
left factory with standard 13.75" D x 19" pitch,probably a Michigan wheel."

Getting up on plane is much better. If possible, I'd like to see it even better than this for tubing and sking. I'd also like to be able to get up to max RPM's of 4800. If I did, I'm guessing it would increase my speed as well.

Would anyone care to offer any suggestions on what size and pitch to go to after this?
Thanks
Rob

 

[steelespike]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

I think the 19" prop should be a darn close match It should make about 4800 rpm and a speed close to 40.
Hole shot is measured by time to get on plane.
The lack of power/speed/rpm points to the motor or the installation.
Its also possible a well setup 3.0 17 footer would run over 40 with a 21" prop.
Not great for water sports but good top speed and reasonable hole shot.
If it has a hydro foil on it it could be slowing things a little.You should try it without.
Don't assume that just because its a new setup that everything is right.
Be sure the timing is set right and advances as it should.Throttle open all the way.
Does it respond to up trim?

 

[Fastatv]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

I agree with steelesspike and another that posted here. I would have thought you would over-rev with the 17 pitch, and be about right with the 19. I can say this, with my 19 pitch, I could only get about 4200, light load, several inches of chop. I suspected a carb issue, and even though it was rebuilt one day before I purchased the boat...and by an alleged professional ( right ), I pulled the carb, gave it a good cleaning as the main jets had a green build up inside them, installed carb, took the boat out, it then turned 4850 with a light load, and cooler weather ( better air density = better performance ). As mentioned, have a look at initial timing and advance as well and verify throttle is opening to the WO position. Unless you have a way heavy 17 footer, I think you should pull more R's than what is indicated. Also, is the bottom of the boat slick? The vertical fin is your trim tab and is used to offset steering torque and, as a sacrificial anode. Rick

 

[Railrider1920]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

Thank you both very much for your input. I will look into the motor some more.
Timing
general tune up things (plugs, wires, distrib )
carb
Throttle
Anything else you'd suggest?

"Does it respond to up trim?" Yes it does, I think. When triming the outdrive up (to come out of the water) the bow raises. Is that what you meant Steelspike?

Went out yesterday and again today. We got enough mangrove snapper for to eat dinner tonight. Fun fighting fish.

The motor has sounded fine so far (to me anyway). Today it was windy and getting chilly. After being out on the water for a while, I went to advance the throttle (from an idle, in gear) and the motor hesitated and "coughed" Then was fine. Not sure what to call it. It wasn't a back fire with a slight bang, but more like a hiccup or cough. Sorry, I'm not very mechanically inclined when it comes to engines. Not sure what else to call it.

Trim tab, thanks Fastatv. Are there any diagrams or drawings around that have the parts of a boat labeled?

Thanks again
Rob

 

[Fastatv]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

Thank you both very much for your input. I will look into the motor some more.
Timing
general tune up things (plugs, wires, distrib )
carb
Throttle
Anything else you'd suggest?

"Does it respond to up trim?" Yes it does, I think. When triming the outdrive up (to come out of the water) the bow raises. Is that what you meant Steelspike?

Went out yesterday and again today. We got enough mangrove snapper for to eat dinner tonight. Fun fighting fish.

The motor has sounded fine so far (to me anyway). Today it was windy and getting chilly. After being out on the water for a while, I went to advance the throttle (from an idle, in gear) and the motor hesitated and "coughed" Then was fine. Not sure what to call it. It wasn't a back fire with a slight bang, but more like a hiccup or cough. Sorry, I'm not very mechanically inclined when it comes to engines. Not sure what else to call it.

Trim tab, thanks Fastatv. Are there any diagrams or drawings around that have the parts of a boat labeled?

Thanks again
Rob

Have a look here Rob. This link should answer some of your questions in regards to engine and outdrive but I don't think there is anything much on "boat terminologies. Rick
http://forums.iboats.com/non-repair-i-o-inboards/adults-only-no-exceptions-511070.html

 

[steelespike]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

Yes the bow should rise with up trim.
As long as you have the plugs out it won't hurt to do a compression check.
If the motor was completely apart if all else fails you might want to check valve timing.
We had a car the dealer missed the valve timing when doing a head gasket.
No problem till the first cold day it wouldn't start. They admitted their mistake and of course
fixed it no charge.
Valve timing is a real stretch but if all else fails wouldn't hurt to check.
I think we'll find something else before coming to that.
The hesitation/cough could be timing or a carb problem.

 

[Railrider1920]

Re: prop sugg. for' 93 17'Regal bow rider w/ mercruiser alpha one outdrive

Thanks Guys,
This will give me somewhere to start. Probably try doing some work on it in a week or two. Have to head out to work for a few days.
Thanks for the link. Took a quick look at it and it looks like it will have some great info there.
Rob