Volvo Penta 275 New Prop???

[jjohns2vt]

Hello - First post here..
I have a

1. 1987 Bayliner Capri 1950 Bowrider with original engine/sterndrive.
2. Its a standard 19 ft 6 inches.
2a.Its 120-130hp
3. Full with 30 gallons, and 2 children total of 90pounds, 2 adults total of 350 pounds
4. Use boat for skiing, fishing, cruising
5. Is it a Deep Vee, with unknown degrees to me of deadrise
6. 1987 volvo penta 275 engine, AQ131A
7. Gear ratio of motor -- Dunno...

I have a beat up, hammered back into reasonable shape michigan 14 X17 pitch prop.. This prop at WOT goes 33-34 mph planes at 20-25 mph at 5400 RPM... I used a 14 X19 pitch Volvo Penta prop which at WOT goes 34-35 mph, planes at 20-25 mph at 4500RPM...
I am wondering what my best prop would be for this boat..Wanna ski and cruise. I am curious about a 19 pitch 4 blade prop???Any ideas welcome..

Just got boat, engine compression is good around 170psi. I am restoring/repairing boat..Thanks Again!!

 

[robjen1019]

Re: Volvo Penta 275 New Prop???

I had a simmilar boat last year and I settled with a 4 blade aluminum 17 pitch prop. had really good hole shot and at wot 5400 it was at 34mph. It really pulled the tubes nice, and planed at 15 to 17 mph loaded with family of 5 on 19ft boat.

I went with a solas 4 blade al. They are only 120 compared to the volvos which are much more money. Iboats might still have them on sale.

 

[robjen1019]

Re: Volvo Penta 275 New Prop???

another thought, you might try venting the prop with a drill. supposed to help with larger motor.
I cant remember how to do it, but there are instructions how to do it to it to mercruiser props

 

[jjohns2vt]

Re: Volvo Penta 275 New Prop???

So I understand that the 4 blade prop gives a better hole shot, but would I go with the same pitch that I have now, or to a 19 pitch if its a 4 blade.. Is 34 mph about the top for this boat?

Also... I noted with the 19 pitch prop that the boat was harder to steer. The 17 pitch took almost no pressure on steering wheel to control, but the 19 pitch takes a lot more pressure/strength to turn and then it eventually seems to give and steer more easily (??maybe easier on plane) Thanks

 

[hwsiii]

Re: Volvo Penta 275 New Prop???

J, sorry it took a while, I forgot. If you will fill this out I will help you every way I can.

Iboats Boat and Motor Info

1. Year, make and model of boat
2. Length, width and base weight of boat, look for boat decal on back of boat
2a.What is the maximum recommended HP for your boat
3. Number of people and gallons of gas normally on boat
4. What do you use the boat for
5. Is it a Deep Vee and if so how many degrees of deadrise
6. Year, make. manufacturer and model of motor
7. HP and gear ratio of motor IMPORTANT
If you don?t know the ratio, you need to pull the plugs out and put a piece of tape across the prop and the lower unit and then cut it between the prop and the housing then do the same thing on the flywheel and turn the motor until the tape lines up with each other on the prop, it is easier if two people do this, so one can watch the prop while the other counts the revolutions of the motor
8. Manufacturer?s recommended Wide Open Throttle (WOT) range
9. Anti-ventilation Plate height above keel of boat if it is an outboard in inches, use a board under the keel and stiking out to the anti ventilation plate for a referene
10. Is it a bass boat or does it have a pad bottom
11. Does it have a hydrafoil, dolefin or trim tabs
12. Make, model, diameter, pitch, number of blades and whether SS or aluminum prop
13. WOT RPM and speed from your current prop and how much gas and how many people were in the boat for the test data and is the speed by GPS. Make sure you trim the prop up until it starts ventilating and then just trim in until it quits ventilating. If you do not have a tach you can buy a digital tachometer and hour meter here: http://cgi.ebay.com/ebaymotors/Tacho...Q5fAccessories
RPM ___________ Speed ___________ No. of people ____________ Gal. Gas ________
14. Are you at sea level or a higher elevation, give us the elevation in feet
15. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way, checked compression, and looked at the plugs and checked spark, all of the foregoing could be the reason your prop is not attaining full RPM
16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop
17. Does the prop show any damage that you can see
18. What problems are you trying to cure or what are you looking for the boat to do that it is not doing the way you think it should or to your expectations
19. If you are trying to attain a better cruising speed and fuel savings or trying to attain a faster speed I will want you to take your boat and run it with 1 or 2 people and give me the RPM and speed readings starting at 3,000 RPM in 500 RPM increments all the way to WOT.

REMEMBER, The numbers I give you will be NO better than the information you give me

The only thing I ask of you is to come back and give me a report of WOT RPM and speed for my database.



H