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#1
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I'm looking for help in selecting a new prop. I'm currently running a 14
1/4x 23p 3 blade that came on the boat from the factory. The boat is a 2003 Larson SEI 190 (open bow runabout) with a 4.3 volvo sx sterndrive. It will turn this prop 4600 rpms (4200-4600 reccomended by volvo at WOT) and 49 mph according to speedometer at WOT. This summer we have started doing alot of slalom skiing. Needless to say it is a bit lacking on power to pull up a 200# plus skier . I have been looking at 4 and 5 blade props but am at a loss as to what size should work best for me. Also is there a big trade off for power to loss of top end? I need something that will be a good all around prop as we do alot of tubing and wakeboarding as well as just cruising around the lake. I do not have a local dealer that will let me try out different sizes. I'm not afraid to spend some $ on a good prop, but dont want to experiment with sizes at the prices of these props. Thanks for any help Steve |
#2
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You can't have your cake and eat it too! That said since you need the low
end pull for all the fun then drop pitch to 21 but keep an eye on your RPM for them speed runs. You should have no worries running that 4.3 to 4800. I had a 5.7 which was in the same 4200-4600 but propped for 4900rpm, 10 years later and still no engine problems. "Steve" wrote in message ... I'm looking for help in selecting a new prop. I'm currently running a 14 1/4x 23p 3 blade that came on the boat from the factory. The boat is a 2003 Larson SEI 190 (open bow runabout) with a 4.3 volvo sx sterndrive. It will turn this prop 4600 rpms (4200-4600 reccomended by volvo at WOT) and 49 mph according to speedometer at WOT. This summer we have started doing alot of slalom skiing. Needless to say it is a bit lacking on power to pull up a 200# plus skier . I have been looking at 4 and 5 blade props but am at a loss as to what size should work best for me. Also is there a big trade off for power to loss of top end? I need something that will be a good all around prop as we do alot of tubing and wakeboarding as well as just cruising around the lake. I do not have a local dealer that will let me try out different sizes. I'm not afraid to spend some $ on a good prop, but dont want to experiment with sizes at the prices of these props. Thanks for any help Steve |
#3
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Go w/ the 4 blade SS performance prop in a 22 or 23 pitch. Diameter will be
a little less which will make up for the extra blade surface. Expect to loose about 3 mph on top end. Reason I say 22 or 23 is the 23 will be the right prop but some manufacturers make 22, 24 and some make 21, 23. The 22 will loose about 5 mph on top end over your current configuration. You might also install a whale tail. They do help for skiing purposes. -- Tony my boats at http://t.thomas.home.mchsi.com "Steve" wrote in message ... I'm looking for help in selecting a new prop. I'm currently running a 14 1/4x 23p 3 blade that came on the boat from the factory. The boat is a 2003 Larson SEI 190 (open bow runabout) with a 4.3 volvo sx sterndrive. It will turn this prop 4600 rpms (4200-4600 reccomended by volvo at WOT) and 49 mph according to speedometer at WOT. This summer we have started doing alot of slalom skiing. Needless to say it is a bit lacking on power to pull up a 200# plus skier . I have been looking at 4 and 5 blade props but am at a loss as to what size should work best for me. Also is there a big trade off for power to loss of top end? I need something that will be a good all around prop as we do alot of tubing and wakeboarding as well as just cruising around the lake. I do not have a local dealer that will let me try out different sizes. I'm not afraid to spend some $ on a good prop, but dont want to experiment with sizes at the prices of these props. Thanks for any help Steve |
#4
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Steve wrote:
I'm looking for help in selecting a new prop. I'm currently running a 14 1/4x 23p 3 blade that came on the boat from the factory. The boat is a 2003 Larson SEI 190 (open bow runabout) with a 4.3 volvo sx sterndrive. It will turn this prop 4600 rpms (4200-4600 reccomended by volvo at WOT) and 49 mph according to speedometer at WOT. This summer we have started doing alot of slalom skiing. Needless to say it is a bit lacking on power to pull up a 200# plus skier . I have been looking at 4 and 5 blade props but am at a loss as to what size should work best for me. Also is there a big trade off for power to loss of top end? I need something that will be a good all around prop as we do alot of tubing and wakeboarding as well as just cruising around the lake. I do not have a local dealer that will let me try out different sizes. I'm not afraid to spend some $ on a good prop, but dont want to experiment with sizes at the prices of these props. Thanks for any help Steve I would go for a 3 blade stainless 21" double cupped. It should give you improved holeshot with superior water-holding & comparable top end speed & rpm's... maybe just a little higher rpm's. For a wild set-up, go for the Land & Sea Torque-Shift variable pitch prop... holeshot out at 13"-14" and top end speed at 23"-24". Your boat will "jump" out of the water! Rob |
#5
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Not sure why you say this Rob. A 21 double cupped will definetly help on
the hole shot but will overrev by about 250 rpms. The double cupping adds bite and creates extra drag which reduces the rpms without adding pitch. It will also slow the boat down considerable due to the fact that your now turning a 21 instead of a 23. Expect about 5 mph drop in top end if you keep the rpms at 4600 (don't overrev). As for the Torque Shift prop - I don't care for the maintenance of the prop springs and the cracked hubs and the stress on the lower unit. They do work but are not worth the money and maintenance costs. -- Tony my boats at http://t.thomas.home.mchsi.com "trainfan1" wrote in message ... Steve wrote: I'm looking for help in selecting a new prop. I'm currently running a 14 1/4x 23p 3 blade that came on the boat from the factory. The boat is a 2003 Larson SEI 190 (open bow runabout) with a 4.3 volvo sx sterndrive. It will turn this prop 4600 rpms (4200-4600 reccomended by volvo at WOT) and 49 mph according to speedometer at WOT. This summer we have started doing alot of slalom skiing. Needless to say it is a bit lacking on power to pull up a 200# plus skier . I have been looking at 4 and 5 blade props but am at a loss as to what size should work best for me. Also is there a big trade off for power to loss of top end? I need something that will be a good all around prop as we do alot of tubing and wakeboarding as well as just cruising around the lake. I do not have a local dealer that will let me try out different sizes. I'm not afraid to spend some $ on a good prop, but dont want to experiment with sizes at the prices of these props. Thanks for any help Steve I would go for a 3 blade stainless 21" double cupped. It should give you improved holeshot with superior water-holding & comparable top end speed & rpm's... maybe just a little higher rpm's. For a wild set-up, go for the Land & Sea Torque-Shift variable pitch prop... holeshot out at 13"-14" and top end speed at 23"-24". Your boat will "jump" out of the water! Rob |
#6
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Do any of you have any experience with the Mercury High Five props?
Steve wrote in message ... I'm looking for help in selecting a new prop. I'm currently running a 14 1/4x 23p 3 blade that came on the boat from the factory. The boat is a 2003 Larson SEI 190 (open bow runabout) with a 4.3 volvo sx sterndrive. It will turn this prop 4600 rpms (4200-4600 reccomended by volvo at WOT) and 49 mph according to speedometer at WOT. This summer we have started doing alot of slalom skiing. Needless to say it is a bit lacking on power to pull up a 200# plus skier . I have been looking at 4 and 5 blade props but am at a loss as to what size should work best for me. Also is there a big trade off for power to loss of top end? I need something that will be a good all around prop as we do alot of tubing and wakeboarding as well as just cruising around the lake. I do not have a local dealer that will let me try out different sizes. I'm not afraid to spend some $ on a good prop, but dont want to experiment with sizes at the prices of these props. Thanks for any help Steve |
#7
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On Thu, 09 Sep 2004 01:00:54 GMT, "Tony Thomas"
wrote: Not sure why you say this Rob. A 21 double cupped will definetly help on the hole shot but will overrev by about 250 rpms. The double cupping adds bite and creates extra drag which reduces the rpms without adding pitch. It will also slow the boat down considerable due to the fact that your now turning a 21 instead of a 23. Expect about 5 mph drop in top end if you keep the rpms at 4600 (don't overrev). As for the Torque Shift prop - I don't care for the maintenance of the prop springs and the cracked hubs and the stress on the lower unit. They do work but are not worth the money and maintenance costs. I have a question for you. My friend who has the engine problems also has a prop problem. He is currently swinging a 14 1/2 x 23 on an Evinrude 200 FICHTand gets about 38 mph at 5400 rpm WOT fully trimmed out. He can change pitch which changes RPM but no relative increase in speed - in fact with a 21, he got 5700 RPM and lost four mph. The engine is properly installed, etc. Any idea why? Later, Tom |
#8
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Tony Thomas wrote:
Not sure why you say this Rob. A 21 double cupped will definetly help on the hole shot but will overrev by about 250 rpms. The double cupping adds bite and creates extra drag which reduces the rpms without adding pitch. You almost answer your own question here... It will also slow the boat down considerable due to the fact that your now turning a 21 instead of a 23. Expect about 5 mph drop in top end if you keep the rpms at 4600 (don't overrev). This should be somewhat offset by the switch to a precision SS prop from a cast aluminum wheel - typically minimal loss of top end... As for the Torque Shift prop - I don't care for the maintenance of the prop springs and the cracked hubs and the stress on the lower unit. They do work but are not worth the money and maintenance costs. For a Mercruiser Alpha, you are correct, but a Volvo SX should be able to handle it... esp. with the V-6. Rob |
#9
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The high five is a very good prop but most people don't want to spend the
money for one. Should work great. -- Tony my boats at http://t.thomas.home.mchsi.com "Steve" wrote in message ... Do any of you have any experience with the Mercury High Five props? Steve wrote in message ... I'm looking for help in selecting a new prop. I'm currently running a 14 1/4x 23p 3 blade that came on the boat from the factory. The boat is a 2003 Larson SEI 190 (open bow runabout) with a 4.3 volvo sx sterndrive. It will turn this prop 4600 rpms (4200-4600 reccomended by volvo at WOT) and 49 mph according to speedometer at WOT. This summer we have started doing alot of slalom skiing. Needless to say it is a bit lacking on power to pull up a 200# plus skier . I have been looking at 4 and 5 blade props but am at a loss as to what size should work best for me. Also is there a big trade off for power to loss of top end? I need something that will be a good all around prop as we do alot of tubing and wakeboarding as well as just cruising around the lake. I do not have a local dealer that will let me try out different sizes. I'm not afraid to spend some $ on a good prop, but dont want to experiment with sizes at the prices of these props. Thanks for any help Steve |
#10
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You are exactly right. Dropping to a 21 will increase rpms by about 300 and
drop your speed. You would have to increase rpms by 500 to maintain the same speed w/ a 2" drop in pitch. However, something does not add up based on the numbers. 23 x 5400 / 1056 / 1.86 = 63 mph. That means you have a 60% efficiency. Even if you had a 2:1 gearcase you still have a theoritical speed of 58 mph which gives a 65% efficiency. -- Tony my boats at http://t.thomas.home.mchsi.com "Short Wave Sportfishing" wrote in message ... On Thu, 09 Sep 2004 01:00:54 GMT, "Tony Thomas" wrote: Not sure why you say this Rob. A 21 double cupped will definetly help on the hole shot but will overrev by about 250 rpms. The double cupping adds bite and creates extra drag which reduces the rpms without adding pitch. It will also slow the boat down considerable due to the fact that your now turning a 21 instead of a 23. Expect about 5 mph drop in top end if you keep the rpms at 4600 (don't overrev). As for the Torque Shift prop - I don't care for the maintenance of the prop springs and the cracked hubs and the stress on the lower unit. They do work but are not worth the money and maintenance costs. I have a question for you. My friend who has the engine problems also has a prop problem. He is currently swinging a 14 1/2 x 23 on an Evinrude 200 FICHTand gets about 38 mph at 5400 rpm WOT fully trimmed out. He can change pitch which changes RPM but no relative increase in speed - in fact with a 21, he got 5700 RPM and lost four mph. The engine is properly installed, etc. Any idea why? Later, Tom |
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