Got test two more props

[duknut51]

Went with the wife and tested a couple different props today on the Seaark.
1 solas rubex 4 blade
rpm mph
3000 19
4000 27
5000 34
5500 37 max rpm for my engine
6100 40 I know its over but had to see. Around 8% slip

2 powertech raf 13.25x17
3000 25
4000 33
5000 40
5100 41 max for this prop 2% slip

3 merc vengeance 13x18
3000 24
4000 33
5000 42
5400 44 max 4% slip

I know I have posted The Mercury prop before but not with fishing equipment and on a warmer day. I love the way the solas made the boat feel and how it preformed. It never porpoised and run like a champ. I know the rpms are high but I am going to use it for heavy loads, tubing and snagging where I would loose 600rpm on my old yamaha props. The powertech on the other hand porpoised a little and didnt get the rpm I had hoped for but thats what you get comparing to different prop manufactures. The vengeance did as it always does, a good job. I hope others can learn from my experiments and below is some of my other posts on the subject and posts of interests. thanks Kelly

http://forums.iboats.com/showthread.php?t=454532
http://forums.iboats.com/showthread.php?t=382110
http://forums.iboats.com/showthread.php?t=382020
http://www.bbcboards.net/zerothread?id=576525
http://www.walleyecentral.com/forums/showthread.php?t=175465&highlight=powertech

 

[mommicked]

Re: Got test two more props

What was the pitch of the Rubex?And whats your hp and boat model?If you dont mind my asking.

 

[duknut51]

Re: Got test two more props

Oh no problem. 13x15 my bad i forgot. 90hp yamaha 2 stroke xv180 sc. thanks kelly

 

[mommicked]

Re: Got test two more props

Thanks.I recently changed my yamaha alum. 17" 3 blade for an alum. Rubex 17" 4 blade.As you seemed to find my G3 1860 sc Jon performs much better w the 4 blade.I have a F90 and my steering is more responsive, my boat is much more stable in turns at speed,seems to run smoother,and throttle response up and down(panic stop!) is better.I can trim farther before porpoising starts.Its even better at putting the boat on the trailor in the wind.I havent got a tach. yet but will soon,I keep saying.Im guessing that my wot rpms will be within my recomended 5000/6000 by your data, though I believe your C ark is slightly heavyer than mine and I could be above 6Gs also.Ill find out soon.From about 5 mph my boat almost jumps on plane!It carves almost like a deep V.Im kicking myself for not getting a 4 blade sooner!

 

[duknut51]

Re: Got test two more props

I have a friend that I ordered a 19p solas off of Iboats for and I may try it some time just to see. I checked the weight difference in boats and your is about 50lbs lighter but your engine is 100lbs heavier by the websites. It just seems me that all the reading I have been doing that a four blade prop works great on these jon boats maybe not the express hyper-lift. I dont know its just fun to get out on the lake and do something after a long winter. Thanks Kelly

 

[mommicked]

Re: Got test two more props

Im definately stern heavy w the 4,Gas and batteries in the back too!They say 4 blades lift the stern and I believe it!How does your cavitation plate line up w the hull? mine is slightly below at hole # 2, but perf.is fine to me now w the 4 blade.My bud just got a 20' Rivercat all decked out w suzuki 115 4,Its beyond awesome and rides like a glass boat.He could have bought an offshore boat for what he's got in it!Sea Ark builds the strongest jonboats Ive seen around here.

 

[duknut51]

Re: Got test two more props

Hoe this helps. The bottom of the tape is where the keel hit the motor and the black line is where the bottom of the hull hits the lower unit. I think its 2-2.5 inches above bottom. thanks Kelly

 

[mommicked]

Re: Got test two more props

Your motor is definately higher,and it appears to be mounted all up,#4 hole.Im afraid to raise mine higher than hole #2 because the motor is so top heavy I think it might affect the stability and ruin my transome!!But I can feel it wanting to go faster just before it begins to porpoise.G3 would not give a straight answer when I asked if I could raise it higher safetly.But its plenty fast now anyway.My buds rivercat is camo everything from the suzuki to the trolling motor.40 gal livewell!?some kind of tough no slip lining all the topsides,two ridin seats about 30" wide each and very comfy and the ride is nowhere near my 1860 in terms of smooth.Ive got a 4x4 w broke shocks on washboard,his is like a new Caddy ridin on the beach!!Thanks for the info duknut I appreciate it alot.nice boat you got there also.

 

[duknut51]

Re: Got test two more props

Well thanks. Yes the engine is mounted in the 4th or the highest position and runs the best there. I have had it for a couple of years and really like it. It rides smooth with the 15 degree hull and handles very well. I had a lowe 1860 vds before this boat I had bought in 2004. It wasnt a bad boat it had an 8 degree hull very close to the g3s. Had it parked at my fathers house and a huge oak tree decided to fall on his building and car port that my and his boat was parked under well after the insurance payed me I was able to get this boat. Now the Lowe with this 90 mounted in the 2nd and a 13x19 yamaha aluminum prop that I sold would run around 40mph with 2 people. I never mounted the engine any higher and only really got interested in more speed until the place that I bought the seaark from said that it should run 45 plus mph. Now the seaark with the engine mounted in the 2nd hole and the same prop would run 40mph with 2 people as well. So today was able to go out and run the 12.5x19 solas 4 blade that my friend has and here are the numbers.
rpm speed
3000 23
4000 32
5000 40
5250 43 and It porpoised at full trim?
I used the 13x15 solas for snagging and it works excellent. Very smooth for idling and Had about another 400 lbs or gear and fish at the end of the day and run like a champ with little or no loss in performance. I am very impressed and love this forum have learned a lot here. Thanks Kelly

 

[mommicked]

Re: Got test two more props

Thanks for the feedback,Ive not found alot of perf. advice anywhere for jon boats.I guess they're not considered fast or powered for speed/perfomance alot.