Prop advise
Moderators: Redneck_Randy, badmoonrising, lakerunner
Prop advise
Anyone out there a prop expert?
I took my toon out a while ago and at full throttle, I was barely getting up to 3k rpm... My boat has an aftermarket ss prop (14 pitch) and under one of the seats is what I believe to be the original aluminum prop which is a 13 pitch... Do you guys think that change would allow my motor to get up to full rpm? Is there any reason that someone would use a prop that would limit full rpm? I am stumped...
Also, the original prop has some nicks and gouges (minor) on the edges, should I take it in and have it fixed up or not worry about it?
I took my toon out a while ago and at full throttle, I was barely getting up to 3k rpm... My boat has an aftermarket ss prop (14 pitch) and under one of the seats is what I believe to be the original aluminum prop which is a 13 pitch... Do you guys think that change would allow my motor to get up to full rpm? Is there any reason that someone would use a prop that would limit full rpm? I am stumped...
Also, the original prop has some nicks and gouges (minor) on the edges, should I take it in and have it fixed up or not worry about it?
1999 Voyager 21' Express Fish triple toon 115hp Mercury (SOLD)
2004 Ford F150 SuperCrew
Boise Idaho
2004 Ford F150 SuperCrew
Boise Idaho
- HandymanHerb
- Site Admin
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Two words prop guard, but I don't think they work on anything bigger than 90 horse the last time I checked.
Our rocks float, there call gators and their head is hard and will take out a prop, I hit a 10 footer that was slow at getting out of the way , I hit with the keel of the toon and then he hit the prop-guard, that saved him and my prop.
I got a cut on the inside of the guard, but I didn't lose my SS prop
Our rocks float, there call gators and their head is hard and will take out a prop, I hit a 10 footer that was slow at getting out of the way , I hit with the keel of the toon and then he hit the prop-guard, that saved him and my prop.
I got a cut on the inside of the guard, but I didn't lose my SS prop
In Memory of John 6x6 Larsen
Mike, I don’t mean to sound discouraging, but it sounds like you may have other problems. Even if the props you have are not "dialed in" you should be getting more than 3000 rpm. I'm not sure of the exact specs on your Merc, but WOT should be around 5500 to 6000 rpm, and 13 or 14 pitch prop should have you a lot closer that that. I would have it checked out before you do much experimenting. You don’t want to risk expensive damages.
22' Landau Conquest/ 90HP Suzuki
1994 Chevy 3/4 ton 350
Wichita, Kansas
1994 Chevy 3/4 ton 350
Wichita, Kansas
I agree with Backlash
There's something not right if you can only get 3000 rpm's. You did unload it off the trailer first, LOL. Just a joke. No way the props you mentioned would limit your rpm's to that degree. Get your motor checked out before you play with props.
2005 Tuscany TS2286FC by Sweetwater
22 ft, 90 hp 4s Yamaha
Lorance 332c GPS/Fishfinder
Minnkota copilot Trolling motor
3 battery's, tandem axle trailer pulled by 05 Dodge Quad Cab Hemi 2x2.
22 ft, 90 hp 4s Yamaha
Lorance 332c GPS/Fishfinder
Minnkota copilot Trolling motor
3 battery's, tandem axle trailer pulled by 05 Dodge Quad Cab Hemi 2x2.
Mike also make sure your tach is set up properly and you are getting an accurate reading. BTW I have a 90hp Yamaha with a 13 5/8" X 13 pitch prop and it turns 5,400 rpm at WOT. What is your top end speed now?
2014 Tracker Targa V-18 Combo/ Mercury 150hp 4 stroke
'06 Dodge 1500 QC 4x4 Big Horn Hemi
Sheridan, Indiana
'06 Dodge 1500 QC 4x4 Big Horn Hemi
Sheridan, Indiana
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Mike a prop change is not going to get you 2000 more rpm's. You didn’t go into detail on how it ran at other RPM’s. I would start checking the Motor. Go in this order, if the first thing checks out move to the next.
1)Do a compression check. They should be within 10% of each other. Most motors new run 140-150 PSI. You will still run OK down to about 110 but motor will not perform as well.
2)Do a spark test to make sure you have spark at all cylinders. And check spark plug condition.
3)Check your fuel system. Filter, Pump, Carbs
It could be something simple like not getting enough fuel or major: bad cylinder or blown head gasket.
Good luck.
Here is a good site for DYI information
http://www.themarinedoctor.com
1)Do a compression check. They should be within 10% of each other. Most motors new run 140-150 PSI. You will still run OK down to about 110 but motor will not perform as well.
2)Do a spark test to make sure you have spark at all cylinders. And check spark plug condition.
3)Check your fuel system. Filter, Pump, Carbs
It could be something simple like not getting enough fuel or major: bad cylinder or blown head gasket.
Good luck.
Here is a good site for DYI information
http://www.themarinedoctor.com
I'd rather go "Getto" than not go at all
96 Manatou Limited
02 GMC Sierra
98 Camplite
96 Manatou Limited
02 GMC Sierra
98 Camplite
Very good advise... I just spent about two hours over at the other forum, man that guy is good with outboards!
Judging from the way the motor ran, my first guess is the tach is not setup right... I will go out and look when it stops raining... I will also do a compression check and replace any fuel filters...
She was running real smooth with no trouble accelerating or idle...
Judging from the way the motor ran, my first guess is the tach is not setup right... I will go out and look when it stops raining... I will also do a compression check and replace any fuel filters...
She was running real smooth with no trouble accelerating or idle...
1999 Voyager 21' Express Fish triple toon 115hp Mercury (SOLD)
2004 Ford F150 SuperCrew
Boise Idaho
2004 Ford F150 SuperCrew
Boise Idaho
- bug73
- Site Moderator
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I was running at about 4900 RPM with my 14 pitch prop. Switched to a 13 pitch and my RPM went up to about 5400 or so...right where I wanted it. I think my engine is rated for 5550 RPM. I did not want the posibility of letting someone else drive and over rev my engine or if I was distracted, I did not want anyway to over rev it so
Ok, I just went out and did a few checks..
I removed the tach and the arrow in the back was pointing to 5, since the range was 1 thru 6 I assumed it was based on the number of cylinders and switched it back to 4... This may be the reason my rpm were not right??
I did a compression check (dont know if I did it right) but after 5 cranks with the other plugs out I was getting up to around 110 psi on each cylinder.. Seems low but they were all the same so that seems like a good thing?
The spark plugs were pretty fouled looking so I will replace them prior to the next outing...
Then it started raining on my so I had to put the cover back on!
Anyone have any comments on my action?
I removed the tach and the arrow in the back was pointing to 5, since the range was 1 thru 6 I assumed it was based on the number of cylinders and switched it back to 4... This may be the reason my rpm were not right??
I did a compression check (dont know if I did it right) but after 5 cranks with the other plugs out I was getting up to around 110 psi on each cylinder.. Seems low but they were all the same so that seems like a good thing?
The spark plugs were pretty fouled looking so I will replace them prior to the next outing...
Then it started raining on my so I had to put the cover back on!
Anyone have any comments on my action?
1999 Voyager 21' Express Fish triple toon 115hp Mercury (SOLD)
2004 Ford F150 SuperCrew
Boise Idaho
2004 Ford F150 SuperCrew
Boise Idaho
- HandymanHerb
- Site Admin
- Posts: 14315
- Joined: Fri Mar 17, 2006 8:57 pm
- Location: Orlando Fla
As long as there close to each other, you should be alright, and yes tach set to 5 would put your tach off a little, rain what's rain, my grass turned to dust a month ago.
But if I still had a grass cutting service like I had a few years back, it would have been raining to beat the band.
But if I still had a grass cutting service like I had a few years back, it would have been raining to beat the band.
In Memory of John 6x6 Larsen
Ahhhh, good advice... I went to the Faria website and downloaded some tach instructions earlier but they must have been for an outboard motor! I just went back and looked again and for the inboard motor your are right, 12 pole and electrical pulses are 1/2 the number of poles so six is right!
Thanks!! This one answer has made building this forum worth it...
Thanks!! This one answer has made building this forum worth it...
1999 Voyager 21' Express Fish triple toon 115hp Mercury (SOLD)
2004 Ford F150 SuperCrew
Boise Idaho
2004 Ford F150 SuperCrew
Boise Idaho