load testing

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
is there a way to load test a motor in a tank<br />or on muffs? have heard of a special prop but<br />was wondering if there was a way to simulate<br />load in the water when your not....<br />thanks in advance,<br />M.Y.
 

Scooby

Seaman
Joined
Jun 25, 2002
Messages
50
Re: load testing

yes....I saw one on overtons.com that muffles the noise and creates back pressure, just what your probably looking for. It attaches to your existing prop so it looks like an easy hookup.
 

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
Re: load testing

that's why you ask... they're always coming up<br />with new stuff. :cool: <br />know what it was called?<br />anyone else heard of these?
 

Scooby

Seaman
Joined
Jun 25, 2002
Messages
50
Re: load testing

Took me a few tries but I found it for you.<br />Go to: overtons.com<br />click on: Boating<br />click on: Parts<br />click on: Engine parts<br />click on: Engine flushers<br />Bottom left of the page, "Flush muffler" $42.99
 

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: load testing

mellowyellow, what GT150 is referring to allows QUIETER running on a hose, but NOT load testing. You are referring to a test wheel, which allows SMALL motors only to be tank run at high power. There are only two other methods to run a motor at high power settings: a dyno or on the water. A dyno is a very expensive piece of test gear and most shops don't have one unless they are pretty far from the water.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: load testing

That will act as a muffler and create the wall of water in the mid section but it will not simulate a load.<br /><br />You can do the same thing with the bottom of a plastic milk jug.<br /><br />Good luck!
 

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
Re: load testing

boy I'm sure glad everyone agrees... :p <br />after looking at it, I'm not confident.<br />has anyone out there ever tried one of these?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: load testing

I guess I'm not stating myself clearly.<br /><br />It will NOT, repeat NOT simulate a load!
 

Scooby

Seaman
Joined
Jun 25, 2002
Messages
50
Re: load testing

I re-read your original post and I must have read it wrong, the part I refered you too will only create back pressure to properly flush out the system that's what it was designed to do, It will not simulate a load. So disregard my postings and go with the Admirals advice. Sorry for the confusion. It must of been the six foot roller I took over the bow this weekend when a nasty storm snuck up on me that still has me a little shaken.
 

FreeBeeTony

Captain
Joined
May 15, 2002
Messages
3,991
Re: load testing

Dhadley, what do you mean by "the wall of water in the mid section"? Are you talking about the mid range operating point?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: load testing

No. When an outboard is sitting in the water there is water in the mid section or exhaust area equal to the water line on the outside of the motor. This creats back pressure and this is why motors idle higher out of the water than in. Some are very different in and out of the water.<br /><br />The muffler will cause some water to back up in the mid section thus creating some back pressure. It may not be exactly as in the water but it will be close. Besides, it takes that sharpness out of the noise and makes it somewhat bareable.<br /><br />Hope that helps!
 

FreeBeeTony

Captain
Joined
May 15, 2002
Messages
3,991
Re: load testing

Thanks Dhadley, thats what I thought you meant. When making this muffler out of the bottom of a milk container (as you mentioned), should it fit snuggly aroung the center of the prop as to not let any water out?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: load testing

All I do is cut the botom off about an inch or so up. Does not matter really. Then I cut an "X" in the center. I remove the prop and the forward thrust washer. Slip on the plastic over the shaft. Shove the prop back on without the washer. Hand tighten (snug) the nut and start the motor. <br /><br />My neighbors are much happier now.
 

FreeBeeTony

Captain
Joined
May 15, 2002
Messages
3,991
Re: load testing

Think it could be done over the prop so the prop doesn't have to be removed? I like to flush after each time out......I'm in salt water, if I have to remove the prop each time that will be a pain in the a##!.......
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: load testing

Baker Marine Support makes a muffler that goes on without removing the prop. (They also make a metal version of my plastic deal) It doesnt quite stop the noise as good and lets some more water out but yes it can be done. <br /><br />In salt water like to take the prop off regularly anyway to grease the shaft. <br /><br />Good luck!
 

R. Wood

Seaman
Joined
Jun 10, 2002
Messages
53
Re: load testing

Where can you get the test wheels?<br /><br />Do the test wheels need to be submerged to achieve proper loading (as opposed to, in combination with muffs)?
 

mar t G

Seaman Apprentice
Joined
Jun 28, 2004
Messages
38
Re: load testing

dhadley is the milk jug muff just for flushing or are you leaving it on and why is there so much talk about using the proper test wheel ? amazon .com says the words listed in my manual 20 time and there's even a table with test wheel part number as well as rec. RPM'S but everywhere i try to look for one i come up MT<br />i know this site does a wonderful job of keeping us out of the shop and some of our money in our pockets but some times you need to have a pro look at it and it seams to me that just having the timing checked and set couldn't cost you much more than buying one of those elusive test wheels know ones ever seen
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: load testing

The test wheels simulate a load on the motor so you can check timing, carb mix, ignition etc at higher rpms without actually zipping across the lake hanging off the back of a boat. <br /><br />We do the same thing by backing down the ramp and running the motor while its still hooked to the trailer. Especially a race boat. Can you imagine hanging off the back of a Mirage tunnel boat at 110 mph?
 
Top