Test Wheel

[55Crestliner]

How and why does one use a test wheel?<br /><br />Do you use it to see if your motor will make the propper WOT rpm? Or is it just a way to test under load?<br /><br />Example - my motor is doing X rpm with a given prop. Maybe with this same setup, if engine wasn't running it's best it should do a higher rpm?<br /><br />Does the test wheel show condition of tune is what I'm asking.

 

[Laddies]

Re: Test Wheel

The proper test wheel will show engine preformance, how ever they are not availabe le for all models and brands. What are you running?

 

[55Crestliner]

Re: Test Wheel

1955 25 horse Johnson. There is one on ebay that apears to be the right one. But it says it's for other motors also.<br /><br />It would seem that if you put the same wheel on two sizes of motors, the bigger one will put out more rpm, regardless of state of tune.<br /><br />My question is do these show if you're getting propper WOT rpm, or are they strictly just for tuning under load?

 

[55Crestliner]

Re: Test Wheel

The proper test wheel will show engine preformance,

How? by doing what?

 

[rodbolt]

Re: Test Wheel

because the manufacture of the engine specifies how much RPM the motor will turn with the proper test wheel. I love them.<br /> easy and quick and when your done you know if the motor is capeable of turning up like it supposed to. it quickly eliminates prop and hull issues from engine issues.<br />we will take an OX66 yamaha 200 hp for example, guy brings it in, I have never ever seen his rig. he says it runs great and is problem free he just wants a trune up.<br /> thats the first clue I have he is lying . anyway, I tune it up and do the required maint, install the test wheel that yamaha specifies, YB1626. then I look at the RPM specs that yamaha publishes for that motor/test wheel combo. its 5300-5500 RPM. I back it in and spin it up. wow its sits at 5500 RPM and its miller time.<br /> monday the guy calls up raising caine that his motor wont turn but 4500 and his bar buddies all tell him I messed it up.<br /> he shows up, I reinstall the test wheel and back it over, it spins up to 5500RPM just like its supposed to, I bill him another 75 dollars for the hour then go hunt for his prop/hull issue.<br /> sounds like a farce you say? happens at least twice a month.<br />the IDC 2003 DYNO is another nice tool

 

[55Crestliner]

Re: Test Wheel

Great info. So, if I found a test wheel that's supposedly for my motor, but it's listed for others too, how do I know what rpm MY motor should do? Obviously a test wheel that fits my 25 horse 1955 Johnson will also fit a '57 35 horse. But that 35 horse should be doing a much higher rpm, right? SO, where do I find what rpm mine should do with this wheel? Does the manual say this? (if so, I haven't found it yet).

 

[rodbolt]

Re: Test Wheel

if its an OMC test wheel and its listed in the tool manual in 55 then someplace in the OMC service manual the correct RPM will be listed. if not hunt for a spot about the middle of its rated rpm.