test propeller

[Searider]

Tried the search function and checked on google .. no success ..
I am curious how the Yamaha test propeller for a 90hp 2 stroke looks like .
Can anybody help ??
Thx in advance !
Jurgen

[YammyMan]

The ones that I have seen are an enclosed circle with blades. Kind of hard to explain if you've never seen one. They are to give resistance to the motor without thrust. I searched youtube for a link, but like you said, not much on the net about them.

[rodbolt17]

search for part number YB-1620 or KL-1620.

[Searider]

Thanks mate !

[99yam40]

If you find a picture post it , as some others may like to have a look too.

I googled those part #s but did not find anything with a pic

[Searider]

I also tried to find it but did not succeed ..
But the good news is - based on the part numbers rodbolt17 provided I found a German dealer who :
- has such test propeller
- will provide it to me for testing
As he said when he tried it it does not apply much load to the engine - but I`ll see .
Ordered today a cylinder head with higher compression ( we got here only good fuel ) & a tuning exhaust .
Before installing this parts I intend to check the max motor rpm with original parts as reference and then I will install the head and the exhaust and will measure again . The head also comes with slightly bigger main jets .
This should show the gain of power . At least I hope ..
This will happen only in spring when I have the opportunity to test the motor .
Will make definitely pictures and will post them !
Cheers

[Searider]

I posted the same question also on a German boat forum . If you scroll down the link you will find some pictures .
Yamaha test propeller / test wheel - boote-forum.de - Das Forum rund um Boote

[Searider]

I posted the same question on a German forum and one of the guys posted today some pictures .
It is in german but if you scroll through the thread you will see them .
Yamaha test propeller / test wheel - boote-forum.de - Das Forum rund um Boote

[Searider]

Strange - tried yesterday twice to post a message with a link to a German boat forum where one of the guys there posted some pictures of the test propeller .
For some reasons these messages do not appear ..

[almetelo]

Never had a problem by post a link here just fot attachments!
Try again I guess...

Is a lot of people waiting for those pics

[99yam40]

might just type the address instead of making a link.

Or click on the picture
copy it to your computer
then attach that pic to this thread in your next post

[rodbolt17]

what your trying to do isnt going to work well.
that test wheel provides a known load on a known gear ratio on a known horsepower output.
if the stock 90 hp is running correctly it can spin that test wheel at 5100-5300 RPM.
if it cannot its sick and needs a Dr.
however max RPM is 5500.
what you need is someone with a dynomometer.

[Searider]

Try now :

Yamaha test propeller / test wheel - boote-forum.de - Das Forum rund um Boote

I agree that it is not a dyno - at our facility we are just installing a 3500hp dyno for CAT engines - but I can check timing at WOT and as for tuning it is at least an indicator that things not going the wrong direction .
I am still thinking to take one of my old alu props and to reduce significantly the diameter to use it as a "test prop" - or reference prop as well .
Just hard or impossible to guess what the right diameter will be ..
Again - I will not be able to test it either in march in France or even only in May in Germany - but I will post the results .
Regards from Ukraine .

[Searider]

try this and put triple w in front ..
was just writing a post but AGAIN it disappeared

.boote-forum.de/showthread.php?p=2984684#post2984684

[Searider]

give up .. wrote another long post but it just disappeared .. probably the KGB steps on the line ..
Agree that this will not replace a dyno . BTW - in our faciltiy we are just installing a 3500hp dyno for CAT engines
But I can do easily the WOT timing test and for the tuning it will indicate at least whether the changes going into the right directions .
I even think about to take one of my old alu props and reduce the diameter significantly and to try to use it as well as a reference prop . Question is only that is is absolutely unpredictable to estimate how much the diameter needs to be reduced to achieve appr 5000 rpm ..
Unfortunately I will be only able to test either in March in France or even only in May in Germany the motor - but I will keep you posted !
Here some pics .
Regards from Ukraine