Back up prop

[ed72vette]

I am looking for a extra prop for my 2cyle 90 hp 2004 Yamaha. I want this as a back up and maybe to try another pitch. If you go on E-Bay there are non Yamaha props that are for sale that say they will fit Yamaha. If I purchased a non Yamaha prop, how do you know how it should shimmed to fit properly. Is there a place that tells you how to space it out for a Yamaha motor?<br />Ed

 

[Steamboat]

Re: Back up prop

Have you considered a composite prop from West Marine or Boaters World? These are inexpensive props meant to get you home if you need it (if your running a SS prop, remember to get a larger pitch for an aluminum or composit prop). By buying new, you know exactly what your getting and what spacers you need for your engine.

 

[walleyehed]

Re: Back up prop

(if your running a SS prop, remember to get a larger pitch for an aluminum or composit prop).

If running an SS prop, you need to go to a LOWER pitch in alum or composite (due to lower efficiency) to keep the RPM range correct, although the quality of SS prop can turn this around in some cases, if it's a wanna-be SS prop.<br />There are 2 sizes of shafts we deal with on this size of outboard...13 and 15 spline. Alot of the Yamaha and Merc props are interchangable. You may need to research the P/N if given and post back.<br />There are tons of props built for many applications, some require different thrust washers, some don't. If they do, it's no big deal to obtain the right washer.

 

[ed72vette]

Re: Back up prop

Thanks for the good advise and quick response. I have purchased a prop already that is 15 spline and has a dia. of 13"and a pitch of 19 [original is 13.25 X 17] I am not sure of the manufacture, but in doing some measurements, it looks like the dimension form the rear of the prop to the front of the hub is the same as the original prop with the original spacer. I am not sure of the critial measuring points that need to be satisfied. Am I looking at this incorrectly or should ther be some rules to follow to make this or any other non original prop fit correctly. Any information regarding proper prop fit will add to my education and would greatly be appreciated. Thanks in advance for any help.<br />Ed

 

[gary_mirren]

Re: Back up prop

Hi, I bought a composite variable pitch prop from www.propulse.se and have enjoyed mucking about with the settings. From the "first" torque it pulls my boat on the plane almost instantly. From the largest pitch my boat takes ages to get on the plane but the top speed is grin inducing (43MPH on GPS) against a former top speed of 37MPH with ally prop.

 

[gary_mirren]

Re: Back up prop

Originally posted by gazGB:<br /> Hi, I bought a composite variable pitch prop from www.propulse.se and have enjoyed mucking about with the settings. From the "first" torque it pulls my boat on the plane almost instantly. From the largest pitch my boat takes ages to get on the plane but the top speed is grin inducing (43MPH on GPS) against a former top speed of 37MPH with ally prop.

 

[gary_mirren]

Re: Back up prop

DOH! I have a 1976 Glastron GT150 with a 1985 70HP Yam outboard mainly used for wakeboard and ringo fun on Loch Lomond Scotland.Hope this helps.