How BAD is this???

[Slayer33]

I bought a used 1998 Nissan 9.8 2-stroke last week. It came with a new spare prop, but I found out that the spare prop doesn't fit.. it was made for a Nissan 9.9. Its physically just too big.

The prop that is on there (I'm still new to outboards) looked pretty beat up, I used it this past weekend and it works.. I just don't know if it could work better or not.. I clocked myself and a friend on a speed app on my phone and we were going 14mph. I'm coming from a 2.5hp 4-stroke so to me this was a huge increase in speed.

The issue here is the prop thats on there...It looks like the wear isn't natural in my opinion.. it looks like the previous owner filed it down or something.. and did a terrible job in doing so..

Can you guys have a look and let me know what you think? Should I replace it? I was able to get on a plane with my 12 foot SIB with about 500-600lbs loaded into it.. but it took seriously probably a good 15-20 seconds to get above the water.. I want a better top speed, be able to take my small family out for joy rides, but also I like to troll when fishing.. I see 2 prop options for my motor in the manual.. a 8.5x8.5 (supposedly for lighter boats) and a 8.5x7.5 (which is currently on there) supposedly for heavier boats.

Help?

 

[ondarvr]

You should have it fixed, but don't expect a huge difference in performance. You will need a prop in good condition before you can dial in a prop for your needs.

 

[bruceb58]

A prop like that is out of balance and can ruin your lower unit bearings. Replace or repair that prop.

 

[Sea Rider]

A 9.8 and a 9.9 OB's are two different horses with 2 different props as you have found out. If wanting top water performance with any load up to some extent, buy a Hardline hour/tach model [FONT=&quot]HR-8061-2, check Iboats, Amazon and install it per instructions. Before dialing other prop, need to test current prop which would not be an issue if beaten up as long it doesn't have bent blades. Go for a wot spin lightly loaded, well trimmed, with top air inflated sib and check achieved max wot rpm, that OB revs 5000-6000 rpm.

Depending on the wot run numbers can maximize 7 different props for your current boating application, one issue is dialing a prop for solo boating while lightly loaded other for 2-3 up, in both cases at max wot rpm. Post results as lightly loaded and with 2 up or as you plan boating with. Testing props without a tach could result in a blind purchase throwing money into the deep blue.

Happy Boating[/FONT]

 

[Slayer33]

Thanks, I've ordered a new prop to get a baseline.. will look into the tach as well. The shop near me had a solas 8.5x8 for cheap so I figured it would be better to have a prop in good shape before I start looking into different pitches etc.

 

[Sea Rider]

You can get a baseline with current prop, better stop purchase, tach that prop and go from there dialing other pitch, but will need achieved wot rpm numbers to pass onto next one.

Happy Boating

 

[Slayer33]

The Hardline tach is pretty expensive to get in Canada.. around $50-60.. would any tach/hour meter be ok? I found this one on amazon

 

[ondarvr]

Check eBay, you can get them for even less, plus free shipping.

 

[Sea Rider]

Check same model at Amazon, don't go for the real cheap chineese ones, need accurate rpm readings and need to be firing sequence programmable or won't read well. Cheap could turn out expensive.

Happy Boating