170 pops up ok but doesn't want to put the nose (Bow) down

[HIFLUTIN]

Have been gettin my 170 on the water finally pops up ok but doesn't want to put the nose (Bow) down
Have a 90 Yammy with a Stainless prop 13x19
Any Input?
Thanks

[seabob4]

While tabs would do you wonders, a prop with more stern lift would probably be the way to go.  4 bladers give more lift in the ass end, but would probably be a bit much on a 90, due to increased blade area....and associated drag.

Anybody with a solution?  Besides throwing a bunch of weight forward?

[Blue Agave]

19 pitch seems a bit much for your setup, what's the max RPMs you are getting?

[akbridge]

A 19" pitch seems to be a lot of pitch for a 90.  I had the same problem as you.  I tried a four blade.  It helped other issues.  But the bow seemed a little light still.  I got a set of transom wedges.  That made a noticeable difference.  I can keep the bow down and stern up in a bad head wind.  Trim tabs would be the ideal solution.  But they are mega bucks.  Try a set of transom wedges.  I got mine on ebay for $15 delivered.

[HIFLUTIN]

A 19" pitch seems to be a lot of pitch for a 90.  I had the same problem as you.  I tried a four blade.  It helped other issues.  But the bow seemed a little light still.  I got a set of transom wedges.  That made a noticeable difference.  I can keep the bow down and stern up in a bad head wind.  Trim tabs would be the ideal solution.  But they are mega bucks.  Try a set of transom wedges.  I got mine on ebay for $15 delivered.

What size prop do you have now?
Can you use the wedges with a jackplate?
have heard different stories about that.
Don't really want the trim tabs, want to keep the boat in water & there a pain in _ss growth wise

[akbridge]

I am currently running a 14" four blade.  I lost some top end speed but my hole shot for an old 90 is pretty mean.  I do have to pay attention to my revs when running low on weight.  I am right at the max of my rpm range at 5500.  I run a jack plate and wedges.  I have no complaints.  I will try and take some photos tomorrow.

[HIFLUTIN]

I am currently running a 14" four blade.  I lost some top end speed but my hole shot for an old 90 is pretty mean.  I do have to pay attention to my revs when running low on weight.  I am right at the max of my rpm range at 5500.  I run a jack plate and wedges.  I have no complaints.  I will try and take some photos tomorrow.

Thanks for the reply-Found some wedges gonna try

[akbridge]

Here is how my set up looks.  


Good luck with getting your boat set up.  I am happy with the performance of mine.  The only issue I have is a some ventilation in corners because the cupping is worn off the tips of my prop.  I can stuff the bow into a hard head wind or tilt up and get better fuel economy.

[HIFLUTIN]

Put a set of Wedges on definitely made a difference but still not what I want
Seems like Iam getting about 3900 rpm max
What would be my next step to determine what Prop would work for my set up?

[akbridge]

You need to find a 15" pitch prop to try.  I just responded to you PM.  You are working that yammy to death.  You should be seeing between 5000 to 5500.  You will see about 200 rpm change per 2" of pitch.  What height is your cavitation plate at when you run?

[kraw2]

I am currently running a 14" four blade.  I lost some top end speed but my hole shot for an old 90 is pretty mean.  I do have to pay attention to my revs when running low on weight.  I am right at the max of my rpm range at 5500.  I run a jack plate and wedges.  I have no complaints.  I will try and take some photos tomorrow.

What size/brand of 4 blade prop did you go with. I want to try one on my 170 once it gets in the water and completely broke in. Currently I have a 13 7/8 x 17 OMC SS prop. I am partial to 4 blade props and there ability to keep a boat on plane at slower speeds.

Thank you

[akbridge]

Kraw2: I responded in you thread but it never hurts to repeat the info.  It's a 13.25" diameter by 14" pitch. Here is a link to the prop: http://www.ptprop.com/index.php?page=sh ... &Itemid=46 It is the RXB4.  It's a good all around prop. It can be run higher than a three blade with a jack plate. And it did give me more stern lift to allow low speed planing.  Also reducing pitch generally allows for better slow speed planing as the engine isn't lugging to keep the boat on a plane.  I have found that most prop manufacturers drop the diameter to help with hole shot. You might want to look into a 15" pitch with a 115. I am running about 5450 rpm on my cross charged omc. It's at the max with a light load. But that suits me fine.

[kraw2]

Yes I remember you earlier post now. Thank you. That is the prop I will be looking for.

[akbridge]

If for some reason you are in the central Florida area let me know.  I would be happy to let you try it out.  Same for any else on the forum.  I have developed a good selection of omc props for the 90 hp range.  If any one wants to try something that I have pm me and we can meet up.

[HIFLUTIN]

Hey Found a
STAINLESS STEEL 13.25 X 12-- 4 BLADE
On ebay-whats you opinion
 on that