How Bigs your Prop on Mercury Optimax 90...

[crabcrusher]

Hoping to geT some feedback from fellow Rockstars and breamanglers..

I have a 2008 Mercury Optimax, to which i am hoping to upgrade the prop, toge a tad more performance... The current prop i have is not stainless and i have had my use out of it...and time to get a new one...

Any info appreciated....

Cheers Nick

[seamonkey]

Questions -

What boat?
What size prop now?
Whats your max rpm when wide open?
Top speed on current prop (if you know)?


S.

[crabcrusher]

Originally Posted by seamonkey

Questions -

What boat?
What size prop now?
Whats your max rpm when wide open?
Top speed on current prop (if you know)?


S.

The boat is a Nitro 640

As for the current prop... Thats a good question, all i know afte a few rockwalls its in need of an urgent makeover.

When wide open she runs at about 5500 rpm, any more for to long the redline alarm lets you know whos boss

The top speed i have got on the GPS is about 85ks

[Stick Minnow]

Definetley need a stainless crabcrusher. i have a 115 pro XS, abit different i know, but we have a 22in pitch on ours, i'd say you would be looking at around a 20in.

Go to the mercury marine website and go to their prop calculator, thats how we got the size for ours.

[tchoklat]

Go to propgods.com and ask Ken. He will need to know;

current prop pitch
current max speed
current max WOT RPM
engine gear ratio
what you are hoping top get - better hole shot, faster speeed etc.

He is the man!

[seamonkey]

Originally Posted by crabcrusher

The boat is a Nitro 640

As for the current prop... Thats a good question, all i know afte a few rockwalls its in need of an urgent makeover.

When wide open she runs at about 5500 rpm, any more for to long the redline alarm lets you know whos boss

The top speed i have got on the GPS is about 85ks

Current prop pitch would be worth knowing. Redline alarm is 6000 rpm as I remember - so if the speedo is showing 5500rpm either the speedo is wrong or its not a redline alarm, its an overheat.

Does it have a jackplate by the way? Seems a lot of picky questions I know but if you want to get it right you need to know exactly where your at now.

[crabcrusher]

Originally Posted by seamonkey

Current prop pitch would be worth knowing. Redline alarm is 6000 rpm as I remember - so if the speedo is showing 5500rpm either the speedo is wrong or its not a redline alarm, its an overheat.

Does it have a jackplate by the way? Seems a lot of picky questions I know but if you want to get it right you need to know exactly where your at now.

Yeah no probs.... I reakon you are right the redline is about 6k.. Its been a while since ive been out for a fish...

As for the current prop... I will have to go and investigate over the weekend, as the boats in storage..

There is no jack plate...

I am not trying to get to much more out of it, but thought if i need a new prop it could be a good time to investigate....

[crabcrusher]

Originally Posted by tchoklat

Go to propgods.com and ask Ken. He will need to know;

current prop pitch
current max speed
current max WOT RPM
engine gear ratio
what you are hoping top get - better hole shot, faster speeed etc.

He is the man!

Thanks for that ill give the site a go...

[funfisher]

I have a 21 pitch lazer on my 75 hp opti and my boats a 4.8 alloy and i get about 5500rpm out of it fully trimmed, i also have a 18pitch vengence that is good for when the boat is fully loaded with people or camping gear but it will redline under the boats usual fishing load. Just a word of warning also that some of the aftermarket non merc props do seem to put out a hell of a lot more vibration through the boat i had this happen with one that i imported from USA.

[crabcrusher]

Thanks guys...there is some food for thought..

Anyone have a spare prop SS they have removed of a 90 optimax, that is sitting around collecting dust?

If so send me a PM, i may be able to get it out of your way

[mojon]

You can also use yamaha props,on your Opti 90hp, they use the same spline !