AIR BOX MODS??

[87gtNOS]

Hey guys, what all is involved in modding an airbox?

Thanks for any suggestions!

[STROKEDYAMAHA]

what motor?

[21XDC]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by STROKEDYAMAHA &raquo;</TD></TR><TR><TD CLASS="quote">what motor?</TD></TR></TABLE>

1997 ProV 150 Yamaha

[87gtNOS]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 21XDC &raquo;</TD></TR><TR><TD CLASS="quote">

1997 ProV 150 Yamaha </TD></TR></TABLE>

Thanks Mike!!

[87gtNOS]

any takers???

[87gtNOS]

Here are the pics of my airbox mods!! I think I used a 1-1/4" hole saw, and it cut through like butter. These are just holes in the (what I call?) resonance boxes of the airbox. Yamaha uses this design to deaden intake noise. You can see another flat piece of plastic inside each. The airflows behind that. Ultimately, I may actually split the airbox (it's glued together!) and remove those.

Along with these mods, I have installed an Excell Tuner, Excell Divider plate and advanced the timing from 23 degs to 25 degs. Main jets are up a little too. Oh, snipped the rev limiter too...I have also included a pic of the stock tuner next to the Excell tuner!
Now running 91 octane.

I have noticed NO loss in bottom end. I also find myself cruising faster, trimmed down!

These mods have me revving 6400 rpm at will! Plugs look great Boat has no problem pulling rpm, even with the motor down (not trimmed up!). Previously, before mods, I could pull 6000pm with the motor shooting a roost!

I have a DAH prepped A40 Tempest prop, 25p. I think I will now play with motor height to see what mph it pulls.
MPH best prior to mods was 67mph (gps)(empty boat). On the average day, it would run 62mph, maybe a 63.
So far without the limiter snipped, and the tach sitting at 6100rpm (trimmed up or down!!) it ran 66.9mph. Trimming did nothing for rpm. AND THE BOAT WAS LOADED, 20lbs of Pike, two livewells FULL, full fuel, 2 people, all gear, including the wife's purse!!
The boat was going faster with the limiter snipped, however, I was too busy driving and watching water pressure and rpm (and concentrating on going straight) to look to my right at the GPS. So no new top speeds to report. It was too windy also!!

This is a 97 ProV 150 on a ZX185c Skeeter!
Enjoy the pics!!

[21XDC]

You need to get a faster prop with more pitch ...

[87gtNOS]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 21XDC &raquo;</TD></TR><TR><TD CLASS="quote"> You need to get a faster prop... </TD></TR></TABLE>

Mike, I have a 25m, and possibly a 27 of some sort to try.

I guess until I try them, I won't know what bottom end I will lose. This is something I am really confused about!

My DAH 25p Tempest should be more like a 26p shouldn't it?
I have been told 25'm' (Yammy props with 'm' designation) were designed for bass boats, to help with bow lift.

Someone going to school me in props?!

[DoktorC]

It doesn't seem like you need a bunch more bow lift (at least when you're alone). There didn't seem to be an excess amount of trim to carry the bow...with a passenger that may change. I'd ask the previous owner how the DAH compared to the "M" with respect to bow lift. Lowering your RPM with pitch won't make you faster just more sluggish out of the hole (unless you start getting beyond 6500).

I'm sure Jordan will be happy to lend you MY 27 after Sunday lol.

PS - lose the hole saw and put the airbox on the bench

[87gtNOS]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DoktorC &raquo;</TD></TR><TR><TD CLASS="quote">It doesn't seem like you need a bunch more bow lift (at least when you're alone). There didn't seem to be an excess amount of trim to carry the bow...with a passenger that may change. I'd ask the previous owner how the DAH compared to the "M" with respect to bow lift. Lowering your RPM with pitch won't make you faster just more sluggish out of the hole (unless you start getting beyond 6500).

I'm sure Jordan will be happy to lend you MY 27 after Sunday lol.

PS - lose the hole saw and put the airbox on the bench </TD></TR></TABLE>

Well Mike, I think we need Bill to give us some answers!


And Rick, you're lucky the prop is not on the bottom of the lake! (I guess we are lucky for other things though).

[21XDC]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 87gtNOS &raquo;</TD></TR><TR><TD CLASS="quote">

Well Mike, I think we need Bill to give us some answers!
</TD></TR></TABLE>

I was in that boat from day one until he sold it to you 11 years later.. I have been in that boat with many props..

The 2.0 gear ratio on the 150 will allow you to turn more pitch and still have a great holeshot. Mark is comming out with a good 3 blade soon... I think a 26-27P would fly on your boat with better handling and less steering torque. That 25 A45 sux steering. I have driven it and would rather use something you can turn left under power.

[21XDC]

This might be worth a peek&gt;&gt; http://www.bbcboards.net...03677

[87gtNOS]

What is done to my 25 from DAH?

[21XDC]

Bill bought that prop used. He did not have it worked by DAH for his boat. He had a couple of 25 tempest A45s. Not sure what one you have. He also has had a few 25M Pro Series that ran extreemly well in stock form. Mark Croxton can make a Pro Series hummm. Not sure if this 26P was done by Mark.

[87gtNOS]

Mike, I do have a DAH prop.....it's got DAH scribed on it. May also have something else scribed on it too, like a code. I will look at it this weekend and drop DAH an email. I would assume they keep track of props.

[21XDC]

I know you have a DAH prop.. I would contact DAH..

262-534-4440 http://dahpropellers.com/

[87gtNOS]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 21XDC &raquo;</TD></TR><TR><TD CLASS="quote">I know you have a DAH prop.. I would contact DAH..

262-534-4440 http://dahpropellers.com/</TD></TR></TABLE>

LOL! You know what I meant!!!!

I also might make a plate to block off the upper water pickup holes. At 6400 rpm, I was seeing good water pressure still, so I will play it out.

[MUSKIE08]

Is drilling those holes in the intake safe to do on a stock motor? will it improve power? i have a 2006 150 carb and i want to buy a phase 2 but money is tight now

[87gtNOS]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MUSKIE08 &raquo;</TD></TR><TR><TD CLASS="quote">Is drilling those holes in the intake safe to do on a stock motor? will it improve power? i have a 2006 150 carb and i want to buy a phase 2 but money is tight now</TD></TR></TABLE>

All my buddies run NO airbox. I have run mine wot down the lake with NO airbox also last fall in search of extra speed!!
Your stock jetting is plenty on the safe side!

[Jay Martin]

I hope you guys are reading your plugs after a cold day run without your airbox, you never can be to careful when it comes to carbed engines..