Velocity stack

**FORBESAUTO** · 10-19-2019, 09:38 AM

You can use a 2.5 box also, just ain’t as purdy being plastic, but functions the same. If ya use the plastic one, you’ll need to make inserts to go inside the stems where bolts go through to bolt to carbs. Otherwise it’ll loosen up due to plastic slowly collapsing over time. I’ve used pieces of brake tubing cut to length. You may have to slightly drill the plastic to accept the O/D of the tubing, can’t remember, but works well. Also use a dab of loc-tite on bolts

**eli** · 10-19-2019, 09:44 AM

Spacers didn't work very well on my other 245's so I didn't do them on my ff blocks

**mrichartz** · 10-19-2019, 10:43 AM

Oh if not running the airbox and don't want crap getting in carbs.. frogskinz over the air inlets on cowl then use a wire mesh over it to hold it in place..
I just make sure to blow the pan out when I've had it off or worked on it.
I'm paranoid so I still keep them covered...
Had them for 15 years an never covered them
But when I got the powerheads and stuff from
James Perry nit taking any chances

**nitro_rat** · 10-19-2019, 12:20 PM

Originally Posted by Merc 2.5

and I make sure the inside of the bucket was and is clean b4 I run it

I use a wire wheel on a die grinder to make sure ALL the foam is gone inside my cowls!

**mrichartz** · 10-19-2019, 01:50 PM

Do a search on here I saw at one point someone made a box(I think he used two and cut them up to fit but don't really remember) with a gasket that sealed to cowl and closed of the carbs from the rest of underneath with vents on the front looked really good
Not sure what cowl he had tho was a merc..

Or get a diaper and tape it to the bottom.. lol

**Merc 2.5** · 10-19-2019, 02:04 PM

Lol. Well nitro rat has or had a cowl I been wanting to get , maybe I should just go that route ,then have plenty of room

**Merc 2.5** · 10-19-2019, 06:33 PM

I no we all been reading Randy's (wildman) bout new 450 and I know its apples to oranges. but he gained what 3-5mph with ram air cowl? Seems like carb mota would have same kinda effects. Takin in account port work compression etc. Goin from stock fishin cowl (suppose b well insulated) to lightweight bp or 260 type cowl that will flow little more air. Idk just thinkin out loud again.

**mrichartz** · 10-19-2019, 07:05 PM

Originally Posted by Merc 2.5

I no we all been reading Randy's (wildman) bout new 450 and I know its apples to oranges. but he gained what 3-5mph with ram air cowl? Seems like carb mota would have same kinda effects. Takin in account port work compression etc. Goin from stock fishin cowl (suppose b well insulated) to lightweight bp or 260 type cowl that will flow little more air. Idk just thinkin out loud again.

I would say yes if you have all the other work done.
It won't hurt.
I know it made a difference on mine
I know if you start talking on here people argue(and I'm not going to argue) that opening cowl taking airbox off drilling lower for exhaust Doesn't do anything except noise (would say if you just drill exhaust not going to do much by itself)
I've done it on my all my Evinrudes but also jetted up alot
And there is a Difference..
When I did airbox,jets and drilled lower and waited to do louvers etc you can tell the difference..again not saying it's huge but definitely noticable
And with my new powerheads with all the work done it

**Merc 2.5** · 10-19-2019, 07:45 PM

Originally Posted by mrichartz

I would say yes if you have all the other work done.
It won't hurt.
I know it made a difference on mine
I know if you start talking on here people argue(and I'm not going to argue) that opening cowl taking airbox off drilling lower for exhaust Doesn't do anything except noise (would say if you just drill exhaust not going to do much by itself)
I've done it on my all my Evinrudes but also jetted up alot
And there is a Difference..
When I did airbox,jets and drilled lower and waited to do louvers etc you can tell the difference..again not saying it's huge but definitely noticable
And with my new powerheads with all the work done it

Exactly what I'm talking bout. I bout guarantee we have same kinda mota work comin from james ,besides the merc and everslowrude hahahlmao. Just kiddin. But yes. Everything adds up in the end!!

**Motv18** · 10-19-2019, 08:15 PM

Rear induction is hotter as the air flows over the block to get to the carbs.

And rams ir scoops do work just gotta be going fast enough. Over 150mph you will actually start to build boost.

If if you did a scoop and piped it into the carbs you would probably gain from cool air and wonce moving good the ram effect should be faster.

But it is getting it all right and good that’s hard.

Sounds wishywashy I know. Perhaps I should state it as done right yea, done bad boo

**powerabout** · 10-19-2019, 09:15 PM

Originally Posted by FORBESAUTO

.

very nice!

**nitro_rat** · 10-19-2019, 11:12 PM

Originally Posted by Merc 2.5

Lol. Well nitro rat has or had a cowl I been wanting to get , maybe I should just go that route ,then have plenty of room

Maybe still have it, which one?

**Merc 2.5** · 10-20-2019, 05:15 AM

Originally Posted by nitro_rat

Maybe still have it, which one?

BP cowl

**tux974** · 10-20-2019, 05:35 AM

Originally Posted by nitro_rat

That's what I said, you can make a 2.4 air box (maybe a 2.5, I've never had a factory carb 2.5) look like this:

Attachment 451126

Merc 13443A1, NLA

Those Powers stacks are sexy though!

I have made these, just for looks!
But again very important to make sure your pan and cover is clean! I would suggest to check every time out when running open carbs!