Airbox gutting

[wideopen23]

I have read alot of people say that gutting an airbox on the erudes is a good starting mod. Does anyone have pics or can explain what exactly this is. I am working on a 1989 XP200. Second I am assuming that I will need to rejet for this?
Thanks for all your help.

[BenKeith]

To gut the airbox, you have to remove the screws inside it, this lets you remove the baffle. You will notice the fange on the baffle is also part of the sealing surface so you have to cut the flange off and use it to regain the seal.

Yes, if you remove or gut the airbox you "MUST" replace the main jets. I would suggest going with #72D's in the top four carbs and #74d's in the bottom two.

Let me also say, any time you start screwing around with things that can change the mixture, if you don't know how to read plugs and piston domes, strongly recommend you have someone along that does the first time you run WOT. Make a short 30 second run and check them. These motors will eat pistons like us southern boys eat grits if you lean them out.

[The Big Al]

Get a 10ga shotgun! ( 12ga will do) 10ga better results

Get in the boat, stand in front of the engine!
Aim st the front of the engine where the air box is located!
Pull trigger!

If engine still runs! It will have lot of freash air!
If not, unbolt it and go buy a MERCURY!!!
;)

[wideopen23]

Ben thanks for the help on this. I am sure we live in much diffrent elevations, I think the jets might be diffrent. As a guesstamation about how many do you go up in size for the airbox adjustment?
Thankyou again for your help.
And SS thanks for the tip that was orginal!!!

[1BadAction]

I was going to say, if you wanted to wait, i am going to make some over size carbonfiber airboxes, But these are for my 200 carb'd merc. doh!

[wideopen23]

Thanks stream, I dont think those will work for me. THanks for the offer though.

[BenKeith]

The lakes I mostly run on are no more than 400 ft above sea level and normally the size I said works on them. your motor has 62D's in it now if they have never been changed. So, that's 10 jet sizes on the top four and 12 on the bottom two

[wideopen23]

Ok os go about 10 sizes, thanks. Here in AZ the lake altitude is about 2500 feet above sea level. That is why I asked about how many jet sizes.

[lokinutz]

I assume the 72,74 etc. is thousandths like most other jets? Also what does the "d"mean? Thread size maybe (OD)?

[racer]

The D is for flow direction and while the manual will state a 74 as .074 it is actually larger.

[BenKeith]

Lokinutz.

The number is the size, but on OMC main jets, they don't correspond to the diameter of the orfice. A 72D will actually be closer to .075". The D is a suffice to indicate fuel flow direction. You can buy a similar jet that has a C suffice but it has an opposite flow direction of the D jet and they can't be interchanged.

[wideopen23]

Will I need to rejet the mid or idle jets with the airbox change?
What do you guys think about just removing the airbox instead of gutting it. What are the pro's and con's to this? I dont see any reason you couldnt run without it?

[wideopen23]

So one has to know this?

[BenKeith]

Gutting the air box has no affect on idles and mids.

If you don't mind the mess it makes inside the cover just remove it. Gutting it and putting it back on keeps all the crap blowing back out the carbs confined. Make sure the little siphon tube at the bottom of the box is in place or that waste will build up in the bottom.

[wideopen23]

Thanks for all your help on this. I really appreciate it. I have been trying to look up as many old threads as poss. so I dont ask the same questions others have,
Thanks again