str8 headers on 550 maxim atv?

i want to just run headers, will this decrease performance of motor? does it sound like crap when you get on the throttle?

 

It will be WAY loud and will make the engine run very lean. Lean means it will run like crap and have reduced performance.

 

RICH usually runs like crap, LEAN usually runs like a raped ape and then BOOM...no more pistons

 

Lean runs good at the middle of the rpm range. They usually dont start or idle worth a crap, and cut out at high rpms. Also they tend to pop like a harley when you close the throttle on deceleration.

 

"zoomies" will run like crap until mid-top rpm, assuming your jetting is good. down low it will sound like poopy in my opinion.

straight pipes into one 2 1/4 or 2 1/2" pipe would make it a little better, and help the scavenging a little more. 2 1/4 pipe would bring the usable power in a little sooner on the rpm range.

 

sorry if i sound like a dumbass, and maybe you have answered my q allready, but im still not sure what i can do if it isnt up to my par when she runs.

 

Shooter's gonna be sooooo jealous! !

Since you don't care about mileage, you go huge on the jets.

Go up about eight numbers. You did get a GIANT rear sprocket- - right?
If you geared it "normal" you built a 120 MPH ATV !!

 

Be prepared for LOUD like you never heard LOUD before. One of my 550's came with an old Kerker 4-1 on it with NO BAFFLE and it was so ungawdly loud you could hear it from two miles off, literally. I was embarrassed to ride it until I got it back to stock. And it wont run for sh*t except in a very narrow band, but IN THAT BAND it will haul. As TIMEtoRIDE suggests, you will need to jet and gear for it or it will be way too dangerous to ride.

 

no, i have a smaller gear then what was on the 550 axle. i have a like 38 tooth that came off the polaris 250 axle. whats wrong with a 120 mph atv?lol

 

can anyone point me in the right direction for either 4 into 1 or 2 into 1 exzaust? i just baught the down headers for the motor, so i just need to either modify it, or just buy from the collector to the muffler. i do still have the origional collector and exzaust from maxim. can i use that?,,, wont my 2 back tires be in the way?

 

It's not gonna pull. At all. The stock 550 rear sprocket, geared for a STREET bike was 45 or 46T. You geared it WAY taller, it won't pull that kind of top end even on the street. With the stock 16T front sprocket and a 38T rear, it won't get out of it's own shadow. You can't go any smaller on the front sprocket, you're gonna have to go big on the back or it simply won't work. You can't simply repeal the laws of physics if they don't suit your ideas.

 

ya, i found a cb900 converted into a quad, these guys and my parents steered me away, even though i thought i looked nice..... guy never did get a hold of me

 

You were right.

 

Loolagigi- - Fitting the stock collector sounds like the easiest fix for now, then add 2 shorty stubby glass packs and you're done.

And we're all dying for pic 's!

As for the gearing, if you have a short enough rear tire, like seen on racing 4 wheelers, then you're not so far off. Tell us the tire height.

Another problem is cooling- - when the street engine is going 45 MPH, you are at light throttle. Plenty of cooling air. The ATV at 45 is pulling more weight with high drag tires. On dirt it's full throttle, hard brakes, full throttle non-stop until you're out of gas. Dirt bikes have 2-3 inch fins, street bikes have 1 inch fins. Careful not to cook the motor.

 

thanks fitz. can you recomend what i would need for the rear sprocket? maybe send a link? how do you feel about the exzaust issue? and who is shooter, and why would he get jealouse?

 

PICS NEXT WEEK FOR SURE. ..... i have a 9" rim with a 16" tall tire on the rear. they look like golf cart tires. not alot of tread.

 

the gearing should be good, the quad tires are much smaller than the bikes was. it will be fast, but it has plenty of power for it!

with higher flowing exhaust you will need to jet bigger as previously stated. it will be insanely loud with straight pipes, i rode my 750 with just a 4-1 header, and it had the voice of a formula caar with the volume of a top fuel dragster! and with that setup, and proper jetting it was sluggish until 6000rpms then it would RIP my arms out. kinda cool!

 

well am i not going to move out of my own shadow, or rip my arms off?

 

If your neck is a little red, you can weld the 46T sprocket onto the 38.

You can saw a glasspack in 2 and cap the ends, then put a 3/4 inch hole in the endcap for cheap-effective mufflers. Make it louder by adding a second hole that you can plug or even adjust.

Shooter 's the intern here.

 

It sounds to me like you won't pull your arms off, just that (with enough take off room) you'll have a top speed of ~120mph.

Top speed is inversely related to acceleration. With a given engine, tires, etc you can either have a higher top speed or more 'pull'. Not both.

Think of it this way:

You've got a nut and bolt that needs to be tightened. You can grab the short ratchet and it'll go pretty quick, but you can only get it so tight. You just can't turn it any more.

Switch to the breaker bar, that 2ft long 'ratchet'.

It is so long that you can't turn it as fast, your hand has to move in a wider arc, and thus a larger distance.

But because your hand is so far from the bolt you are able to apply more torque to the bolt and it is now EASY to turn.

I've always wondered why they call them breaker bars: because you can use them to break loose stuck bolts or because you simply break them?