Topic: Jetting change due to new exhaust baffle?

[1976cb750f836]

I got tired of my old homemade baffle insert in the mac 4 into 1!
I pulled it and replaced it with a stock Mac cannister,with a competition baffle.
It's now a little lean on top? Less restrictive baffle.
Had 125 mains, tried 127.5,improved top,tried 130s,still improving,tried 132s seems to be best?
But as the top improved the roll on at 3-4k got Soggy? With the 125s it really pulled better all through the low and Mid?
So I'm betting I'll have to lean the needle a notch,does this sound right?
THANKS

[BomberMann650]

Try the needle position change.

[veets]

Not to Hijack the thread but I am entertaining the competition baffle
for my MAC and was curious how much louder it was over the standard baffle?


Thx
Steve

[1976cb750f836]

Well I lied Kinda?
I've got a standard baffle,sawed off bout 7-8in from front,20-30 1/4in holes drilled in,packed with coarse steel wool? It's gotta out flow the competition one?
It's really nice,way quieter than. My homemade insert in open Header!
Hardly any louder than std baffle till u get bout 4-5k, then noise picks up,but still nice and mellow?
I rode it bout a mile with std baffle before I modded  it.
And it didn't cost another 49$ just an hour of my time?
And as a bonus,it runs better than when the insert in open header was being used?
The design of the factory baffle can ,and insert ,improves tq and top surprisingly well?
Rode again today,maby 15-20 miles,got it warmed up real good.
Going back down 1 on the mains, then decide on needle?

[1976cb750f836]

Went with the 127.5s, runs well enough.
Going to leave jetting get alone till spring, Temps in 50s now and no humidity.
Don't want to jet for winter when most of my riding will be in 80s,and humidity is usually high in East tn?

[1976cb750f836]

Pics of baffle mod.
I had lost my original canister.
Ran the diy baffle 10 years.
MAC didn't list the canister as parts for sale.
I found this off ebay Bay, it's off a mac chrome 4 into 2 system.
Canister and baffle look same as 4 into 1 canister, except chrome one is 2in longer,
Both 2.5in inlet,3.5 rear, and I had to weld a tab on back for mount.

[1976cb750f836]

Hears the piece I cut off the baffle.
If anyone attempts this mod,be sure to wrap baffle insert with coarse steel wool ,
As much as u can get in,it tie mine in with a piece of wire.
Without the wool the sound is kinda dingie,similar to 2-stroke at low rpm.