Jetting question

[KrustyTC]

I bought a set of stock mufflers off of Ebay and drilled a 1/2 inch hole in the restrictor plate. Can I get away with just an air/fuel mixture adjustment or do I need to rejet? I did this with the Honda Shadow I had before my Sportster and the mixture screw adjustment was all the bike needed to run right and get rid of popping on decel.

I haven't installed the mufflers yet. I'll let everyone know how they sound once I get them installed. It will be a while though as we have about a foot of snow here in Mass. SUCKS big time!

thanks,
KrustyTC

[Doug]

No real need to rejet unless you change the intake side of the house... IN Fact... I've never made any Carb adjustpemts after reworking exhaust setups as I've not had a popping problem... BTW the shorty mufflers have a pressed in plug that can be easly popped out rather then drilling a hole through them... (that is if they were stock mufflers).... I'm running stock mufflers on my XLH1200 with the restrictor plug popped out and no popping problems. NO changes were made to the intake such as jetting... and it all works for me... as it has in the past on other Sports I've had...

[KrustyTC]

Thanks Doug, I appreciate the info. I figured I'd be all set, just wanted to make sure though.

The only reason I didn't punch the plug out completely was that I don't want the bike too loud. My neighbors live kind of close and I leave pretty early in the morning. I figured I'd be better off with drilling, that way if I want it louder I can just drill a bigger hole. If it's still not loud enough then I still have the option of punching out the plug. I'm sure eventually I'll end up replacing the exhaust.

These are stock Sportster mufflers I bought off of Ebay. I got them for cheap too. I'd rather experiment with these instead of the ones that came on the bike. If I don't like the sound of the drilled pipes I can always go back to the stockers.

thanks again,
KrustyTC

[olivier]

I confirm ... try the new mufflers without carb adjustments. Should be no problem.

[KrustyTC]

Thanks to everyone for the information they've posted. That is what I thought but wanted to be sure. Now I just can't wait till the weather is decent enough to install the mufflers! Unfortunately I don't have a garage to work in, only an unheated shed.

thanks again,
KrustyTC

[KrustyTC]

Just another quick question. If I add a K&N Filter to the stock airbox along with the modded mufflers, I'm pretty sure I'll have to rejet then. Any ideas were to start?

thanks again all,
KrustyTC

[kd460]

Can't help you on the jetting, but read your spark plugs! They can tell allot, when I did the K&N and pipes, I did not need to rejet cause according to my plugs, I was running a little rich from the factory. After the swap, nice and golden brown like a roasted (not burnt) marshmallow.


Do a search on "spark plug reading" and download some pics. Do some plug chops, if you do need to change jetting, I don't think you'll have to go to far from stock size. And don't over oil the element when you get the new K&N, thats the biggest mistake people make. Spray it till light pink wait awhile (about an hour) and touch up any spots you missed. Wait a little while longer and ride. Watch the plugs, to rich is to rich, to lean is a cooked piston!!! Kd460