Need Advice
 

I just bought a 99 SH with 8486 miles on it from a buddy. I am new to the SH but not new to crotch rockets. I have noticed that the bike has a stumble or a hickup between 2000-4000 rpm range. It only does it when I keep it at a constant rpm like 3000. It is getting worse the more I ride it. It is starting to sound like a miss from the exhaust. I put plugs in it and did not change. It has carbon fiber two bros cans on it. Does it need to be rejetted and when I let off the gas it backfires alot. Thanks for any help

good choice! welcome to the forum that never sleeps.

get ready to sell off some of your superfluous fire-power at the next gun show so that you can afford to fix this bike! heh. just kidding.
1) pray that your air-box is still OEM.
2) see this thread for preliminary, non-invasive maintenance that may decrease or eliminate the misbehavior:
https://www.superhawkforum.com/forum...b-issue-25460/
3) if '2' doesn't fix things, you probably need to do some research on the 3000RPM mid-range "probably running too rich" carb jet adjustment and/or main swap-down, etc. there are plenty of fascinating carb threads that go into details that will assist you in your new quest at tweaking the big-ass carbs on your new bike.

--fred

Thanks for the advice. I just pulled the air box off and checked the plugs and the plugs look burnt. They only have about 100 miles on them. I am thinking that it is dumping alot of fuel. One question, What are the 2 foam filters on the front and back of the air box? I touched 1 of them and it feel apart. O yea it is the oem air box.

Check your air filter. If it's not stock, that could be the problem.

let me see. those two foam filters are... god, i donno. i think they are filters for front and rear cylinder-head breathers. don't feel bad. i had a spare hanging in my basement for a couple of years. when it seemed like a wise idea to replace the extra grungy one, i opened the package and the replacement filter crumbled. so i cleaned the ones i had with kerosine, let them dry and oiled them and they're happy as ever. i'll bet that someone in this list has described how they fashioned their own out of lightweight neoprine or foam rubber.

you know what you REALLY need.?! you need a shop manual. what's that phrase, again? ...oh, "driving while blind." there's a link somewhere in this space to a pdf file that is The Shop Manual. look for it. or order one. it'll not only make your day... it'll make your month, your year.

good luck!

--fred

#1 the pilot jets are clogged, the bike has sat for a looooong time and needs the carbs removed and cleaned.

#2 The foam filters feed filtered air to the back side of the diaphragms in the carbs. Make sure you have them in there when you are running the bike or you will be looking for a new set of carbs after you suck dirt into them.

#3 Here is your one "search" freebie..... https://www.superhawkforum.com/forum...-manual-11365/

Thanks alot guys. Let me see what I can do with. I ordered a new oem air filter, it should be here tuesday.