Would a K&N filter require a re-jet?

Yes a K&N flows alot of air. I recently put a K&N on a vtr250 that already had a dyno jet kit installed, I had to tape over the extra holes drilled in the top of the airbox cover to get it to run. Thats a quick easy fix, eventually I'll buy larger jets and open it back up.

depending on bike you would need a minor setting change move needles up one notch like with a mikuni or kehin carb

harleys are similar.

aircleaner change and minor pipe doesnt require a drastic change on most bikes.

tape over the carb is not something a "repuatable" or good repair guy does.thats really hack....

it indicates that too much air is getting in and the fuel setting either on the float or jets are way off.

main thing with any bike with multiple carbs is getting the carbs sync in all carbs must open and close together.

so, in a nutshell

1 carbs dont need major work

2. tape is hack dont go back to that guy

3 find another mechanic or buy a manual if you are mechanically inclined

4. Cost. this mechanic may cost you a bundle as he IS incompetent.

5 Try to give exact and specifics when asking general questions as this really helps.

Example:

1990 Harley sportster stock engine xxxx miles has drag pipes, k&n filter mikuni 40mm carb etc etc etc

1990 Honda Goldwing stock 1200 cc engine stock exaust stock carbs etc etc etc

good luck

Hi, got a Kymco ZX50, after warranty, I had the dealer try to do some mods, K&N filter, rejet, couldn't fit the exhaust so they gave it back to me with out putting the stock jet in. Bottom line, if you change your filter,you change your jets, and exhaust, all 3 must match or you slowly start frying your piston(too rich or lean) check your plug after 20 or 30 miles and you'll see what I mean. Cost me 1100, to learn the hard way, and I got my advice from Kymco Racing after the jack was spent. google mopedhospital for all the info. all 3 MUST match" or the bike gets it"

Fred

Yes, after putting K&Ns on mine, I could really see a difference. Sounds like they've screwed you. You should rejet after mods. You can do it yourself. If you're not sure it's needing rejetting, then put new plugs in and ride your bike for a few minutes and recheck your plugs, they should be a nice chocolate brown. You don't want to run it too lean (for sure) or too rich. We've got different sized jets so they're available when we need them (season, altitude, the ground we're riding on, etc). People can tell you what size jets you need, but everyone's different, if depends on the altitude, your mods, your bike, etc, so don't go by what someone else uses unless you know someone who rejets theirs often who lives around you. Jet's cost around $5 each. I get mine off eBay and have gotten 2 boxes of different sized jets so we've got a nice variety.

The air filter alone should not require a rejet should be the same as new air filters. But add your pipe and you need to rejet

I recommend a stage 1 jet kit if you want to keep the filter. It's a mild modification if you want a lil more kick.

Shawn

1998 R1

38,000 miles