Plug chop?

Just how long of a run does it take at a certain throttle setting to get a good plug reading when doing a plug chop to determine jetting?

I ask this as the road near my house is kinda busy and full throttle runs gets me on top of another car really fast! Just wondering how long it takes to "color" the plug enough to get an accurate read.

Sonny

with fresh plugs at least a 1/4 of a mile but plugs chops aren't really all that accurate anymore with all the different additives that are in the fuels nowadays you can get fooled the best way to get your jetting right is to invest in at least 3 dyno runs with an air fuel ratio meter plugged in to the exhaust if your interested in mileage try for around 14.5/1 a/f mixture if you want power go for around 13.5 to 1. it really not worth getting tickets or crashing in to someone to check your jetting. spend a bit at a good dyno place up front and it will be worth it. look for a shop that has a dynojet 250 dyno with the econonamy like it is and the time of year you probably can get a deal. make a run if you need to make changes then your in a nice warm shop already make your changes then give it another pull. by the way plug chops can be done at any throttle position but most times you use them to check main jets so wide open throttle is needed.

Thanks, I've been out checking my pilot jetting and need to change it so, I thought I'd try to see what the main was doing before I pulled the carbs again and was wondering how much of a run I'd have to get.

Would like to have a dyno around! About how much is the normal charge for dyno time?

Sonny