I jetted my bike for the first time this weekend. Started with a 145 main 42 pilot 1.5 turns on air 2 clip from the top on factory needle. on a 01 220 with a dyno port pipe a d muff air box mod and carbon fiber reeds. The bike never fouled plugs before until I changrd the main. I started with the 140 all eles stay the same the bike had real snap but looked a little lean on the chop so I up the main to the 142 everthing eles the same good power kinda gray black ring on plug I figure be safe richer is better rode the bike for about 12 miles tight woods and bam shut down pull the plug its black allmost like soot so I change the plug go anoyher 5 miles and bam same thing . So how does a leaner jet foul plugs? I am at a loos o NE PA is the riding area
Dave HELP !!!!!
- Thread starter Rich B
- Start date
There was [probably still is] a post on the RZ500 site where a guy did a really comprehensive study of jet number vs. orfice size What he found was that "off the shelf" jets [these were mikuni jets] varied up to 10 jet numbers but still had the same orfice size. He concluded that this was one reason that jetting the RZ500s [4 carbs] was such a chore. One really needs a set of hole gauges to know exactly what we're using.
Canadian Dave
Super Power AssClown
- Apr 28, 1999
- 1,202
- 0
Rich have a look at the card tuning article on the JustKDX web page paying particular attention to what circuit has the most effect at each throttle setting. Check each throttle setting independently, general plug readings aren't going to tell you a whole lot. You'll also want to insure you are using the proper heat range plug before you start the jetting process. Most KDX owners will find the BR7ES is their best choice depending on their riding style and conditions.
David
David
