re jet

[rooster400ex]

i just put on my hmf slip and i wanted to know if running without re jetting can hurt

[Rip_Tear]

Yes is can hurt, if you're running lean you are likely to do damage to your motor. Running rich doesn't really hurt your bike (more gas then air). If you are back fireing then, or your plug is white when you take it out, you need to jet bigger. Check the How-To's for more info.

[rooster400ex]

how can i tell if its lean or rich

[Rip_Tear]

if it's lean the plug will be white, if it's rich it will be black, and if it's just right it should be brown. This is the center part of the plug (sparking end), when new it will be white porclin.

[Def-e-nition]

What if the bike is running Rich ( plug Black) , you dont install jets , and you install an HMF ?

Would that level it out , or would jetting still be necessary in order to get it "right ?"

Im being pushed into jetting , not that im against it , but i would assume that if the bike is currently running rich , that by putting on a slip-on , the mixture should lean out a little ? Or am i just plain nuts ?

We have a local guy making something down the same vein as Hmf , and with it - he wants to sell me the kit . My problem is access to a dyno . i would've bought from the dyno guy , but then i saw this other pipe , decided to take one - and cut myself out of ever being able to slip the bike onto his dyno ever again ..:(

So - If i Buy the jet kit- will i be able to dial the jets in pretty accurate , or will i simply be towing the line in taking the kit ??

[400exstud]

You will still need to rejet it because it will go from being too rich to too lean. Your supposed to change jets even from winter to summer although most people don't.