My friend has a 250ex..with a new FMF muffler. He wants to get his engine re-jetted...but my other friend says you should wait until you get a little more engine mods? Is there a specific number of mods when you should get it re-jetted, or is it how long you own the quad, or is it when you feel like it. Thanks[img]i/expressions/face-icon-small-happy.gif[/img]

 

Once you get a pipe (full or slip-on) you should rejet. Even with a new air filter or air box mods sometime rejetting the carb is necessary.

 

You rejet when you need it. Most of the time mods will warrant that, but not always. So don't just rejet because you think you need to, rejet because you know you need to. Reed the plug and see if it is running lean.

 

I agree, after you change a pipe (full or slip on, either way)- make any airbox mods, or change to a different filter, chances are the jetting is going to be off a little. Pull to plug to know for sure which way you are; rich or lean and rejet accordingly. Jetting is a larger issue on a 2 stroke bike, but can be a significant issue with a 4 stroke as well.

story time: I put a fmf gold series pipe and powercore silencer on my 250r, it ran like a$$ until I rejetted.

 

i agree its not going to run good until your friend jets it.

 

You can just check your plug. I know a kid around here with a z400 and he added a full yoshi system, k&n and no lid and he says ur not supposed to change the jetting[img]i/expressions/face-icon-small-disgusted.gif[/img]

 

lol thats bs

 

ops wrong quot, i ment to quote yellowexracer on how that kid with his z400 didnt need to re-jet

 

So how do you gain power from that. Your flowing more air but sending the same amount of gas into the cylinder as if it was stock. If a company tells you that you shouldnt have to rejet after installing there pipe, dont buy it. Its like going out and buying this really fast computer and but using a 28k modem for the internet.

I think that kid is alittle off, all the yoshi systems ive seen give you instructions that tell you what jets to put in.

EDIT: I understand that running alittle lean can give you more power but that cant hurt the engine. Only way i dont see someone rejetting is if they got it stock and it ran rich.

 

Well after you guys help, he did get it rejetted.and after i get my yoshi stuff imma get it jetted to. THanks for your help.