jetting question

[StreetLimitz89]

okay, ive gotten my bike running from the issue i had in my last topic. since then ive not really been satisfied with the power the bike had. i have decided to get the engine bored 1.0mm over bore. i have been told. jet it or bad things will happen. i am in north carolina 1182 feet above sea level not sure on the exhaust side. i was told a fmf power core. idk if it is or isint. and a fmf gold series. Neither muffler or pipe have markings on them. muffler does NOT look stock. ill post pictures when i get a chance

 

[2strokerfun]

Don't know about the add ons, but going 1mm bigger on the bore sometimes means rejetting, sometimes doesn't. But you normally start with the jetting you have and rejet from there. In other words, don't just take a wild guess on new jets (or stick in new jets an "expert friend" recommends) before you start it up with the jets already in the carb.

 

[StreetLimitz89]

good thought, i never thought of that. but incase of needing a bigger jet kit for it where would i fine one, ebay dosent have, rockymoutianatvmc dosent have motosport either. ive ran out of places to look any ideas?

 

[Rich Rohrich]

http://www.jdjetting.com/

 

[wake_rider]

You don't need any type of kit, you just need to find out the stock sizes on the jets for that bike and buy a few sizes up and down from stock. They're good to have around...

Almost any jet will be available at a local bike shop. Get your manual out and find the stock sized jets on that carb, then call a shop and have them set aside a few jets in steps up and down from stock on your main and pilot jets. You should be set for jet tinkering, and it's exactly that: Tinkering... You will not be able to have anyone correctly tell you the setup of jets for your bike, it's trial and error.

 

[StreetLimitz89]

Exactly that. i hate trial and error.lmao that trial takes to long. and the error just frustrates me LMAO :bang:

 

[wake_rider]

Yeah, but it's easy trial and error!

Really, a factory service manual will be a huge help, but an online jetting guide will help greatly as well with being able to identify and understand what your bike is telling you and how to adjust accordingly. After about two to three jetting escapades, you'll have the hang of it.

 

[whenfoxforks-ruled]

Get a shop manual, and call JD jetting. Tell them what you have, ask them to hook you up with some spread for all year riding. He is your best bet on oem jet prices, unless you know a parts person. Keep your engine in shape, or forget about jetting. If jetting does not make sense, or does not respond properly with in 3 jet sizes, the problem is somewhere else. Get some BRES plugs, they are cheap, put the correct plug in when done. Vintage Bob

 

[StreetLimitz89]

well i contacted FMF about the jetting question and one of their tech advisors replied back with these numbers

Main- 172

Pilot- 58

Needle- R1468N

Needle position- 3rd

Air screw-1.5

and he said that would be a perfect if not Damn near close year round setup

 

[whenfoxforks-ruled]

This is not how "jetting" is. But, stranger things have happened, good luck!