Do I Need to ReJet??

[02blzrx]

I just made a TRX450R silencer fit onto my 350x, Do I need to rejet? If so what size jet would I need and Where could I get one?
Is there a tutorial on these things? I am not sure I understand their purpose that well.

My Bike is stock, -Uni Filter and now the Silencer/Exhaust so I imagine it has the stock jet. Also it gets terrrible gas mileage. So I think Maybe I need a new jet?

[BIGCRIP28]

Maybe, do plug checks to find out.
It is going to get bad gas mileage because big engines burn alot of gas.

[yamatopdog]

I just made a TRX450R silencer fit onto my 350x, Do I need to rejet? If so what size jet would I need and Where could I get one?
Is there a tutorial on these things? I am not sure I understand their purpose that well.

My Bike is stock, -Uni Filter and now the Silencer/Exhaust so I imagine it has the stock jet. Also it gets terrrible gas mileage. So I think Maybe I need a new jet?

I dont know where you can get one, but i do have a basic understanding of the purpose of re-jetting. When you modify the intake/outflow of an engine, you are either making the engine push fuel/O2 in or out more quickly or more slowly. Depending on which it is necessary to re-jet. The purpose of going UP in a jet size is to let MORE fuel into the engine because your NEW exhaust is pushing out the mixture MORE QUICKLY this is essential as to not allow detonation. Detonation occurs when NOT ENOUGH fuel is entering the combustion phase simply because your new exhaust is exiting the fuel/air more quickly. Fuel entering and entering the combustion chamber at the right amount is essential to cooling the engine properly. Two things you can do is check " piston wash" and "spark plugs" I like to have an almond colored spark plug on my snowmobiles. Some people like them darker to be on the safe side. As for piston wash, do a google on that as there are some good explanations all over the net. The bottom line is, you need to keep that engine cool.... I dont own a three wheeler, but i know from owning yamaha snowmobiles that if you cannot get your hands on a larger jet, you can always adjust the needle in the carburetor. There should be 5 settings on the needle with the clip.

Jared

[02blzrx]

I do appreciate your post. very informative. Thank you.

Does anyone have Pictures of the Jet. nit sure which thing it is on my X, in my case I would nedd to back off probably, right? Or am I off?