I just got a new Dg pipe for my 300ex, i'm not sure of the stock jet size, but i need a new one that's bigger. so if you have any sizes that work with a new pipe, or the original stock size, please tell me.

 

dirtpr0,
If no one replies with the correct info on your present main jet, just call the nearest Yamaha parts dept & ask them--you'll no doubt have to go there anyway to get the fatter jet. To save yourself some trouble, take the present jet out & see what type it is.. a hex head or a round head with a screwdriver slot. Yamaha has a habit of switching styles even in the same year of bike. While you're on the phone with them find out if they have the next fatter main in stock. Your needle jet should not need changing.
If you need any further info e-mail me. Re-jetting isn't really rocket science tho some would have you believe it is & I like to disprove that theory.

THE AZ HARDPACKER,

calmiller@kachina.net




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[This message has been edited by hot_shoe_cv (edited 10-04-1999).]

 

Hot_Shoe.....

Not to be a Smarta** or anything.. But when did people start calling Yamaha for questions on the 300ex ??? I am going to need to re-jet my 300ex soon too, so thanks for the help.. I hope it is not to hard.. How do you kow how high to go. i plan on getting a pipe and a K&N air filter. How high do i go. Two higher ??

Thanks
Jason



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Exer_95....Jason....95' Honda 300ex

 

dirtpro, maybe you need a fatter jet, maybe you don't. OEM jets sometimes are a little on the rich side of optimum; a new exhaust could put you right on the money.

My suggestion; if you're serious about tuning your 300ex, read your plug.

Tree Farmer

 

dirtpto. Opinions, opinions, with out them there wouldn't be a forum. The Yamaha bit was a Freudian slip i guess. So many posts on this topic are from blaster owners.
Any way witha pipe & a filter upgrade, I would go two fatter and ride & test. If it's blubbering on top end , it's too rich..drop one size. I'd rather err on the side of rich than lean. jets are only $4 or $5...way cheaper than new valves. Besides, even if two sizes fatter is slightly rich, you have that jet when you upgrade your air box.
As to plug readings on 4 srrokes, the advice I've had as well as my own experience, says that it is not really accurate unless there is an extremely drastic mixture problem. (Istill do it myself, However.;-)

THE AZ HARD PACKER,
CALMILLER@KACHINA.NET

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[This message has been edited by hot_shoe_cv (edited 10-06-1999).]