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Moderator can you make this is sticky Jetting
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Posted by: hardkoratvmxr

For a 300ex with an hmf slip on and k&n or other type aftermarket airfilter go with

128 main
move needle one clip down

Posted by: hardkoratvmxr

ttt

Posted by: Sprks450r04

sound about damn good to me

Posted by: Forcefed

Good man ... been looking through the web for this info ....

Could anyone advise as to what the approximate jetting range is for the above listed mods, but with OUT the lid ? And with the addition of a high flow header ?

Thanks

Posted by: bwamos

132 main. 42 Pilot. Needle clip down 1 slot (needle up). 2.5 turns out. Fine tune from there.

Posted by: Forcefed

wow ... that was quick ! Thanks ! ... should have maentioned I was at 800'.

First 300 i`ve wrenched on. Bike came in smoking BADLY!

125 main - stock pilot - needle in 2nd clip from top !
No lid K&N - Full exhaust.....

Ring end gap was 3 times spec !

Exhaust valves burnt and guides leaking oil. Piston pin shows signs of a lot of heat!

Installed a stock bore & Comp Ratio Wiseco in the stockers place & cleaned up the valve seats.....new guides.... springs were in check....

Why is there such a large offset from the carb manifold to the head ?

And is it common for the alignment marks on the stock cam gear to be slightly retarded ? The two horizontal lines that should be on the same plane as the head are a degree or three counterclowise. Very VERY small amounts of wear on the teeth of the gear .... could this cause it - along with a worn/stretched timing chain ? Or is this a common instance ?

Posted by: bwamos

Chain stretch. If it's almost a full tooth off.. they probably timed it with the slack on the exhaust side, instead of the tensioner side. All slack should be on the tensioner side.

I wouldn't worry about a small amount.. I've never seen it line up absolutly perfect, even on a brand new engine.

quote:
Why is there such a large offset from the carb manifold to the head ?

Not quite sure what you're trying to illustrate here. It's pretty well centered across the piston and only about an 1-1/2" to the carb.

Posted by: Forcefed

The I.D. of the face of the intake port and the I.d. of the manifold where it bolts to the head has about an 1/8 off-set disrupting the flow as it transitions from the manifold to the intake port.... easily port matched with a carbide .....but it seems like honda would have lined/matched them up better than that ?

Posted by: 2muchquad

Well honda went for the fastest and cheapest way when they cast the heads.Thats why there is always casting flaws and such in the head.Due to poor quality control from the oem's thats why 2 different machines of the same model can run different from one another,go figure...