Topic: Jetting

[mrbreeze]

Well......After more attempts than I would like to list right now, I finally have the combination!!!! I am back to my 137.5 mains but this is the first time I had them on with the needle in the 4th notch. Man this sucker is runnin now (and I haven't even synched it for the last two adjustments!)I guess I'm runnin a slightly fat main now but it just recently occured to me that my needle must be too fat.This bike has never in 5 years ran this good!!! I'm jazzed.... It's fun to ride again(now that its gettin in to the fall...Oh well...this spring will be good)

[paulages]

what's yer bike?

[mrbreeze]

750 K5.4to1,pods,dyna ignition.

[paulages]

what were your stock mains for that model?

[eldar]

Stock mains were usually 120s I think.

[dusterdude]

oh jeez.we have a k8 guy thinking.

[eldar]

Well them K8s require so little work and are so reliable that we usually do not have to think. But that is what happens when you have so few problems!

[mrbreeze]

My model came with 105's stock.The early 750's had 120's. Since I went 4 to 1 exhaust,pod filters, and Dyna ignition,I have worked with different combinations of 120,125,and 137.5 main jets And the middle 3 notches on the needles. "DUDES!!!!"........I am there finally and it feels good.Plan to synch this weekend and buy wings......take a flight!!!Will report back. PS....Hey Bob...Can I join the carburetor club now?

[eldar]

You have an F model then huh. Those did have different mains than the Ks did.

[mrbreeze]

No Eldar.It's A K model.

[dusterdude]

yea eldar,the man said it was a k.

[Terry in Australia]

Hey Eldy, according to the factory manual, your K8 should be running #110 mains. Cheers, Terry.

[murtceps1]

MrBreeze what problems did you have before. I am the owner ( not master) of a cb750k that is driving me nuts. I also run pod air cleaners I have been advised to decrease the size of my main jet but you have had success going the other way. Or did you compesate by altering the needle hight. My manual says main std jet 120.
My plugs are sooty 

[eldar]

I think mine does have 110s and the F models are the only ones I know of that came with 105s now I suppose they could have been changed before and so it could be a K or it could be a K with F style carbs.

[mrbreeze]

I ran the 137.5 at the mid clip on the needle and it was okay at the top end but spotty in the middle.I moved the clip down to the 4th notch(which raises needle-- richer). Now it was noticably runnin rich so I tried going back to 120 mains.There,it was doing okay on the highway but lousy around town. Took carbs back off and moved clips to 2nd from top position(lowered needles--leaner).Now its great in the midrange but when you give er the onion,it bogs.From there ,went to 125 mains....better but still not on.Then I thought....I have already ran the 137.5's at mid clip and 4th notch... now that I'm at 2nd notch,lets try the 137.5's again. Bingo! Thats where mine runs best