Carb jets

[mach1charlie]

Where can I buy 37.5 idle jets @ a reasonable price ?

[Steve in Sunny Fla]

there is no 37.5, the jump goes to 38 then 40. I understand that the "new" 40's are the same flow as the old 38's. Of course the easiest way is to drill the 35's you have with a # 78 drill. But I have to ask... why? There's absolutely no nessessity for it, it will kill your fuel economy and not fix anything I haven't already fixed with the 2 minute mod jet kit. Steve

[mach1charlie]

Well Steve, I am a guy who jets by the seat of my pants. bought this bike because Im poor and got a hell of a deal on it. Bike was not running. pulled the carbs and cleaned em, and had a running bike, that was 13k and 8 months ago.

Bike just feels lean to me on the bottom, needs lots of choke and has a leaqn misfire up to 3-4k rpm.  idle circut is 2.5 turns out. 

I do have .020 shims to go under the needles and I am at least gonna run a drill thru the idle jets "next size up"

 I live@ sea level (florida) and always get good power jetting fat.  Bike is stock other wise.

Do you think I will "kill" the mpg?  I get 40/42 now.   

PS main jet feels good to me

Thanks Steve, I value your opinion.

[MAN OF BLUES]

 
sorry.
I believe you have other issues if you have lean stumble.....
before you start drilling stuff, you really ought to have a supply of parts on hand, or at least have a connection for them, in order to reverse the process when you go too far, and it sounds as if you will do just that.
Conni in all forms runs rich. I think you need to clean the low speed circuits completely to find that missing "oomph"

[Steve in Sunny Fla]

MOB is correct, the factory carburetion is fat, and lifting the needles only made it worse. I did the drilled pilots thing about 6 years ago, and promptly lost major mpg's. Also tried raising the fuel level - 2mm high = -8mpg! the problem you're dealing with may be the built in stumble connies have. Seriously, i've done 3 different jet kits on these bikes, and know how they work. You absolutely cannot beat the 2 minute mod jet kit for perfect carburetion. Steve

[WillyP]

You'll find plenty of testimonials for Steve's kit... Why go through all the trouble when Steve already has, and has done it spot on? By the time you go through all the trial and error yourself, you will have spent far more than the price of Steve's kit.

[SteveJ.]

You'll find plenty of testimonials for Steve's kit... Why go through all the trouble when Steve already has, and has done it spot on? By the time you go through all the trial and error yourself, you will have spent far more than the price of Steve's kit.

This.

 BTW, any cracks/leaks in the air induction system? Perhaps a vacuum leak? Simple, easy, cheap  stuff first.

[medicevans]

+10 for Steve's kit. I guess if you're into that kind of stuff, you could experiment until you figured it out, but seriously; you could end up spending quite a bit of money before you figured it out and still end up having to buy Steve's kit.

Also, I'll second the air leak checking. A small leak in these systems can really throw the power off. Pull your airbox or get down and really look to make sure the seam isn't coming apart.

[mach1charlie]

Well, Thanks everyone for the sound advice.  Them carbs are hard to take off... so I  want to change somthin'

Truth be told, I need to run the valves first.

[SteveJ.]

After a few years and many heat cycles, the boots between the carbbies and the airbox get really stiff. Do yerself a favor and order up a new set from Murphskits.com.

Also, when done futzing with the airbox and carbbies and such, double check on the bottom of the airbox that the crankcase breather tube is still attached.

Ain't carburetion fun?

[buzzcut]

+ on sisf jet kits.

[MAN OF BLUES]

I had a feeling this was coming..
http://www.zggtr.org/index.php?topic=1930.0

[jim snyder]

Well, Thanks everyone for the sound advice.  Them carbs are hard to take off... so I  want to change somthin'

Truth be told, I need to run the valves first.

Yes Charlie, don't drive yourself crazy messing with the carbs, when Steve has already got it figured out.
His new jet kit will be the best money you could ever spend. Trust me you will thank us later.