29 smoothbores

any recommendations on jets? Or the notches to set it at? I have vance and hines exhaust with a baffle, dyna ignition, and k and n pods.

chelms27 wrote:

Ok, I talked to the guy and he now is saying he thinks they are 28's with the centers milled/honed/ground? out to 29 MM. What is the difference between the 26/28 visually? The carbs look just like my 26's that I know work so I am trying to decide which carbs to use. These carbs where given to me so I have nothing to lose really.

pick the 26s up in one hand and 29s in the other,youll feel the diferance!:laugh:

i would stay away from bored carbs.

not me i have 2 sets and they perform quite well better yet they were origanally two-stroke carbs [snowmobile] 36mm that are bored out to 37.5mm and like i said they work great. lot's of epoxy in them of course to block off extra air bleeds. as far as jetting is concerned try 115 or 117 mains 17.5 or 20 pilots and start in the middle position on the needle.

Some carb bodies can be bored and some just can't. Take the VM28SC from a Z1/Z1A/Z1B. It is 28.7mm ID and when bored goes about 1mm bigger venturi size. Problem is the VM series carbs all have different depths where the slides fit in the bottom of the venturi. If you bore out a VM26, it works fine... if you bore out the VM28SC I mentioned, the slide doesn't fit down into the slot and sits up about 1mm higher. When the slide sits higher, more air is getting through and it idles high... you can't get it to idle below 2.5K. If you mess around with the slides and make some mods to the slide actuator mechanisms you can get it to idle a bit lower but not much under 2K. The VM28SC assembly is ruined. If you bore a VM26 1mm, the slide will set where it is supposed to and it will idle right.

I have tested a number of bored carbs and not sure I can tell any difference. 1 to 1.5mm diameter increase doesn't do a lot except perhaps to change where horsepower is made in the powerband upwards a tad...

What do you mean I will feel the difference? 29's heavier? Also why stay away from bored carbs? Thanks for the recommendations on jets.