Walbro Carburetor Swap

[Four Paws]

I need some help. I finished modding my 695 Shindaiwa yesterday. The gains turned out to be quite significant. It is a 68cc saw and the stock carburetor is a Walbro HDA-29 with a 16.66mm venturi. I am at 5000' ASL and when the saw was stock, I had the carb tuned at 1-1/8 turns out on both H and L. Now, I am 1-3/4 on the H and 1-1/2 on L. I am almost positive this saw would benefit from a slightly larger carb.

I am pretty sure there is no biger HDA carb available - if there is, please let me know. I believe the next larger series is WJ. Does anyone know what the bolt pattern is on a WJ? I am looking for dimensions to see whether or not it will be a direct bolt in swap.

If any of you guys can measure the center-to-center distance on your WJ carb, or if you have a WJ laying around, maybe we can work out a deal! I am looking for a carb with a 17.5mm-18.5mm venturi.

Thanks a bunch, Josh

 

[Jacob J.]

Some of the hotsaw buys may have a better answer but I'm thinking there's a few regular HD carbs that have a slightly bigger venturi and would definitely flow more fuel, like the HD from the early Stihl 046s. There was a run of them from pre-EPA saws that had the #72 metering jet. I can't remember the exact venturi size, I seem to recall between 17 and 18mm.