RE: walbro wt 813 carby on 5b ss
I got an 813 on my fg with a reed ported 28.5....no problem at all...idles great and was a cinch to set up...even starts below zero after 6 or7 pulls. getting one for my race ported 28.5 rampage next. Essentially the only difference between an 813 and 668 is accelerator pump and no choke, should idle fine.
There's all sorts of talk about these carbs being hard to set up and for boats etc...for tuned engines they totally eliminate the low end bog off idle, they flow more wot cos there is no choke to upset the airflow, they are popular with boaters because boats are nearly always tuned and to get out the water quick they want to eliminate that low end bog, the carb is not strictly just for boats however. I think a lot of the negative hearsay is posted by folks who have never run one...I'm sure you'll get a few posts here both for and against the 813 but my own experience with one I think it's a great carb for my application.