I'm familiar with the GMS 47 fix(es) & set-up, having had one of those nasty brutes, & I still own a Tower 46. The behaviour of the GMS 76 is not quite the same -- it doesn't flame out -- it just seem to come & go of its own volition & is quite unresponsive. I have indeed been through the works -- back & forth with high & low needle settings to no avail -- until I drilled the spray bar -- which seem to work (on the ground). BTW, the low speed setting on the 76 is dead easy -- not at all fussy like the 47.

I haven't checked the big-end for play, but I guess that is next. The con-rod shouldn't be failing after 4 gal of fuel.

My 76 has the finned (low performance) muffler & it still has the baffle in it. I have been reluctant to unbaffle it because of the erratic operation -- I had memories of GMS 47's dancing in my head.

I also have a Tower 75, which has none of these problems & has a bucket-full of power to boot. It has a "tuned" muffler -- I'll give that a try on the GMS 76.

Thanks