173 blue motor, anyone built a hot one?

Thats ok.. cheers anyway, I'll start playing with the cruise timing once I get the fuel dialed in how I want it. At the moment it still has the odd fat spot and lean spike.

It'd probably be better to get the cruise timing at least in the ballpark before you make any changes to the fueling. If the timing is retarded it will give misleading a/f readings, so if you do fuel first you'd probably end up having to go back and do it again after the timing was done.

It'd probably be better to get the cruise timing at least in the ballpark before you make any changes to the fueling. If the timing is retarded it will give misleading a/f readings, so if you do fuel first you'd probably end up having to go back and do it again after the timing was done.

I swapped back to the memcal that I had done in Dec, it looks like it's more my bad tuning than the motor not being able to handle lean cruising. I took a bit of timing out of it in the high vacuum/ low RPM areas because I thought it was a bit high, thats why I asked how much the vac advance pulls the timing under light loads with a normal dizzy (looks like I went the wrong way).

I'm trying to copy as best I can the original tune as its pretty good, just idles a bit high and chews more juice that I believe it should.