Walk Me Through Fine Tuning My set up
Do you have a 650 double pumper or a 600 vacuum secondary? I'm pretty sure there is not a 600 double pumper.
This is a 600 vacuum secondary:
The thing with the black cover on it near the rear of the carb is the vacuum secondary actuation. There are replaceable springs for it to tune WOT opening, where the metering block takes care of the mixture. Mine has the quick-change cover on it, which is surely worth it if you have one of these carbs.
If you have the double pumper, you will have idle screws back there along with jets that you can tune the mixture with. you may also have a power valve.
My suggestion is to read your plugs. If they are lightly golden brown and have no spotting on them, you're pretty good. As a side note, what is your idle vacuum reading? If its above 13 in Hg, you're probably good with the stock 6.5 PV as well.
Do you have a 650 double pumper or a 600 vacuum secondary? I'm pretty sure there is not a 600 double pumper.
This is a 600 vacuum secondary:
The thing with the black cover on it near the rear of the carb is the vacuum secondary actuation. There are replaceable springs for it to tune WOT opening, where the metering block takes care of the mixture. Mine has the quick-change cover on it, which is surely worth it if you have one of these carbs.
If you have the double pumper, you will have idle screws back there along with jets that you can tune the mixture with. you may also have a power valve.
My suggestion is to read your plugs. If they are lightly golden brown and have no spotting on them, you're pretty good. As a side note, what is your idle vacuum reading? If its above 13 in Hg, you're probably good with the stock 6.5 PV as well.