Brass plug in top of metering block?

[markmark]

Hello gang. I have a Brawler 650 with vacuum secondaries. While pulling the metering block off, I noticed this. Should I be concerned?

[Gaz64]

Spray some carb cleaner over it, then knock it back square like the other side should be. Gary

[markmark]

Thank you Gary. It was late last night and I assembled the carb. My reason for pulling the block off was to check my power valve. I wasn’t sure if the QFT carbs had the anti-backfire protection or not. Last week I drove the truck home with #7 not firing, and she was backfiring the whole way home. I have a quick question if I may. My Brawler 650 vacuum secondaries has the factory installed #65 power valve in it. At idle, in gear, my engine is pulling 9 inHg of vacuum. In park, it has 14 inHg. Is it my understanding that it'd be best to install a #45 in it’s place. My truck is somewhat of a daily driver. Thank you again for all of your help. Markmark

[Gaz64]

Leave the 6.5 in there. If you have a good steady 9 at idle, the PV will be closed. Going to a 45 may create a fuel delivery "hole" with a lean spot at part load. If you have no driveability concerns at the moment, leave the 6.5 in there. It's a good compromise opening point. That rule of half vacuum at idle is "old school" thinking. Gary

[markmark]

Thank you Gary. I think I'm starting to wear this carb out by adjusting on it. �� Once I get the truck running well, it doesn’t seem to stay that way. Fine adjustments were never my strong point. The old school guys that I’d get tech info from are all gone now. It’s cool that this forum is around. Thanks again.