VM28SS question

I'm just curious about something I noticed about the VM28SS carbs on my bike.

If I remember correctly, all the other carbs I've worked on in the past have had o-rings on the air screws (or pilot screws) but, these don't. Just the screw and a spring.

I seem to recall something I read about these carbs in a manual or somewhere else that, after the adjustment was made, the plugs should be re-inserted and sealed over the screw.

Is this a requirement? Would this be a possible air leak point if left uncovered?

Just curious as they were uncovered when I purchased the bike...

Sonny

Side-located pilot air screw has no o-ring and won't leak without the plug (an EPA feature to discourage adjusting).

But would maintain ever vigilant lookout for the EPA plug inspection police to avoid arrest and firing squad.

Good Luck!

If you suspect an air leak, you can always remove and read the sparkplugs to get a good sense of the air/fuel ratio you are running in each of the cyls. and make the necessary minor adjustments on the pilot screw to dial-in the perfect color for each plug. Good luck. It's probably a non-issue, but read your plugs anyway, it's fun..good luck.

The pilot screws are air screws and adjust the amount of air going to the pilot circuit at idle. Any adjustments will only affect plug burn/color if you only idle the bike. If you ride it on the street, the mid-range jet needle/needle jet combo and main jet have far more effect on the plug burn.

wiredgeorge wrote:

The pilot screws are air screws and adjust the amount of air going to the pilot circuit at idle. Any adjustments will only affect plug burn/color if you only idle the bike. If you ride it on the street, the mid-range jet needle/needle jet combo and main jet have far more effect on the plug burn.

YEAH!,...what he said! :laugh:

Anyway, I suspected they were OK to leave open, I just had the thought of that passage I read haunting me and needed y'all to reassure me.

BTW, got the bike all back together now and my throttle hang is cured!

Was probably the advancer cleaning and lube that did it.

Thanks,
Sonny