blown diaphram?

[mack]

Well, started the diagnostic on the fuel situation. Vacumn lines are clear, tank vent is clear, petcocks are flowing, pulled the forward lines off the petcocks, turned them on with no fuel flow, sucked on the vacumn line and only got flow out of right side. Blew on vent lines and are all clear. Removed ther octy and could blow through easily. Removed filters and could blow theough. Hooked it back up and ran bike for a bit. Right side filed filter, left side not so good. Watched the level drop. So left side seems to be weak. Blown diaphram in #1 or #2?

[11Rider]

I'm not understanding what you mean when you say "right side filed filter", but it sure is easy enough to take the tops of the carbs off while they're on the bike and check the diaphrams. About the only thing you have to do first is take the tank off. If you do have a bad one, I remember reading a post not too long ago about a way to repair them with some kind of rubber spray coating.

[g15usmc]

Well, started the diagnostic on the fuel situation. Vacumn lines are clear, tank vent is clear, petcocks are flowing, pulled the forward lines off the petcocks, turned them on with no fuel flow, sucked on the vacumn line and only got flow out of right side. Blew on vent lines and are all clear. Removed ther octy and could blow through easily. Removed filters and could blow theough. Hooked it back up and ran bike for a bit. Right side filed filter, left side not so good. Watched the level drop. So left side seems to be weak. Blown diaphram in #1 or #2?

Are you talking about inline filters? off the octy?

[motoman]

Maybe tower filters in tank a bit restricted?.........weak vacuum on octy(crack in a vacuum hose)........JAT.

[g15usmc]

Are you talking about inline filters? off the octy?

if this is the case i would try running petcock to filter to carbs and see what happens...if that works, ur problem prolly lies with the octy and not the carb...I know you said you tested the octy but what you describe is exactly what was happening with my bike before i removed the octy...and according to the testing i did the octy was work properly...but for some reason i was not getting enough fuel in those two carbs...take the octy out of the equation and bammo bike runs like a charm...except now i have to rebuild a petcock...BLAH!

[mack]

Yes

after the octy, just before the carb inlet T's. In line filters both sides. Fuel flow at petcocks unrestricted.

[g15usmc]

after the octy, just before the carb inlet T's. In line filters both sides. Fuel flow at petcocks unrestricted.

try my above comment...dont know if u saw it already is reason for this post...hope its just the octy...less to deal with that way...

[bikerphil]

+1 on getting rid of the octy. You can cap the front outlets of the petcocks and run the rear lines to the carb T's, then run the petcocks in the on or reserve position. That octy has left me stuck out in the middle of no f'n where before, I'd lose it, JMHO.

[mack]

Could be the octy

I just can't figure out why one side flows and the other doesn't. You'd think that when they crap out, no fuel would flow, or worse it would flow all the time. So when you cap off the forward petcock line. What are you using to cap it off?

[bikerphil]

So when you cap off the forward petcock line. What are you using to cap it off?

Don't use vacuum caps, the fuel will eat them up. I use a short piece of fuel line with a bolt stuck in there. Saw the threaded part of the bolt off and use the shank and the head. Another way is to stuff a ball bearing in a piece of fuel hose.

Edit: Mack, don't forget to turn your petcocks to the off position when you're done riding.

[SFerinTEXAS]

Either side petcock in the correct position and fuel hoses plumbed correctly on a SF with an OE octy will feed all the carbs. I don't use the front nipples on my SF tank valves but do use (and value) the purpose of the octy
I will suggest what you think to be a fact is not true. Question your previous conclusions.