petcock causing motor to run rich?
 

Ok so i have been chasing a rich running motor issue for a while its not by any means horrible riding but you can defenitly tell after cruising highway speeds in 6 gear that the performance starts to dwindle until you rev the motor a few times to burn off the extra fuel. it seems like it is running rich but I have Cleaned, and synced the carbs multiple times, looked at the jet sizes like 30 times.... stock. Plugs look perfect when i pull them each time

But after reading a post about gast tanks i see that the petcock on my tank does not have the vacuum line hookup on the back of it. Infact the petcock is not the stock F2 valve.

Could a petcock flowing to much gas cause a motor to run rich?

RE: petcock causing motor to run rich?
 

also the vacuum line from cylinder 1 has the hose attached but a screw is in the end of the hose blocking it off.

RE: petcock causing motor to run rich?
 

Sounds familiar. I had a similar problem that was remedied by syncing the carbs and adjusting the air bleed screws correctly. I have a 92 f2 that I resurrected from the grave. The fuel system was clogged from sitting for over 5 years. I cleaned/rebuilt the carbs, had the tank refinished on the inside andfactory petcock was hosed so I replaced it with a Pingle dual outlet model (~$125 instead of factory ~$250). I do have a unifilter and a full D&D exhaust though. That could be balancing the extra fuel flow. The float bowls should be adjusting the fuel correctly.

I have all the vacuum ports blocked with vacuum caps. I do not have a line to the petcock.

RE: petcock causing motor to run rich?
 

It's probably not the petcockor the plugged vaccuum line. Mine is set up the exact same way and it is running perfectly. A rich mixture is the result of incorrect fuel metering. You may have to seek proffessional help if all else has failed.

RE: petcock causing motor to run rich?
 

hey guy, when was the last time the carbs were cleaned,i'm 80% sure if you haven't had the float needles changed they will stick the same way a toilet would if the plunger doesn't drop, the gas will flow constantly,that would cause the fuel to flowcontinously over load the carb or carbs and cause it to run this way and may foul the plug or plug. the best way to chase this problem is to check the plugs to see which one has the most gas in the cylinder .that is theneedle you change.i'm a certified motorcycle mechanic for over ten year,this was a common problem for f2-f3.lmk how you make out. good luck!!!!!!!!!!!!!!!!!!!!!!!!

RE: petcock causing motor to run rich?
 

I am kind of having the same problem, i just got my bike running from a completel rebuild this past winter. i will get on the parkway and i will try to hold it at 6 grand, around 75 to 80 mpg, sometimes the bike feels like it is trying to cut out for bog down a little but when i give it more throttle, it takes off, it seems to bog when i try to hold a steady speed in 6 gear, and i think sometimes in 5th. i was wondering if there was any quick fix like carb cleaner in tank or sea foam. i already had the bike tore down and i'm not looking at taking the carbs back off.

RE: petcock causing motor to run rich?
 

and my bike does not have a jet kit, i do not like jet kits, i believe in stock bikes unless i'm planning on racing

RE: petcock causing motor to run rich?
 

And that was my thinking as well, but i have cleaned the carbs 4 times in the past 3 months. I am this weekend going to a buddies who can "professionaly" tune the carbs and setup the suspension for me.

Hopefully this will fix the problem. cause who needs a brand new bike when you got a screamin f2? :)

RE: petcock causing motor to run rich?
 

just remember to have him check your float needles. good luck lmk how you make out.

RE: petcock causing motor to run rich?
 

ok so we hookeup the carb sync meter and lone behold.... they all were spot on. perfect sync. so now my guess is going to the float needles. my question is that there seems to be a lot of play between the needles and the floats. now the needles looked good and seemed to operate correctly............ well at least i found out what isnt causing this...... again :)


well just to add to my frustration last night I was out riding and the damn RR went out, & burned up the battery. in a turn at about 11 pm and my headlight starts to flash on and off then, then no power bike sputters and dies

..... so i do my best to keep my line in the corner and managed to keep the bike up. made it out ok, and that was the scariest thing i have been through on this bike.