Valkyrie running rough

[Valk55]

My 2001 Valkrie standard is running rough and wondered if anyone has any ideas. For some background info, it was running fine earlier in the summer, but sat for approx a month and a half without being run. When I rode it after that, it started running rough like it was missing. I checked the plugs and the left side rear plug (number 6 I think) was carboned up. All the rest of the plugs looked fine. I cleaned that plug and filled the tank with fresh 93 octane fuel and added some sea foam. It ran ok for about 50 miles and then started running rough again. I checked the plugs again and the same one was carboned up again. Has anyone else experienced this? Any advice on what the problem might be? Thanks!

[Chrisj CMA]

You stated the problem.  Leaving it set for so long.  The carbs need cleaning out.  Maybe, (just maybe) some better additives like techron in stronger concentration may do it.  If not its a carb tear down and clean or replace jets.

Also check all the vacuum lines.  If they have never been changed they are most certainly cracked.  There should be one from intake #6 going to the petcock....it that one is cracked it could maybe cause what you describe because it will affect the operation of the petcock

[hubcapsc]

When my buddy's #6 plug was fouled, it turned out to be his petcock... the diaphragm
was messed up, and the previous owner had noticed a leak, so he plugged the
petcock weep hole. Then the leaky gas flowed down the vacuum line to #6 and made
a mess of that cylinder. Probably a recipe for disaster too, maybe luck he didn't
hydrolock...

-Mike

[Bone]

My 98 did that last year. I could pull the spark plug from #6 it would be sooty. Clean it and ride 50 miles and it would be fouled. Mine had a tear in the petcock diaphragm that let the gas run down that vacuum line.

[Ricky-D]

You read it here on the forum

Diaphragm !!!

Get the  repair kit.     

Someone will post the part number.

***

[Valk55]

That makes sense. I was wondering if it was a carb plugged up why it would only show up on one cylinder. I went for a short ride this afternoon and I noticed a drip from the petcock weep hole. When I checked these responses you all were telling me to look for what I had just seen. I will get a petcock rebuild kit ordered. Thank you all so much for your help. 

[custom1]

Definitely sounds like you found the problem. There are actually 2 diaphragms in there that need to be defective for fuel to get to the vacuum line. Here is a diagram I have saved from this site. Disregard the bottom diagram.

[John U.]

Check the microfische on HDLparts.com. You need what's called a "cover set". It does not include a new screen, you have to order that seperately.

[Jess from VA]

http://www.hondadirectlineofshadyside.com/stores/product.asp?pid=44481&str=2&ID=538187533

[Valk55]

Update: Re-built the petcock last Saturday and problem solved! It runs great again. I think in addition to it leaking fuel into the vacuum line causing the #6 plug to foul, it was also causing a vacuum leak. Thanks again to everyone for the advice!