|Posted on Thursday, June 22, 2017 - 11:07 am: ||
Recently I fouled my rear spark plug, was running rich, so I decided it was time for a carb rebuild.
I pulled the carb and extreme cleaned everything with a toothbrush and carb cleaner.
Cleaned out all the passageways with carb cleaner and cleared them with air duster.
Nothing seemed to be plugged.
Replaced all the gaskets and float needle.
Replaced the 45 pilot jet with a 44 and the 200 main jet with a 185.
Put the idle mixture screw at 1 full turn out from seated.
Went to start her up, and she wont idle.
I can keep it running by working the throttle and the enrichener.
Spark plugs indicate I am running rich, which I guess is because of working the enrichener and throttle.
I've spent hours over the last 2 weeks swapping out main/pilot jets between combinations of 220, 200, and 185, and 48, 45, and 44.
In addition to adjusting the idle mixture screw between all ranges.
Seems to run best with the 44 an 185 jets.
By all means, I can not get it to idle.
It was running great before, just a little rich, hence the fouled plug.
All of the gaskets look good, brand new, and the slide diaphragm doesn't have any tears, cracks, or holes.
The enrichener isn't sticking.
I am at wits end with this carb and I'm trying to avoid spending 300 to have a shop tune it.
|Posted on Thursday, June 22, 2017 - 01:17 pm: ||
You have replaced the float needle - is the needle seat OK? Does fuel stop flowing when the float is raised? Is the float height correct? And might do to check and see if the float has started absorbing fuel and has become 'heavy' and started to sink.
If the float and associated bits are as they should be, try turning the bike over while spraying gas into the carb mouth from a spray bottle. If it will start, and you can keep it running (poorly, I know) that way, then something in the idle/low speed circuit is blocked.
Might do to start over from the beginning, including going back to the original jets. If it worked well before with them, the problem is somewhere else.
Hope this helps, Dave
|Posted on Friday, June 23, 2017 - 08:35 pm: ||
What spark plugs are you running? OEM shipped with plugs that were not the best heat range. It's recommended to run with 10R12 plugs. Suggested starting point for carb tuning is 45 and 200, idle screw 3 1/2 turns from bottom (or was that 2 1/2). It sounds like you were probably at the recommended settings to begin with. So I have to wonder what plugs you had that fouled?
|Posted on Saturday, June 24, 2017 - 08:15 am: ||
Agreed with previous comments. 1 rear plug fouling doesn't sound like a carb issue at all but more of a spark issue (or other rear cylinder issue)
Watch that air mixture needle screw o ring, washer and spring... The o ring has a tendency to run off or get pinched ... causing all sorts of mayhem.
|Posted on Sunday, August 06, 2017 - 10:14 am: ||
So I had the mixture screw spring and o-ring in the wrong order.
I had it in screw, o-ring, spring.
I put it in the right order and got her to idle but only by adjusting the throttle position screw so that the butterfly valve was slightly cracked open.
Got me all the way to the Black hills for the Sturgis rally but it flooded when I was up in Lead.
From my understanding the bike should idle on the pilot jet circuit alone.
I've been working on it in my free time, swapping out the pilot jet and adjusting the idle mixture screw but I still can't get it to idle.
Any advice helps.
|Posted on Tuesday, August 08, 2017 - 02:17 pm: ||
The idle jet is rarely the problem on an almost stock Buell. The CV carb is notorious for getting gummed up if you let it sit with fuel for more than a few weeks. Sometimes carb cleaner in the fuel will help with a good 20-30 mile ride but usually a full disassembly is required. If this is a new problem that happened on a good running bike that suddenly had a problem. It could be the intake seals leaking. Very common problem. Sometimes a simple snugging of the intake bolts can fix it or a complete replacement of the seals