Mystery problem with my '04, Help!

[oldguy]

My '04 has 19,000 miles, a full Mark's exhaust and Morley jet kit installed 2 years ago. For the last several months the bike has refused to idle and has a serious miss/hiccup between 3000 and 3500. It runs fine at full throttle, but around town hesistates and stumbles under 4000.
We removed the carbs and they were professionally cleaned out, inspected and reinstalled. At that time we also discovered two of the carb diaphrams were wrinkly and not seating well, so we installed four new oem diaphram/slides. Tuesday, I had the carbs synched at a shop using vacum gauges . I picked the bike up Tuesday afternoon and it ran perfect. Two days later, I started it and it began to run as I described above. This got progressively worse and now it's hard starting and nearly impossible to keep it idling under 2800.
The plugs are new and plug wires are good on both ends.
Any advice is greatly appreciated.
Thanks.
Jack.

 

[m-cman]

Sounds like the fuel filter may need to be replaced and / or the fuel tank cleaned. Junk is getting back in the carbs. When that happened to me it was the low speed circuits in the carbs were plugged.

 

[tugla]

for sure the idle circuity sounds clogged up......as mentioned checking fuel system and tank. might have to get back into them and clean them out again, not sure maybe the peasooter and or shot gun might help.

 

[dannymax]

If it ran well after the cleaning then started messing up shortly afterward it's almost certainly more dirt getting back in. Talk to the guys who did the cleaning and see if they found rust particles or other crud in the float bowls (and if they changed the filter)....might give you an idea what you're dealing with.

How do you like your 'Feej'? Quite a bike, aren't they! unk:

 

[naughtyG]

On an '04 it's a bit unlikely but I would still check inside the tank with a flaslight - you just never know. If you see ANY rust, tank needs treating or replacing.

 

[jfeagins]

Stuff don't have to get in around/through the fuel filter - it can also get in past the air filter. Check your filter condition, and it's seal also. That seal can get old, rot and get into the carbs to foul things as well. Had that happen on my 86 Venture.

 

[oldguy]

The air filter is the one you get with the Morley jet kit, has very few miles and seems to be in pristene condition. I am going to investigate the business of crud in the tank and or a clogged fuel filter.
I appreciate the responses and please keep them coming. This thing has taken on a life of its own and has several pretty sharp bike guys scratching their heads.

 

[oldguy]

Does this sound like it could be an ECU issue?

 

[jfeagins]

Most likely NOT a TCI unit issue. If you aren't getting dirt back in through the air filter, it is definitely entering through the fuel system. If a good SHOTGUN proceedure won't clear the idle circuits, the carbs will have to come back off.

Before that, be certain the airbox is seated properly on all four carbs. Might check the condition of all the rubbers under the carbs and/or between the V-boost butterflies too. Air leaks can cause a lot of grief as well as the dirt.