2004 fuel / carb / running problems

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Corrugated

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Location
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Hello All,

Had some running problems with my 2004 a few months ago, discovered some rust in the tank and have since pulled and cleaned / sealed the tank and reinstalled. Installed new fuel filter as a further precaution. Just finished performing the Shotgun clean on all 4 carbs (seemed decently clean, could get air to pass through the passages without problem), noticed tiny spec of sediment from the RH rear carb. Went to test start and now I'm getting continued running issues as followed:

  • started up with choke, wanted to run high (over 3000 rpm) until choke almost all off
  • readjusted idle mixture screws on each carb to 2.5 turns out (washers and orings did not come out when Shotgunning, assuming they are OK and still inside carb. body..) mix screw tips were not worn or dirty, wiped them down and reinstalled assuming OK
  • can get to idle around 1000 rpm once warmed up, but..
  • wants to die / back fire through carb air inlets when given throttle (had 1 big exhaust backfire then stopped working on it to further diagnose)
  • can see fuel trickling out of the slide needle / seats at all 4 carbs (normal or not?) looking down the air inlets when running
  • rpms will increase and hold for a moment when throttle applied (choke is now off), will slowly go back down
  • exhaust smells fuel rich
  • once warmed up and adjusting idle, engine rpm will now run on high, had to cut power to ignition
  • RH rear carb had some billowing of combustion smoke coming out air / throttle valve inlet (I believe this carb initially had some sediment plugging it before the Shotgun) after engine was shut down
  • haven't resynched since Shotgunning yet (will once running properly)
  • I believe all cylinders are firing (will check exhaust pipes with a temp gun, but felt hot)
Just trying to get corrected before having to remove and service all 4 carbs. Have not opened carbs further or adjusted float levels as of now..
Any thoughts on what to try next?..

Thanks in advance!
 

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Hey how's it going? I went a bit through your pain a few months back. Just got another max last yr - an '03 and the thing had under 25K mi and apparently sat maybe. I put 'er to good use, maybe a little too much, but who's judging here? Haha. Ran it dry on a ride the day after I changed my fuel filter, then the whole acting out part like the symptoms you describe. Mine is like totally untouched so I did not mess with mixture screws, etc. Inside of my tank looked new so nothing evident upstream of fuel pump. Bowl drain #1 tube was 0 flow, others drained fine with really fine grained sediment. I read related posts here and put a few member ideas to use as last resort to pulling carbs last fall. Basically used a syringe to suck the drain tube and it pulled really hard. Then a few blobs and a little gravity dripping began. Then big mosquito bodies with repeated suction, I swear lol, more likely varnish from unstabilized fuel from PO maybe. Anyway pics show it all, works like a champ and was an immediate fix after that with no carb pull needed to pull the bowls. Maybe give that a try and see otherwise you might have dirt getting in the needle jet going on causing the flooding raw gas smell and sh^t idling/stalling/loping.

good luck
 

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Hey how's it going? I went a bit through your pain a few months back. Just got another max last yr - an '03 and the thing had under 25K mi and apparently sat maybe. I put 'er to good use, maybe a little too much, but who's judging here? Haha. Ran it dry on a ride the day after I changed my fuel filter, then the whole acting out part like the symptoms you describe. Mine is like totally untouched so I did not mess with mixture screws, etc. Inside of my tank looked new so nothing evident upstream of fuel pump. Bowl drain #1 tube was 0 flow, others drained fine with really fine grained sediment. I read related posts here and put a few member ideas to use as last resort to pulling carbs last fall. Basically used a syringe to suck the drain tube and it pulled really hard. Then a few blobs and a little gravity dripping began. Then big mosquito bodies with repeated suction, I swear lol, more likely varnish from unstabilized fuel from PO maybe. Anyway pics show it all, works like a champ and was an immediate fix after that with no carb pull needed to pull the bowls. Maybe give that a try and see otherwise you might have dirt getting in the needle jet going on causing the flooding raw gas smell and sh^t idling/stalling/loping.

good luck
Thanks for that. Luckily the bowls on mine have drained with no trouble. I went to re-Shotgun yesterday and rechecked for the idle mix screw washers and orings (first 1 come out fine, second carb I noticed they weren't even in there). I've now ordered a new set of 4. Also checked the PAJ jets and noticed the PAJ1 jets are marked '05' on them not '100' like I have read they should be (unsure if the previous owner had changed any carbs parts from when he had owned it). Ordered a new set of them to be sure as well. PAJ2 jets were marked '170', so good to go there. Will continue the operation next week...
 
Hey it's great you've discovered some anomalies with seals and jets, always hard to say what PO's changed or lost, and great points to tackle in your troubleshooting.

To add more info to my post, #1 was absolutely clogged, and although the other 3 bowls drained on their own, only the syringe would pull the larger globs out. I gravity drained and refilled #'s 2-4 twice with no fix to the problem, and it was only after I used the syringe that would pull out those adult mosquitoes. Basically it appears the large blobs tend to settle in the bowls somewhere and move all around unless you vacuum action them out or remove carbs and then bowls. There is no way the size of those globs would fit through the tiny plastic elbow fittings and tubes on their own. I did all carbs 4 times refilling in between, and drained over 1/2 litre out total, and pulled the absolute largest crud out of both #'s 1 & 2, and pulled some way smaller sized globs in 3&4 that would not simply gravity drain out.. I knew dirt was the problem here because the carbs and most other things on the bike were never visibly removed based on the fasteners and original assembly, and the problem happened all of a sudden - like bike seeing vboost usage alot for a change, new gas circulating, then accidentally running out of fuel which likely dislodged the globs free that now interfered with floats and jets is my best guess..

All the best in your fixing!
V
 
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