WGREGT Posted August 2, 2019 Share Posted August 2, 2019 Hey peoples. I’ve got an 85 VF500F that ran like a champ...until I let it sit for too long. I pulled the carb bank and cleaned them and reinstalled...more than once. New carb boots x4 as well. All carb diaphragms have been checked extensively more than once and have no holes or rips etc. It’s marginally better bc it will technically idle now, but when given gas it bogs down and cuts off. If you gradually and o-so-gently feed it gas and get it up to 4-5000 rpms and release the throttle, it takes an eternity to come back down to idle. I have not pulled the carb bank all apart and cleaned it. I’ve removed, soaked and cleaned the holes, jets, passages, pilot jet screws, etc with carb cleaner and air compressor. All more than once. My thoughts is...vacuum leak somewhere. Anyone know possible spots to look for a leak etc? Or would you....pull them all apart and reclean...or have a shop do it? I cannot imagine all of this still leads to gummed up carbs but then again all it did was sit for 4 months or so. It has gotten marginally better after all of these multiple cleanings bc it used to not even idle, though I did ride it somewhat hard (with Seafoam in the tank) for 30 miles or so right when this whole fiasco started. It idled sorta ok then as well. I’m stumped. This has been a 3 month fix so far. Link to comment Share on other sites More sharing options...
jeremyr62 Posted August 2, 2019 Share Posted August 2, 2019 Did you try the butane (any flammable) gas trick to look for vacuum leaks? Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted August 2, 2019 Member Contributer Share Posted August 2, 2019 @TheDutchy Link to comment Share on other sites More sharing options...
WGREGT Posted August 2, 2019 Author Share Posted August 2, 2019 @huh? Link to comment Share on other sites More sharing options...
WGREGT Posted August 2, 2019 Author Share Posted August 2, 2019 Just tried the starting fluid thing. Got no reaction at all. I also tried carb cleaner, because it had a straw that I could direct a little more where I wanted it to go. No reactions either. The one thing I did notice that when I had the airbox off and I manually slid the carb slides up with my fingers, two of them increased the revs when I slid them up, and two had no reaction at all. Which makes me think I need to look at the rubber on the slides again. This will be the fifth time I’ve taken those out and looked at them under a lightbulb. Link to comment Share on other sites More sharing options...
jeremyr62 Posted August 2, 2019 Share Posted August 2, 2019 When you had the airbox off and the engine running when you twist the throttle do all the slides move up? Link to comment Share on other sites More sharing options...
WGREGT Posted August 2, 2019 Author Share Posted August 2, 2019 yeah...they shake and vibrate a little at idle of course but they pull up, the bike stumbles and cuts off though Link to comment Share on other sites More sharing options...
squirrelman Posted August 2, 2019 Share Posted August 2, 2019 make sure you put a thin steel wire (,010") clear through the idle jets and side holes in emulsion tubes. Link to comment Share on other sites More sharing options...
WGREGT Posted August 2, 2019 Author Share Posted August 2, 2019 yep. All the tubes are clean. Soaked them and blew air thru them and visually checked them at least 5-6 times each tube over multiple tries at the cleaning. Link to comment Share on other sites More sharing options...
squirrelman Posted August 2, 2019 Share Posted August 2, 2019 neither air nor soaking can accomplish what a wire can for cleaning out holes. Link to comment Share on other sites More sharing options...
WGREGT Posted August 2, 2019 Author Share Posted August 2, 2019 If I can see thru all of them, they should be clear. Link to comment Share on other sites More sharing options...
squirrelman Posted August 2, 2019 Share Posted August 2, 2019 10 minutes ago, WGREGT said: If I can see thru all of them, they should be clear. not true, as a ring of hardened debris can accumulate, so you see a smaller hole than was original, and that;s why a wire is necessary to force debris out and act as a GAUGE to verify the hole is original size. Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted August 3, 2019 Member Contributer Share Posted August 3, 2019 7 hours ago, WGREGT said: @huh? That @ should have sent a notification to that member 😎 He knows VF's.... Link to comment Share on other sites More sharing options...
WGREGT Posted August 5, 2019 Author Share Posted August 5, 2019 On 8/2/2019 at 8:47 PM, Dutchy said: That @ should have sent a notification to that member 😎 He knows VF's.... Cool. Have him post up his opinion if he has one. Love to have him weigh in. Link to comment Share on other sites More sharing options...
WGREGT Posted August 18, 2019 Author Share Posted August 18, 2019 Hey anyone have a part number or possible equivalent part number for the tiny o rings on the pilot air screws? I have a definite leak on one at least. Fiche shows I need to buy an entire kit? Surely there’s a cheap and accessible substitute, right? Link to comment Share on other sites More sharing options...
Smack Posted August 18, 2019 Share Posted August 18, 2019 Measure the o-rings and just buy them from McMaster Carr or a local o-ring shop. I choose Viton when possible to resist alcohol corrosion. Link to comment Share on other sites More sharing options...
WGREGT Posted August 19, 2019 Author Share Posted August 19, 2019 Mine are so jacked, torn and flat I'm not sure I have a measurement to go by. Anyone have one handy and can tell me the specs, etc? Link to comment Share on other sites More sharing options...
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