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Quote from: 86FJNJ on Yesterday at 01:42:39 PMIf you can't get it dialed in as is it would be worth trying the other slides and tubes. Are you sure the grey exhaust was from too much fuel? My FJ smokes like a chimney after the fist 30 seconds for about 3 minutes because the valve seals are original and oil leaks past them when sitting so when I first start it that needs to burn off. After that it doesn't really smoke.When we went to 2.5 turns out, after it had warmed up for 10 minutes, it started emitting the smoke again out the pipe hence why we were concerned it was too rich at that point More specifically, when blipped. Turned it down to 2.25 and the smoke cleared even when blipping.
If your FJ was running well at 2.5 out but just had some smoke I'd be tempted to ride it like that and then keep tuning from there after you know how it's behaving more after warmed up and through the rpm range. It's going to be tough IMP to dial in the carbs without riding it. Is this a bike you had running well at one point in the past or is this something you got from PO and have been rehabbing it but not ridden it yet?
Quote from: 86FJNJ on Yesterday at 12:39:36 PMIn my early FJ days I went with some cheap china ebay stuff for carbs and learned my lesson too. Have you tried 2.5 turns out on the fuel mixture screws to see if that improves things?The jets are all original Genuine Mikuni parts, all have the maker mark on them. The 42.5 jets I had put in were from RPM. I currently have the flat bottom slides and y-0 Emulsion tubes in the carbs. But I also have a set of round bottom slides and y-2 emulsion tubes that came from an 85 FJ100. Should I switch it over to the Y-2 tubes and round bottom slides?
Here in NJ it will be 50F tomorrow, if you have any warmer days in your area a test ride would be good if the bike responds/runs well in mid range and top end then it's likely a fuel issue in the pilot circuit either related to your fuel mixture screws, non-OEM pilot jets and/or clogged passageways in carbs.
I had a set of carbs I could not get fully clean, I put seafoam in the next few tank fill ups and went out for several spirited ride and that helped. Since then I run Yamalube Ring Free Plus Fuel Additive in each tankful of gas to help keep things clean.
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Quote from: 86FJNJ on Yesterday at 11:48:20 AMhow many turns out are your fuel mixture screws?About 2.25 turns out. I'm not sure these mixture screws are OEM, they seem longer. They were obtained before I learned my lesson and started getting my supplies from RPM.
Quote from: T Legg on February 26, 2026, 01:45:37 PMIt could be a bad diode in the diode block #27 on the factory manual schematic.The kickstand relay contacts when closed ground out the ignition control and prevents the spark plugs from firing. When the kickstand is up it closes the switch and gives the kickstand relay coil a path to ground energizing the coil and causing the relay contacts to open up ungrounding the ignition module and allows spark. There is a second path to ground for the kickstand relay coil that goes through a diode to the nuetral switch to ground. If that diode goes out then the only way to ground for the kickstand relay is through the kickstand switch.You may be onto something. I'm looking through the wiring diagram and circuit diagram and if one of 2 the diodes that supply current to the neutral switch failed open (no current flow), it might explain what I am seeing. I'll need to pull that diode block and test it with the wiring diagram. Good thought. I'm away from home at this time and returning in a week. I'll report back.
Quote from: 86FJNJ on Yesterday at 07:15:46 AMWhat is the ambient temperature? I had tuned my FJ in summertime and it ran perfect but when I started riding into the fall as it got colder out the 50F morning starts were difficult and I had a hanging idle that generally went away when the bike and day warmed up. I suspect it wasn't getting enough fuel with the colder ambient temps because I know it was set perfect when it was hot out.The heated garage is 60f, outside was 24f. We started the bike with the door closed (over 2k square feet in the garage bay so this isn't immediately unsafe) And after 5 minutes opened the garage door. The smoothness of the response to the throttle improved as it warmed up, but the RPM flux and slow drop persisted the entire time.
Did you recently may any other modifications like air filter or exhaust?