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Temperamental when warm

Started by Meltdown480, September 25, 2024, 09:44:13 PM

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Meltdown480

I'd like to preface this post by saying owning an fj is my only experience with: 1. Owning a vr bike older than 2000 2. Owning a carbureted vehicle; so excuse my ignorance. With that said, as I briefly mentioned in a reply, my bike really doesn't like starting when it's warm. I only take it to my gym about a mile away with three traffic lights in between. I stay at the gym typically an hour and by the time I end there is still noticeable heat radiating from the bike. To start it I have to give it multiple attempts with full choke and cracking the throttle. Additionally I don't have a working choke lever so I have to manually pull it on the carb so it's a little bit of a hassle. Is this normal behavior? Additionally when I was driving it back from the gym every 1-3 shift (yes I don't have second) it always went into neutral. Finally, how long does it take to warm up? When starting cold I'll hold the choke at half for about 45 seconds and sometimes when I let go it'll idle for a minute or so and then die. I'm well aware there's serious things I need to attend to but this behavior seems different to how it's been the past few months. Also I'm a broke college student so I can't really drop $2k. Any help would be appreciated.
Jackson S
1984 fj1100

Meltdown480

Forgot to mention I have the Rpm oil cooler
Jackson S
1984 fj1100

Motofun

The choke's (really it's an enrichener) function is to provide sufficient vaporized gas (along with a lot of fuel droplets) to the cylinders to allow for combustion to take place.  Once engine heat in the cylinder and more importantly in the carb bodies improves vaporization the enrichener is no longer needed.  In the cold temps this might take a minute or two...in AZ in the summer maybe 30 seconds or even less.  If your bike wont start when hot without the enrichener your engine isn't getting enough fuel through the idle circuit OR it's getting too much air through improper air in-leakage. 
1.  With the bike running try carefully spraying carb cleaner or similar combustible fluid around the carb boots.  If the engine speeds up you have air inleakage.  PS, this doesn't always work but it's cheap.
2. Fix your choke cable...really?
3. Clean your carbs, not easy for the uninitiated and kind of expensive
4. Lastly, how old or abused is the engine?  Sounds like this bike just may be tired, ie low compression, bad valves, etc.  Deffinately not cheap to fix.
Good luck
'75 Honda CB400F
'85 Yamaha RZ350
'85 Yamaha FJ1100
'89 Yamaha FJ1200
'09 Yamaha 125 Zuma
'09 Kawasaki KZ110 (grand kids)
'13 Suzuki GSXR 750 (track)
'14 Yamaha FZ-09
'23 Yamaha Tenere 7
SOLD: CBX,RZ500,Ninja 650,CB400F,V45 Sabre,CB700SC,R1

Meltdown480

I'll give it a shot, the bike has around 59k miles, I can't really speak on the condition of the engine but it feels strong. I may compression test it when I get time. Thanks
Jackson S
1984 fj1100

RPM - Robert

With 60k miles on it you will want to look at the brass ends of the choke plungers. The steel "fingers" on the choke rod wear through the brass and render the choke useless.

Motofun

Quote from: RPM - Robert on September 26, 2024, 10:26:50 AMWith 60k miles on it you will want to look at the brass ends of the choke plungers. The steel "fingers" on the choke rod wear through the brass and render the choke useless.
A cheapo fix for this is to carefully drill and tap the ends of the plungers where the tab wore off and replace the tab with a small bolt.  I did this successfully many years ago and it still works like a champ.
'75 Honda CB400F
'85 Yamaha RZ350
'85 Yamaha FJ1100
'89 Yamaha FJ1200
'09 Yamaha 125 Zuma
'09 Kawasaki KZ110 (grand kids)
'13 Suzuki GSXR 750 (track)
'14 Yamaha FZ-09
'23 Yamaha Tenere 7
SOLD: CBX,RZ500,Ninja 650,CB400F,V45 Sabre,CB700SC,R1