My 86 FJ1200 was running at the push of the button until last week. I was out of town for a week so the bike didn't get started until i came back. Now it will only start after ages of turning over and draining the battery and recharging it then trying again. The carbs were rebuilt by RPM this year so i know that's good. I have done the vacuum blow test on the petcock and gas comes out.Petcock was brand new last year from RPM also. I have spark on all 4 cylinders. The gas tank was removed and i tried drip feeding the carbs. Gas tank was cleaned and it has no rust at all so i know the carbs have no crud in them. I get the bike running at its fine runs perfectly like it should. I can switch it off restart it few hours later no problem its only happening when the bike is cold. I am at my wits end now i don't know what else to do any input would be greatly appreciated.
Do you have any ethanol in your gas? I hope not. How old?
https://www.motorcyclistonline.com/gasoline-101-lets-talk-about-e10-ethanol-fuel-for-motorcycles-tech-tips-motorcyclist-magazine-mc/ (https://www.motorcyclistonline.com/gasoline-101-lets-talk-about-e10-ethanol-fuel-for-motorcycles-tech-tips-motorcyclist-magazine-mc/)
It sounds like you have a cold start problem with your choke circuit.
It is easy to get crud in the pick up tubes that feeds fuel to the choke circuits.
Open up your float bowls for a look see.
Quote from: Pat Conlon on December 14, 2019, 04:50:51 PM
Do you have any ethanol in your gas? I hope not. How old?
https://www.motorcyclistonline.com/gasoline-101-lets-talk-about-e10-ethanol-fuel-for-motorcycles-tech-tips-motorcyclist-magazine-mc/ (https://www.motorcyclistonline.com/gasoline-101-lets-talk-about-e10-ethanol-fuel-for-motorcycles-tech-tips-motorcyclist-magazine-mc/)
It sounds like you have a cold start problem with your choke circuit.
It is easy to get crud in the pick up tubes that feeds fuel to the choke circuits.
Open up your float bowls for a look see.
I have just been using regular gas and it's 3 weeks old now. I have taken 2 of the 4 float bowls off so far and they look clean.
Next time you do a cold start, get some starter spray, open the throttle plates WFO, lift the slides and give them a squirt down the throat (close the throttle) .....see if she fires off immediately.
I still think something is wrong with your choke.
Is the choke cable working all the choke linkage correctly? Full range of motion?
Quote from: Pat Conlon on December 14, 2019, 07:37:41 PM
Next time you do a cold start, get some starter spray, open the throttle plates WFO, lift the slides and give them a squirt down the throat (close the throttle) .....see if she fires off immediately.
I still think something is wrong with your choke.
Is the choke cable working all the choke linkage correctly?
Yeah choke cable is new and the linkage works fine. I found a slight bit of brownish stuff in the bottom of one float bowl. I have drained the carbs and will use starter spray in the morning and see what happens. Thanks for trouble shooting I do appreciate it
If your fuel is only 3 weeks old, you should be fine.
Even If one float circuit is dodgy the other 3 should fire off the cold cylinders.
You have one of those electric reserve petcocks which I do not like....or trust.
Check your petcock vacuum hose connections.
I think you just need a new battery. Next time try connecting the bike when cold to the car battery or similar to check this. I had the exact same problem. I guess that when you start cranking, it sucks the battery and there is no spark or it is too weak, and like you are saying, after recharging the battery, the bike would start immediately.
When you removed the plugs to check for spark you have also removed a load from the crank - no compression. So that test in this case tells you almost nothing.
Quote from: balky1 on December 15, 2019, 03:26:57 AM
I think you just need a new battery. Next time try connecting the bike when cold to the car battery or similar to check this. I had the exact same problem. I guess that when you start cranking, it sucks the battery and there is no spark or it is too weak, and like you are saying, after recharging the battery, the bike would start immediately.
When you removed the plugs to check for spark you have also removed a load from the crank - no compression. So that test in this case tells you almost nothing.
Excellent advice Balky, you just said what I logged on to say, to the letter.
There is a point in the decline of a battery where the cranking can drop the voltage to a level that won't fire the coils, particularly on bikes that haven't had the coil relay done, even though the cranking sounds reasonable. My suggestion would be to jump start it from another vehicle, if it springs to life immediately, it is the battery.
I have observed this on a number of bikes (and a few FJ's) to the point where it is now one of the first go to checks for a bike displaying those symptoms and because it is so easily checked without any disassembly.
If this is not the problem and a lack of fuel seems like it might be the culprit, Pat is your man, he knows more about gravity fuel systems than anyone (but I think he's just being modest)
Noel
Quote from: balky1 on December 15, 2019, 03:26:57 AM
I think you just need a new battery. Next time try connecting the bike when cold to the car battery or similar to check this. I had the exact same problem. I guess that when you start cranking, it sucks the battery and there is no spark or it is too weak, and like you are saying, after recharging the battery, the bike would start immediately.
When you removed the plugs to check for spark you have also removed a load from the crank - no compression. So that test in this case tells you almost nothing.
The battery is 6 months old and it's good. I hooked up a another battery and used the jump start setting still the same. It's a fuel problem and not battery related I think .
Sounds like the choke fuel circuit is obstructed. Remove the float bowls and make sure the tiny orifice on the side of the bottom of the bowl is clear.
This is where the choke circuit draws fuel from. If it's clogged then using the choke just makes cold starting that much harder
Quote from: Scottie1 on December 15, 2019, 05:44:43 AM
Quote from: balky1 on December 15, 2019, 03:26:57 AM
I think you just need a new battery. Next time try connecting the bike when cold to the car battery or similar to check this. I had the exact same problem. I guess that when you start cranking, it sucks the battery and there is no spark or it is too weak, and like you are saying, after recharging the battery, the bike would start immediately.
When you removed the plugs to check for spark you have also removed a load from the crank - no compression. So that test in this case tells you almost nothing.
The battery is 6 months old and it's good. I hooked up a another battery and used the jump start setting still the same. It's a fuel problem and not battery related I think .
Good, you've removed first easy-to-check thing on the list. Other potential problems have been given by others.
I shall be doing everything everyone suggested to try and find the cause. It's just so annoying the bike went from starting every time without fail to what I have now.
Quote from: Pat Conlon on December 14, 2019, 04:50:51 PM
Do you have any ethanol in your gas? I hope not. How old?
https://www.motorcyclistonline.com/gasoline-101-lets-talk-about-e10-ethanol-fuel-for-motorcycles-tech-tips-motorcyclist-magazine-mc/ (https://www.motorcyclistonline.com/gasoline-101-lets-talk-about-e10-ethanol-fuel-for-motorcycles-tech-tips-motorcyclist-magazine-mc/)
It sounds like you have a cold start problem with your choke circuit.
It is easy to get crud in the pick up tubes that feeds fuel to the choke circuits.
Open up your float bowls for a look see.
I tried the starter spray and nothing just keeps cranking and not starting. I added fresh gas and still the same. Would the next check be coils? I am unsure on how to do this correctly with a multi meter.
Quote from: Pat Conlon on December 14, 2019, 07:54:47 PM
If your fuel is only 3 weeks old, you should be fine.
Even If one float circuit is dodgy the other 3 should fire off the cold cylinders.
You have one of those electric reserve petcocks which I do not like....or trust.
Check your petcock vacuum hose connections.
I think you maybe right with the cold start circuit I have eliminated all other causes. It's getting gas, got spark battery is new.
Quote from: Scottie1 on December 15, 2019, 10:53:33 AM
I think you maybe right with the cold start circuit I have eliminated all other causes. It's getting gas, got spark battery is new.
When you say, "It's getting gas" how do you know?
On the cold start "choke on" procedure, are your. plugs wet?
Smell gas in the exhaust?
Before moving on entirely from the aforementioned checks....
# Do you know how to use starter fluid
# Did you check for some positive indication the battery was getting current from the jumper battery. Of the four connections you make with jumper cables it is not uncommon to need to clean or jiggle at least one of them to get a connection. Also,
jumper leads themselves have always had a high failure rate.
# Do you know the jumper battery was good, if so, how? ( a running vehicle makes the best source )
# You say the "choke cable is new and the linkage works fine" Have you verified that now or was that the case at the time of installation?, these type of carbies will not start without choke.
Noel
After speaking with Randy at RPM he suggested cleaning the pilot jets out. Low and behold after doing that the bike fired up. I'm thinking because the gas that was in the carbs was slightly brown that the tank needs to be cleaned and that was where the problem was coming from. Thank you all for all the suggestions.
Brown gas is an important clue
Quote from: Scottie1 on December 14, 2019, 07:01:58 PM
I have just been using regular gas and it's 3 weeks old now.
Glad you got her working.... :good: