Hello
I'm having this strange problem with my gl1200 1986 . it can be running for hours in city rides and run well . when i take highway , after about 40 km (25 mils) the engine start working bad and the bike is hardly running . feels like low fuel supply .
I checked in real time and spark is reaching to all plugs . fuel pump is letting fuel out .
Carburetors been cleaned lately
the old fuel filter has been removed
I suspected the fuel pump and replaced it for a new non original one . this one stopped supplied fuel after this millage so i change for the original again ..
i would be glad to here ideas about it .
thanks
Ok.Next test..Run it around...run it where it starts to act up...Throttle back to a slower speed like you were back in town..after a minute or so does it recover and run good again?
Of it does,there is a fuel volume delivery problem...Not enough fuel being pumped into the carbs for the highway demands but just enough for in town riding.
Has the fuel filter been replaced?
Fuel filter has been removed . one of the times the problem appeared i stopped , took the filter out and the bike went smoothly . but just for that ride .
I was thinking about this two options :
bad coils : i have spark when the problem is on .
floats height : indeed i did carburetors work so perhaps can be the problem . on the other hand , how come it runs so good for long distance if so ?
After it acts up does it return to normal if you get it back to slower town driving or does just stay bad.
Trying to determine if the problem is isolated to the highway drive or once it acts up it stays that way til it's cooled off.
Good information.Because of the "rest" duration,you should be able to eliminate the entire fuel system.It would have recovered pretty quickly if it was low on fuel flow.
My thoughts are electrical.
Next test..You need a volt meter attached to the bike monitoring the volts between the frame and the ignition system.You can pick the black wire on the ignition module for positive and green for the ground.Do not hook it to the battery.
I'm wondering if there's enough voltage to keep the spark really hot of or if it's getting weak due to a battery/ charging or ground problem causing a low voltage.
Expect the voltage to be between 13.5_14.2 volts when above 3000 rpm.
Also do look very close to the battery for a connector with 4 small wires in it.Disconnect and clean any corrosion you see.There the pulse coil wires and subject to corroding.
HI . by ignition module do you mean CID ?
What small wires in battery do you mean ?
Do you think about possibility of low charge to battery that cause this ?
Yes the cdi..ignition module...whatever name you'd like to call it...Measure the volts right at the plug...both power and ground....The small wires do not attach to the battery...it's a small plug next to it.It has 4 wites in it.there the pulse coil connection.
I'm interested if the voltage is dropping at the ignition module causing a poor spark...The next day the battery recovers enough to get it started again and the volts stay up for a while....
Do you have any "extra" lights on the bike...Ex...2@ 55watt driving lights will slowly discharge the battery while driving..
I did all these electrical checks and everything seemed to be ok .
Went on a ride again the bike run ed well for 50 km (36 miles) , I stopped for gas and than it began to work poorly . took the spark plugs cups out and realized cylinder front right is not working . no fuel in the carburetor float chamber . rode back on 3 cylinders work .
i intend to take carburetors out for a check .
A chance that weak fuel pump can be cause ?
I had that very same problem. I took the right carbs off and cleaned them and they were good for a short time. I repeated the process and again it was good for a little while. Then I went on ebay and found someone with new float valves and bought two of them. When they arrived I removed the right carbs again and changed the float valves, adjusted the float level and have never had any trouble again.
Russell
Those who say it cannot be done should try not to interrupt those who are doing it.
