Temp light and running rough

V

van rock

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Howdy all and really glad to have this forum!!
I recently purchased my 85 ZL and love it!....however a few issues...related or not?
from the day my bike was dropped off the little LED warning light has been popping on and off randomly....I checked all the coolant levels and the motor never seems to run hot...not knowing the bikes history I just assumed it was a wiring issue.....while on the highway once and awhile the bike sputters and seems to run out of gas...moving the petcock from on to reserve or prime seems to "fix" the problem....so I thought...
Today while coming back from a long weekend ride I stopped and got fuel in a little town and the bike started really stuttering alot....again I assumed "bad fuel" as it rained the night before in that area I thought maybe I got some water contaminated gas....I stopped again and put in a little heat and some fresh fuel....no better and seemingly getting worse.......
Once home I noticed water boiling from the #1 plug.......uh oh!!! I promptly popped the seat and the coolant level seemed to be fine....pulled plugs and although a tad on the black side no water discoloration and seemingly no water or steam coming from the cyclinder...no water from the tailpipe?..the #4 plug did have water on the threads..any suggestions comments?.....is it head gasket time?...what else can I check to confirm no issues with motor....?
my experiance with water cooled motors is that if the head gasket is bad it will drain coolant pretty quick...it doesnt appear I've lost a drop.....another note..the bike did sit in a hotel parking lot in the rain all last night.....but ran fine 30 or so miles to the suspicious fuel station..........also I read here that a stock ZL will get 100 miles per tank??...I'm not getting a mile over 70 on a good day with a tail wind.....any suggestions or comments greatly appreciated!....have a great day!
VR
 
If the bike was left out in the rain it is very possible that some water leaked into the #1 and #4 plug wells. Dry out the well, clean the plug and put it back in and see what happens. That might explain the running rough issue, as for the intermittent warning light, that could be just a bad connection and the seeming to run out of gas thing could be that the fuel valve is not working properly.
 
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Welcome Van Rock!

You may have a tank venting problem. I had a hard time with hot restarts and that is what I found. Check the tech section for the tank venting fix.

It's a 25 year old bike, plan on giving it a good once over. If your lucky you might live close to a zl guru
 
I would definitely think you just got rain water in your plug well. The bike leans to the left when parked, and water naturally accumulates in the number 1 plug area. If the grommet around the plug boot isn't sealed well, water in the well ensues. A quick trick to see if your rough running is a venting issue is to have another key in the gas cap while you're riding. If it starts running rough going down thee road, open the gas cap and see if the problem goes away. Then you know you have to address the venting issues.
 
Hey thanks for the post guys!....I'll give it a shot and see what happens....till then have a great day!!
 
prfixer said:
I would definitely think you just got rain water in your plug well. The bike leans to the left when parked, and water naturally accumulates in the number 1 plug area. If the grommet around the plug boot isn't sealed well, water in the well ensues. A quick trick to see if your rough running is a venting issue is to have another key in the gas cap while you're riding. If it starts running rough going down thee road, open the gas cap and see if the problem goes away. Then you know you have to address the venting issues.
Click to expand...

Excellent troubleshooting technique. I would go a step further and drain the tank and yank out the petcock and clean it and the screen. Pull out the screen crefully and spray it down inside and out with carb cleaner. Give the inside of the petcock a good soak while moving the petcock lever back & forth. Its easy preventitive maintenance.
 
yep apparently just watter in the #1 hole...let it set overnight and runs like a champ!

while riding last night it sputtered and died like out of gas....popped the tank and viola! cleared right up....I'll paruse alittle and find the solution to that problem....thanks all! I really appreciate your help!!
 
Regarding your temp light problems then you are having some wire problems with the 120 degree sensor/circuit.

The 120 degree sensor is mounted at the front side of the Thermostat housing. At 120 degrees it diconnects ground to the Temp light module which turns on the Templight.
This sensor is dicontinued and not available any more. The most common problem is that the wire sticking out of the sensor gets brittle and breakes off at the sensor. There is a thread on this site where it is shown with pictures how it is possible to repair the sensor by reattaching the wire to the sensor. I have done this repair on my sensor. I could not fint the thread but it is there somewhere..
There is slight possibility that you have a loose/coroded connection somewhere on the way from the sensor to the Tach which would also show same symptoms..

The dum fix to this problem is to ground the wire from the sensor permenantly... strongly not reccomanded - unless for a temporary troubleshooting...
 
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