Clutch's 1982 KZ750 E3 Cafe

Motor Head wrote: So it is staying ON? That might be because of the small resistance still in the Thermistor. Maybe wire it up to either a relay or a transistor to switch it, on/ off.

Ok, I consider myself to be pretty good at wiring things, but I'm no electrical engineer. LOL! :silly: Can you explain how I would wire the relay or transistor to fix the problem? Also, would one of those inline resistor thingies (that's the technical term :woohoo:) that are used to run led turns with stock flasher units possibly solve the problem as well?

EDIT: It should definitely have been OFF with all the gas I had in it (probably about 3 gallons), so I'm thinking maybe the LED issue is the problem.

clutch wrote:

clutch wrote: A little update on the gasket stuff. So far it hasn't set completely, though I am just looking at the squeeze out. It is still a little on the pasty side, but it has been cold here. I think leaving it until Monday will be a good idea, but I will check on it again tomorrow to see if it looks to be curing.

I just went out to the garage and tried to torque the adapter plate bolts down a little more. They are as tight as they will go, so I'm hoping that means the gasket material has set. If I have a little time before work tomorrow, I will put some gas in it to see how it holds up...if not, I will do it on Monday. Either way, I will update on how well the stuff sealed the tank for me.

Poured the gas back in the tank today. First a little, then a thorough check to see if it was leaking. Then I poured the rest. 20-30 mins after refilling it, there is still no leak as checked by rubbing a dry finger around the edge of the plate, over the mounting bolts and around the petcock itself. Hopefully this stuff will hold strong for a while! So initially, my thought is that the Permatex No 1 gasket material is the thing to get to seal a petcock adapter plate!

WTF!!??!??!?!?!?!?!?!?!?

DON'T USE PERMATEX NO 1 ON GAS TANKS! IT IS COMPLETE CRAP THAT IT IS GAS RESISTANT. I let this stuff cure for THREE DAYS and this is about an hour after putting gas back in my tank...this is plain ridiculous for something that is supposed to be gas resistant!!!!!

clutch wrote: WTF!!??!??!?!?!?!?!?!?!?

DON'T USE PERMATEX NO 1 ON GAS TANKS! IT IS COMPLETE CRAP THAT IT IS GAS RESISTANT. I let this stuff cure for THREE DAYS and this is about an hour after putting gas back in my tank...this is plain ridiculous for something that is supposed to be gas resistant!!!!!

Yikes! :pinch:
Is all that gasoline?
And all from leak where petcock attaches to the fuel tank?

This looks worse than it was without any sealant.

Once used Permatex #2 (stays slightly soft and flexible) on a partially stripped carb drain plug, which eliminated gasoline leakage for several days before the new plug arrived.

Yellow (instead of white) teflon tape is supposedly more fuel resistant.
There is also a dedicated "fuel line sealant" available at auto supply stores.

Isn't there a rubber o'ring or gasket between the adapter and tank?
And perhaps another o'ring where the petcock screws into the adapter plate?

For comparison, the stock Z1 and KZ900 have a threaded bung protruding from bottom rear of fuel tank, to which a two-way nut attaches the petcock. In the center of the nut is an internal o'ring that the nut simultaneously tightens against both the bung and the petcock, which creates a leak-proof seal.

Without the rubber o'ring inside the two-way nut, the fitment would leak like crazy.

Good Fortune!

Yes it's ALL gas! There is no rubber gasket either on the petcock itself, or on the plate. The leak is from the adapter plate to gas tank seal (or lack thereof). The threaded petcock seal is good. I am debating using JB Weld to seal, and permanently mount, the adapter plate. Also, I started a new thread about this permatex failure in the tools section:

kzrider.com/forum/21-tools/486262-permat...gasket-maker-is-crap

SO I went out to the garage again to remove and clean up the adapter plate, petcock, and bolts. There was basically no gasket material left...the gas ate right through it! The little amount of gasket material that was still there had changed from the reddish-brown color to a white/off white color...must have been a chemical reaction to the gas, or the ethanol in the gas. In any case, it's all clean and drying so when I figure out what method I will be attempting next, it will be ready to wipe down and go!

i have had this issue before but with a stock petcock, i went to the local hardware store and bought a gasket making kit, came with cork, rubber and a fiber material, i used the rubber and made a template as best i could and cut the holes out with an xacto knife and it has worked great for me. i think 5 bucks for the kit and some time making it fit right and its as good as gold.

I did a little research and found a rubber material that is ethanol and gas resistant. It's nitrile rubber, also called buna n. I ordered a sheet of the material and will be making a gasket out of that when it arrives. Hopefully it will hold for a good long while before I have an issue with the gas tank again!

.

clutch wrote:

Motor Head wrote: So it is staying ON? That might be because of the small resistance still in the Thermistor. Maybe wire it up to either a relay or a transistor to switch it, on/ off.

Ok, I consider myself to be pretty good at wiring things, but I'm no electrical engineer. LOL! :silly: Can you explain how I would wire the relay or transistor to fix the problem? Also, would one of those inline resistor thingies (that's the technical term :woohoo:) that are used to run led turns with stock flasher units possibly solve the problem as well?

I just read about this but couldn't find the thread..I'm rewiring my bike as I speak.. the LED's run on lower juice, and there is a certain amount of transference between the indicators/lights that does not effect 'normal' lights.. because they require a higher current-the fix was to put a diode in to split the power after the switch. The switch itself allows leakage.
Not technical I know but pretty sure that should fix it.

richw wrote:

clutch wrote:

Motor Head wrote: So it is staying ON? That might be because of the small resistance still in the Thermistor. Maybe wire it up to either a relay or a transistor to switch it, on/ off.

Ok, I consider myself to be pretty good at wiring things, but I'm no electrical engineer. LOL! :silly: Can you explain how I would wire the relay or transistor to fix the problem? Also, would one of those inline resistor thingies (that's the technical term :woohoo:) that are used to run led turns with stock flasher units possibly solve the problem as well?

I just read about this but couldn't find the thread..I'm rewiring my bike as I speak.. the LED's run on lower juice, and there is a certain amount of transference between the indicators/lights that does not effect 'normal' lights.. because they require a higher current-the fix was to put a diode in to split the power after the switch. The switch itself allows leakage.
Not technical I know but pretty sure that should fix it.

Cool thanks for the info

Nice thread Clutch.........i've just found it! DOH!!!

Bike is looking really well, just a thought, why dont you paint your fork bottoms black to freshen them up...........after you kick the nuts off your petcock though.