Hawk fuel gauge problem and interesting finds

LunaTech · 09-03-2016, 09:49 PM

So, I decided to try and figure out why my fuel gauge is showing full or just bouncing around. I checked all the plug connections and it magically started working. Added some gas to bring it to about 1/2 tank and took it for a ride. The vibration caused it to start acting funny again and the it just started showing full again. Get home and remove the tank again with the intention of checking/removing the float when I got this idea. Let just drain the tank through the petcock (yea I had the time to kill) and see where the fuel level is compared to the float. Well if the gauge worked (still working on that) it would read dead empty before you go on reserve. The fuel level is well below the float when the fuel stopped flowing out the petcock. So then I get the bright idea to see how much fuel is left when you switch to reserve. So I get a clean empty milk jug and switch to reserve and let it drain. After the fuel stopped flowing I had approx. 1/3 of a gallon. I could have probably gotten a little more but not much. So if you go to reserve you better be finding a place to fill up pretty quick.

I haven't pulled the sender unit from the tank yet (kids were hungry). I did monitor the resistance while it was draining and it was slowly went up as the fuel level dropped so it appears to be working but I'm going to remove it and inspect it. Also going to inspect all the connections (probably redo them). I'll keep you all posted on what I find.

hertz9753 · 09-04-2016, 12:58 AM

http://www.chinariders.net/showpost....6&postcount=67

I just unplugged mine but pc did that.

LunaTech · 09-04-2016, 04:54 PM

Well I ended up remaking the connector at the sending plug (the one you have to unplug to remove the tank). Remade both end using Molex connectors. Filled up to 1/4 tank and went for a short ride. So far all is good. Just filled up and going on a longer ride this evening. Hopefully it's fixed. I'll chime in later and let you all know how it goes.

@dacs57: I've also checked both my Hawks speedos with my GPS and both are pretty much right on the money. As close as any other bike I've had. I have noticed there is a little lag, meaning the speedo has to "catch up" to your speed but it's fairly nominal.

pcspecialist · 09-04-2016, 05:02 PM

I had two problems with mine, here's the first that was resolved with a digital cluster from you know who:

And then there was also an incorrect sending unit which I replaced with one from CSC. On the left is the "fuel sensor" I purchased from CSC and on the right is the one that came with my Hawk. The one that came with my Hawk wasn't even bent correctly. The bend you see is what I did prior to getting the one from CSC, and wouldn't you know it, my bend almost matches CSC's. On the stock sending unit, I also corrected the bend that angles the float away from the center of the tank because it would hit the ∩ and get stuck. CSC's didn't need any adjustments to any bends.

The gasket that came with the CSC one is 1000x better than the friggin O-ring that is stock with the Hawk. The O-ring is a real PITA to get properly lined up with the tank on it's side (with some gas still in it).

http://www.cscmotorcycles.com/TT250-...-p/zt8-113.htm

LunaTech · 09-04-2016, 05:12 PM

I was going to the gauge cluster next as that is the most logical next step. I started with the connector I did because it started working after I unplugged/plugged it. We'll see how it goes. I've been wanting to order the digital gauge from you know who but all in good time.

**JerryHawk250** · 11-02-2016, 08:21 AM

Quote:

Originally Posted by LunaTech

Well I ended up remaking the connector at the sending plug (the one you have to unplug to remove the tank). Remade both end using Molex connectors. Filled up to 1/4 tank and went for a short ride. So far all is good. Just filled up and going on a longer ride this evening. Hopefully it's fixed. I'll chime in later and let you all know how it goes.

LunaTech, I have the same issue with my gauge. Is the gauge still working after remaking the connections? Don with APSCUSA is sending me out another sending unit to see if that corrects the problem. I've unplugged and plugged it back and would work like you until I take a ride then would go past full even with a 1/2 tank. I also checked the wire connection at the cluster and all 3 screws were loose. If remaking the connectors is all I need to do would be great.

LunaTech · 03-02-2017, 04:54 PM

Well I know this is a little old but my fuel gauge woes still haunt me. I did get a digital cluster and all seemed well but today it started reading empty when it wasn't (about 1/4 tank). I filled it up and still reading empty. I'm going to check the wiring from the sending unit to the cluster and if all is good then I'm going to replace the sending unit with one from CSC like pcspecialist did and see if that fixes it. If it's not wiring then it has to be either a bad/flaky rheostat on the stock sending unit or faulty gauge cluster and I'm betting on the rheostat if the wiring is good. I'll try to remember to keep you posted on what fixes it.

**JerryHawk250** · 03-02-2017, 05:05 PM

Quote:

Originally Posted by LunaTech

Well I know this is a little old but my fuel gauge woes still haunt me. I did get a digital cluster and all seemed well but today it started reading empty when it wasn't (about 1/4 tank). I filled it up and still reading empty. I'm going to check the wiring from the sending unit to the cluster and if all is good then I'm going to replace the sending unit with one from CSC like pcspecialist did and see if that fixes it. If it's not wiring then it has to be either a bad/flaky rheostat on the stock sending unit or faulty gauge cluster and I'm betting on the rheostat if the wiring is good. I'll try to remember to keep you posted on what fixes it.

Check to make sure your tank is not grounding out to the frame. I had the same issue and it turned out that from the factory they had installed the rubber isolator on top the tank instead of between the tank and frame. This is how it was installed from the factory. A quick way to test it is to just remove the bolt and lift the tank off the frame to see if it works again. That's how I figured it out that it had to do with the tank grounding out.

LunaTech · 03-02-2017, 10:27 PM

Never thought of that. I'll check it tomorrow.

timcosby · 03-02-2017, 10:50 PM

just took my tank off yesterday and i have no rubber top or bottom?????

**JerryHawk250** · 03-03-2017, 08:03 AM

Quote:

Originally Posted by LunaTech

Never thought of that. I'll check it tomorrow.

Hope that's all it is. It drove me crazy trying to figure it out. I even put a new sending unit and did the same thing. But like you said if you have to replace it get one from CSC.

LunaTech · 03-03-2017, 04:13 PM

Well I found that the sending unit is bad. The resistance would go between reading really low to open to correctly to open again. I just ordered a couple new ones from CSC. Hopefully the new ones from CSC will fix the problem.

LunaTech · 03-04-2017, 04:42 PM

Well I couldn't leave well enough alone. I got to messing with the sending/float unit and found that where the yellow wire connects on the bottom of the sending unit had a flaky crimp/connection so I just soldered it. Working flawlessly for now. I've still got the new units from CSC on the way but I'm gonna see if that fixes it.

Musictrek · 03-26-2017, 02:15 PM

Hello LunaTech, I have the new digital cluster. I had filled the tank but the gauge didn't register full. Its also really not empty when its on the last bar and the flashing gas pump starts blinking. I checked the range of motion of the float and its un-obstructed. So, the way it is now. It would never read full when it really would be when I fill up. you mentioned resistance which that must be the key to this. Any idea what kind of ohms value it would take to get the tank to read full?

Musictrek · 03-26-2017, 02:56 PM

I measured the res on the sending unit. I get 86.1 ohms on the bottom float position and 20.6 ohms on the top position of the float. I'm thinking to get the gauge to read full. Maybe the ohms need to read 15? I don't know the spec on the cluster. that would be the thing to figure out. Then figure out how to change the resistance of the sending unit.

09-03-2016, 09:49 PM	#1
LunaTech Join Date: Jul 2016 Location: Jonesville, NC Posts: 136	Hawk fuel gauge problem and interesting finds So, I decided to try and figure out why my fuel gauge is showing full or just bouncing around. I checked all the plug connections and it magically started working. Added some gas to bring it to about 1/2 tank and took it for a ride. The vibration caused it to start acting funny again and the it just started showing full again. Get home and remove the tank again with the intention of checking/removing the float when I got this idea. Let just drain the tank through the petcock (yea I had the time to kill) and see where the fuel level is compared to the float. Well if the gauge worked (still working on that) it would read dead empty before you go on reserve. The fuel level is well below the float when the fuel stopped flowing out the petcock. So then I get the bright idea to see how much fuel is left when you switch to reserve. So I get a clean empty milk jug and switch to reserve and let it drain. After the fuel stopped flowing I had approx. 1/3 of a gallon. I could have probably gotten a little more but not much. So if you go to reserve you better be finding a place to fill up pretty quick. I haven't pulled the sender unit from the tank yet (kids were hungry). I did monitor the resistance while it was draining and it was slowly went up as the fuel level dropped so it appears to be working but I'm going to remove it and inspect it. Also going to inspect all the connections (probably redo them). I'll keep you all posted on what I find.
	0

09-04-2016, 12:58 AM	#2
hertz9753 Join Date: May 2016 Location: Bismarck, ND Posts: 868	http://www.chinariders.net/showpost....6&postcount=67 I just unplugged mine but pc did that. __________________ 2015 and 3/4 RPS Hawk 250. Most people would call it a 2016 but the MCO didn't.
	2

03-02-2017, 10:50 PM	#10
timcosby Join Date: Nov 2016 Location: robertsdale alabama usa Posts: 1,007	just took my tank off yesterday and i have no rubber top or bottom????? __________________ 1991 harley heritage softail classic 2016 hawk kaw h1 400 tripple 13' long chopper in progress 2009 johnny pag bar hog 2004 hd electra glide ultra classic shriner edition 1997 harley davidson 1200 sportster 1972 harley davidson amf sx250
	0

09-04-2016, 04:54 PM	#3
LunaTech Join Date: Jul 2016 Location: Jonesville, NC Posts: 136	Well I ended up remaking the connector at the sending plug (the one you have to unplug to remove the tank). Remade both end using Molex connectors. Filled up to 1/4 tank and went for a short ride. So far all is good. Just filled up and going on a longer ride this evening. Hopefully it's fixed. I'll chime in later and let you all know how it goes. @dacs57: I've also checked both my Hawks speedos with my GPS and both are pretty much right on the money. As close as any other bike I've had. I have noticed there is a little lag, meaning the speedo has to "catch up" to your speed but it's fairly nominal.
	0

09-04-2016, 05:02 PM	#4
pcspecialist Join Date: May 2016 Posts: 583	I had two problems with mine, here's the first that was resolved with a digital cluster from you know who: And then there was also an incorrect sending unit which I replaced with one from CSC. On the left is the "fuel sensor" I purchased from CSC and on the right is the one that came with my Hawk. The one that came with my Hawk wasn't even bent correctly. The bend you see is what I did prior to getting the one from CSC, and wouldn't you know it, my bend almost matches CSC's. On the stock sending unit, I also corrected the bend that angles the float away from the center of the tank because it would hit the ∩ and get stuck. CSC's didn't need any adjustments to any bends. The gasket that came with the CSC one is 1000x better than the friggin O-ring that is stock with the Hawk. The O-ring is a real PITA to get properly lined up with the tank on it's side (with some gas still in it). http://www.cscmotorcycles.com/TT250-...-p/zt8-113.htm
	0

09-04-2016, 05:12 PM	#5
LunaTech Join Date: Jul 2016 Location: Jonesville, NC Posts: 136	I was going to the gauge cluster next as that is the most logical next step. I started with the connector I did because it started working after I unplugged/plugged it. We'll see how it goes. I've been wanting to order the digital gauge from you know who but all in good time.
	0

03-02-2017, 04:54 PM	#7
LunaTech Join Date: Jul 2016 Location: Jonesville, NC Posts: 136	Well I know this is a little old but my fuel gauge woes still haunt me. I did get a digital cluster and all seemed well but today it started reading empty when it wasn't (about 1/4 tank). I filled it up and still reading empty. I'm going to check the wiring from the sending unit to the cluster and if all is good then I'm going to replace the sending unit with one from CSC like pcspecialist did and see if that fixes it. If it's not wiring then it has to be either a bad/flaky rheostat on the stock sending unit or faulty gauge cluster and I'm betting on the rheostat if the wiring is good. I'll try to remember to keep you posted on what fixes it.
	0

03-02-2017, 10:27 PM	#9
LunaTech Join Date: Jul 2016 Location: Jonesville, NC Posts: 136	Never thought of that. I'll check it tomorrow.
	0

03-03-2017, 04:13 PM	#12
LunaTech Join Date: Jul 2016 Location: Jonesville, NC Posts: 136	Well I found that the sending unit is bad. The resistance would go between reading really low to open to correctly to open again. I just ordered a couple new ones from CSC. Hopefully the new ones from CSC will fix the problem.
	0

03-04-2017, 04:42 PM	#13
LunaTech Join Date: Jul 2016 Location: Jonesville, NC Posts: 136	Well I couldn't leave well enough alone. I got to messing with the sending/float unit and found that where the yellow wire connects on the bottom of the sending unit had a flaky crimp/connection so I just soldered it. Working flawlessly for now. I've still got the new units from CSC on the way but I'm gonna see if that fixes it.
	1

03-26-2017, 02:15 PM	#14
Musictrek Join Date: Jan 2017 Location: Arizona Posts: 463	Hello LunaTech, I have the new digital cluster. I had filled the tank but the gauge didn't register full. Its also really not empty when its on the last bar and the flashing gas pump starts blinking. I checked the range of motion of the float and its un-obstructed. So, the way it is now. It would never read full when it really would be when I fill up. you mentioned resistance which that must be the key to this. Any idea what kind of ohms value it would take to get the tank to read full?
	0

03-26-2017, 02:56 PM	#15
Musictrek Join Date: Jan 2017 Location: Arizona Posts: 463	I measured the res on the sending unit. I get 86.1 ohms on the bottom float position and 20.6 ohms on the top position of the float. I'm thinking to get the gauge to read full. Maybe the ohms need to read 15? I don't know the spec on the cluster. that would be the thing to figure out. Then figure out how to change the resistance of the sending unit.
	0