quawk
2nd Gear
Posts: 150
|
Post by quawk on Jun 30, 2022 10:12:02 GMT -5
After riding my bike recently, upon returning home and stopping, I noticed coolant leaking from the front area of the bike. After running it up to temp another time and seeing more coolant leak out, I started to investigate the problem. Looked like it may have been coming from the filler neck/expansion tank area so I removed the fuel tank and found that as I expected the connection of the small elbow shaped nipple coming off of the top radiator neck that I had tried repairing with JB Weld some time ago had failed. So I bit the bullet, removed the radiator and took it to a welding shop and had the tube/nipple tig welded back on. Upon reinstalling and riding, I was still seeing coolant loss when I pulled in. Almost looked like the radiator core itself may have been leaking. So tank back off and looking things over again, the small hose from the above mentioned tube that connects to the lower expansion tank tube, although it didn't seem like it had failed, it was very soft and spongy. I replaced it with windshield washer/vacuum hose which I realize isn't necessarily the correct hose to use, but for at least a temporary fix seems to have stopped the coolant leak problem. The thing is now when I ride long enough to get it up to operating temp the gauge seems to stay at about the 3/4 white hash mark. The fan does switch on as the needle approaches that 3/4 mark and seems to stay on but doesn't bring the temp down on the gauge or enough to switch the fan back off. I know the normal operating temp subject has been discussed in other posts, but I guess what I'm asking is, where do others' bikes run at normal or usual operating temp. It is summer here where I live and is warm but not extremely so when I went for a ride. And I am aware that the rotary generates a great deal of heat but running what I feel is dangerously close to the red area on the gauge (overheating) is unnerving. Any comments or input from others who ride regularly would be appreciated.
|
|
|
|
Post by wayne on Jun 30, 2022 19:01:56 GMT -5
|
|
|
|
Post by Framitron on Jun 30, 2022 20:26:40 GMT -5
You can take a quick look at your sparkplug to see if you are running in a lean condition.
My bike did that briefly when I had a partially clogged fuel filter. As I rode up a long steep hill leaving town I saw the temp gauge slowly creep up into the very hot part of the dial. Quickly pulled over and let it cool down. Rode home slowly and fixed the fuel filter issue. All good after that.
|
|
quawk
2nd Gear
Posts: 150
|
Post by quawk on Jul 1, 2022 9:19:15 GMT -5
Can someone tell me where the 7 volt regulator for the temp gauge is located on the 1976 A model bike? In the instrument cluster somewhere I assume? Honda used a 7 volt regulator for supply voltage to the temp and fuel gauge on some of their 70s bikes (Gold Wings). If both were wonky at the same time it was a good indicator the regulator had failed.
|
|
quawk
2nd Gear
Posts: 150
|
Post by quawk on Jul 1, 2022 10:23:38 GMT -5
Framitron, thanks for the suggestion. Pulled the spark plug and I'm no expert at plug reading but it looks to be running in a normal condition. No indication, to me anyway, of running lean. Pulled the fuel line at the carb and opened the petcock and have full flow out of the hose. Removed the inlet fitting at the carb and checked the internal screen and it is clear and open. Don't suspect it to be running lean. When running the bike pulls and runs in what I feel like is a normal condition.
|
|
|
|
Post by timpa136 on Jul 1, 2022 14:32:01 GMT -5
Quawk,
Agreed our bikes quickly jump in temperature if too lean but you will know that for sure.
I would suggest a infra red Thermometer such as Wayne has posted in his video and with the bike at circulating temperature and a fan at the front, many times one will see a cool zone indicating a clogged core while reading different areas of the radiator.
Tim
|
|
quawk
2nd Gear
Posts: 150
|
Post by quawk on Jul 1, 2022 14:47:29 GMT -5
Tim, as I asked above could you or anyone tell me where the 7volt temp gauge regulator is on the '76 A model? Have the instrument cluster off and apart and am not finding it. Hope I'm not missing the obvious.
|
|
|
|
Post by hudson on Jul 1, 2022 17:24:28 GMT -5
I think the A model has the voltage regulator internally as part of the gauge. ( CVR Constant Voltage Regulator ) Should be the same as a GT750 of the same year. If you can find a GT manual to take a look at it should have the diagnostic information. I have not seen any information in a RE manual on an A model temp. gauge. The parts book I've looked at shows a different sending unit sensor for an A or M model so that does indicate different specs for the gauge. 1976 "A" model sensor is the same part number as the GT 750 and shows that it is still available. Good luck, please let us know what you learn.
Brian
|
|
quawk
2nd Gear
Posts: 150
|
Post by quawk on Jul 1, 2022 17:54:50 GMT -5
Brian, thanks for the response. As I messaged previously, have the gauge cluster off and apart (to a degree) and I see no separate/external device. I do have a service manual printing date Aug. '74 which I assume is for the '75 M model. Other posts about factory info and service manuals and bulletins seems to indicate conflicting info if you weren't involved at the dealership level or above. I've wrenched for a lifetime but am still "learning" on this one. For now, all I want to figure out is why is this thing is running hotter than it should. Your response of having an internal Constant Voltage Regulator would explain why I'm not finding a separate regulator. Thanks again and I welcome any other input on this.
|
|
]
