Power Loss

Started by WGuaire, March 09, 2020, 11:12:03 AM

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WGuaire

1983 Vision.
I was riding on an interstate, about 65 mph. All at once the throttle got weak and the tachometer went to zero as I was moving. The motor had revs, but I felt ignition or throttle was weak. There was an exit close ahead. As I pulled off for the exit, I switched the pet cock to RES. I knew I had fuel but I wanted to eliminate a potential fuel starvation. The motor kept running.
  A mile or so later, I was able to put in 1.3 gallons. The problem never came back. I'm thinking the problem was electrical, not fuel related. I can't figure out what would cause a temporary cut off like that.
The AGM battery is new and I had charged it yesterday. My reg/rec is new. I do have an added accessory fuse box, PC-8.
Have I invented a new problem?

Walt_M.

A couple of things come to mind, fuel tank vent and rev limiter but neither would necessarily cause the conditions you describe but are relatively easy to fix. The tank vent is a tiny hole in the filler neck. If it's plugged you would have noticed when you took off the fuel cap. The rev limiter cuts spark to the front cylinder if it detects over-rev or fails and thinks it does. The Y/b wire at the TCI can be disconnected to prevent this. Some people just cut this wire but it's easy enough to release from the plug and pull it.   
Whale oil beef hooked!

jefferson

Since the tachometer went to zero and the engine was still running points to electrical. You for sure need to pull the rev limiter wire out of the plug and see what happens then.

WGuaire

Thanks for the help.
  I was thinking the negative terminal may have stopped working for a few seconds. Something electrical made the tach drop its reading.
Where is the rev limiter wire? How do I pull it out while the engine is running?
The motor was running less than 6000 rpm when the drop out happened.
Bill

fret not

The wire connects to the tach on the back side, and to the ignition 'box'.  Rather than cutting it just disconnect it.  The result is the same but by not cutting the wire it 'can' be restored to original. :police:
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

jefferson

No need to pull it out when the engine is running. The color of the wire is in Walts post.  Make sure the cables at the battery are clean and tight and then the other end of those cables also.

WGuaire

I cleaned up the ground strap connector. Put some Ox-gard on the exposed copper. Goobed everything with di-electric grease. Got out for a ride and didn't have a repetition of the power drop. If it happens again, I'll go after the 'yellow wire'. Thanks for the help, Bill

Kenny

  Back in the late eighties I had a similar problem on my 82 (the green one with the Hannigan fairing.
    At freeway speed the engine would suddenly cut out partially ,so I would pull over to the side of the road get off and see if I could find the problem . I tried several things changing the fuel setting, opened the tank cap, switched the kill switch off and on. Then would get back on the bike and it would start up with no issues. This occurred several times and I could not find the fault, finally it hard faulted and would not start & I found the Side Stand Switch was the issue.
      Hope this helps.
     Cheers Ken  ;) 
2 XV 920rh 81
1 Red/White 83
1 Blue/White 83
Bmw R100rs 84
TDM 850  92

WGuaire

I also have a Royal Enfield 2014 Continental GT 535. The side stand switch is removed.