Author Topic: GTR 350 Electrical Questions  (Read 883 times)

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Offline czmike

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GTR 350 Electrical Questions
« on: February 12, 2018, 04:28:57 PM »

Hi Davis,

I tried to reply to your message regarding this subject but you have my messages blocked.

I am happy to try and answer your questions.
Put them here and off we go.

I have a rusty GTR under restoration but have not got it running yet.

Best Regards,


Offline davis

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Re: GTR 350 Electrical Questions
« Reply #1 on: February 12, 2018, 09:23:17 PM »
Yeah Mike, I never made a conscious effort to block anyone's messages, let alone yours. Not sure how that worked.

I have a bike ready to roll out, but having electrical concerns: point timing, brand new AGM battery that died (replacement coming), and suspect new rectifier.
Point timing: Can't get the points to close properly within the given adjustment range, even with rotating the whole dynamow assembly. Triple checked gear punch mark alignments, but how well on the pinion to crank I do not recall. Just for practice I am going to assemble an engine ready for assembly on the bench and play with point timing there. If that works, then the side comes off to check pinion-crank position on the bike.
Dead battery: Bad recifier? The one I'm using is NOS. How to check to see if, and how much, drain the battery may be experiencing when installed.
Rectifier: How to multimeter test it? I disassembled a used one to test the diodes and see if I can assemble a good one out of several rectifiers. Any idea on the specifications for the individual diodes?
Condensors: Measure a little under at 19 micro Farad. They are new ones, but measuring two other new sets on the bench proved inconclusive so I took them and a used set down to the local small engine repair shop for test and they said the new ones were "good" and the used one bad.

Offline OldSwartout

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Re: GTR 350 Electrical Questions
« Reply #2 on: February 13, 2018, 06:29:57 AM »
If you suspect a rectifier, there's a good test procedure here:     

Checking with a digital multimeter doesn't work well.
Karl Swartout
Mooresville, IN
BS175 Roadracer

Offline BRT-GTR

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Re: GTR 350 Electrical Questions
« Reply #3 on: February 13, 2018, 10:58:35 AM »
          Hi Bob,
       RE - Points timing ---  The crank pinion is timed to the crank on one of six splines, the correct one being identified by the dot punch on the crank end. So the timing would be at least 60 degrees out if the wrong spline was used.  (The crank dot is also in line with the disc drive pin and the big end).  This might help you determine if you need to strip the engine drive side.

     I initially struggled to get the points timing right on my GTO. Could only get it lined up on the timing pin with the alternator and points plate slots turned to the end of their adjustment. Even then there was a few degrees difference between the two points.       Carefully checked the timing punch marks a couple of times while dealing with other issues on.
     It was only when I pulled the alternator off the engine that I accidentally found the problem.................the alternator drive gear was jammed on its key and was at least 4mm out from being fully seated on its taper, was running skewed and displaced enough to throw the timing out.     Did the engine builder know about this.........probably, the shaft, gear and retaining screw were smothered with hardened loctite. That's what led me to investigate.
    Chipped the loctite off, eased the key in its slot, put it all back together correctly with a new set of alternator bearings and it timed up perfectly on both points.
   Not saying this is your problem but something to bear in mind, there's not much else it could be.
        Good luck,      Brian.

   P.S. Bob, I assume you mean't to say ''Can't get the points to 'open' properly ........range''
« Last Edit: February 15, 2018, 08:57:49 AM by BRT-GTR »
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