OP
@rob_g avatar
UTC

Hooked
2008 GTS250, 2009 S150, 2017 GTS300Super, 2006 GT200
Joined: UTC
Posts: 348
Location: Houston
 
Hooked
@rob_g avatar
2008 GTS250, 2009 S150, 2017 GTS300Super, 2006 GT200
Joined: UTC
Posts: 348
Location: Houston
UTC quote
My GTS250 had been down a couple/few years and I recently got it going again. Prior to its years long rest I'd installed a big bore kit and malossi head so the motor was out. Here recently I replaced the fuel pump. It was now running really well. Since I intend to make it my next project (take it apart for painting) it's been sitting and I'd go out and run it every few days.

One day it wouldn't start. Couldn't figure out why. Battery is at 100% and 12.x volts. Playing around tonight with a power probe I discovered using the negative grounding lead all power was restored if I touched it to the motor or any metal part.

Somethings loose somewhere and I don't know/remember where to look. For the wrenchers, what would you check first and where is it? Ideas? It has to be a grounding problem. With the key switched on if I ground it with the power probe device the fuel pump and lights kick on and all seems normal but when I take it off, completely dead.
@greasy125 avatar
UTC

Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14899
Location: The state of insanity, SoCal
 
Sergeant at Arms
@greasy125 avatar
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14899
Location: The state of insanity, SoCal
UTC quote
I'd suspect the main ground that attaches to one of the starter mount ears. after that, maybe the frame to engine ground that's on the left side strut of the engine bay. after that, I'd rattle the main harness from the stator forward and see if something is loose in there.
OP
@rob_g avatar
UTC

Hooked
2008 GTS250, 2009 S150, 2017 GTS300Super, 2006 GT200
Joined: UTC
Posts: 348
Location: Houston
 
Hooked
@rob_g avatar
2008 GTS250, 2009 S150, 2017 GTS300Super, 2006 GT200
Joined: UTC
Posts: 348
Location: Houston
UTC quote
Thank you greasy. I'll look in those places.
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