Komatsu FG25ST-12:
No start - vacuum issue

Let me start by saying I am in no way a mechanic but I know enough to get myself in trouble lol.

I have a 2000 Komatsu FG25ST-12 with a propane Nissan engine. I had issues with the machine starting but immediately shutting off. I had my mechanic come onsite for a brief look and he suggested a vacuum issue and to change the LPG converter. I changed the converter module as well as the lockoff module. Hooked everything back up and still same issue. If I disconnect the vacuum hose on the converter and suck on it while turning over it fires right up, then shuts off again as soon as I stop.

Obviously I have a vacuum issue but I'm not certain where to go from here and am trying to minimize my mechanic call out bills. :)

Thanks in advance for any feedback/help.
  • Posted 19 Jan 2022 09:03
  • Discussion started by PETER
  • Alberta, Canada
- PETER
Showing items 1 - 2 of 2 results.
Hello Peter, control the governor. It's mounted below the carburator and it's got a 3 screws cover, inside there's a spring witch controls the maximum RPM. I think the spring is broken and the valve stays closed.
Regards
Marcb
  • Posted 22 Jan 2022 01:00
  • Reply by marcb
  • ANTWERP, Belgium
I would look at carb make sure plunger inside is moving when cranking if stuck will not allow any propane to converter hope this helps
  • Posted 21 Jan 2022 02:47
  • Reply by Scott_
  • Pennsylvania, United States
Scott

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