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
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.
  • 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

Having trouble using the Discussion Forums? Contact us for help. accepts no responsibility for forum content and requires forum participants to adhere to the rules. Click here for more information.

UN Forklift FGL18T
HANGZHOU, Zhejiang, China
New - Sale
UN Forklift FL20-32LNJX2
HANGZHOU, Zhejiang, China
New - Sale
Latest job alerts …
Mobile, Alabama, United States
Opa Locka, Miami, United States
Houston, Texas, United States
Paducah, KY, United States
Latest job alerts …
Houston, Texas, United States
Mobile, Alabama, United States
Paducah, KY, United States
Opa Locka, Miami, United States
UN Forklift FBR25NQC3
HANGZHOU, Zhejiang, China
New - Sale
Moffett M8-50.3
Flesherton, Ontario, Canada
Used - Sale

PREMIUM business

ROYPOW Technology Co., Ltd.
Manufacturer of lithium forklift battery solutions, the global leader in the market of lithium batteries replacing lead acid batteries.
Movers & Shakers
Ian Cooke Ian Cooke
Director of Academy, Lifting Equipment Engineers Association
Vice President of Manufacturing, Clark Material Handling
Vice President of Finance, Clark Material Handling
Chief Executive Officer, UK Material Handling Association