Tecumseh OHV125 surging


  #1  
Old 06-12-17, 03:28 PM
G
Member
Thread Starter
Join Date: Jun 2017
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Tecumseh OHV125 surging

Have a OHV125 which started surging bad enough to stop the engine. Replaced air filter, nonadjustable carb, did the valve clearances to .004in., tried to adjust throttle lever with no avail. Spark plug is a bit old but looks good and cleared to .030in. The flywheel and ignition coil are a bit rusty. Please help. This is driving me mad.
 
  #2  
Old 06-12-17, 03:57 PM
BFHFixit's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jun 2007
Location: USA.
Posts: 1,511
Upvotes: 0
Received 0 Upvotes on 0 Posts
.004 might be a bit tight on the exhaust, I set a tight .005 on the intake and loose .005 on the exhaust. Most specs are .003-.005 for intake, .005-.007 for exhaust...however this should not cause your surging issue. Almost always surging is caused by a lean mixture due to fuel contamination or carb issue.
 
  #3  
Old 06-12-17, 04:21 PM
G
Member
Thread Starter
Join Date: Jun 2017
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Maybe i should clean the tank and line?
 
  #4  
Old 06-12-17, 04:27 PM
BFHFixit's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jun 2007
Location: USA.
Posts: 1,511
Upvotes: 0
Received 0 Upvotes on 0 Posts
If that carb has any plastic on it, and one I am thinking of, replace the carb would be my advice...others might know this engine and carb off hand...I see very few Tecumseh's any more.
If you simply have time and want to tinker, you can still find the parts to try and rebuild/clean the carb.
Geo and cheese might chime in with other help.
 
  #5  
Old 06-12-17, 04:30 PM
BFHFixit's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jun 2007
Location: USA.
Posts: 1,511
Upvotes: 0
Received 0 Upvotes on 0 Posts
By fuel contamination I mean, water or debris or stale fuel.
 
  #6  
Old 06-12-17, 06:42 PM
G
Member
Join Date: Jun 2006
Location: United States
Posts: 2,296
Upvotes: 0
Received 31 Upvotes on 29 Posts
The problem is usually a blockage in the idle circuit, the bowl nut is the main jet for the carb remove it and clean the tiny hole near the top, I usually use the wire from a bread twist tie, refer to the pic below. Have a good one. Geo

 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: