Jump to content

Nominations for Tractor of the Month
Garden Tractors and Parts on eBay



Photo
- - - - -

Case 444 loses power


  • Please log in to reply
7 replies to this topic

#1 MNGB ONLINE  

MNGB
  • Senior Member
  • Member No: 62466
  • 994 Thanks
  • 824 posts
  • Location: Minnesota

Posted June 03, 2015 - 01:05 PM

Hi all, went out to mow and after about 5 minutes the engine loses power like the throttle is backed off to 1/2 or less has done it 3 /4 times if it sits for a few minutes it will run up to full r"s but trying to mowing and it loes R's, I'm thinking maybe the fuel pump is not supplying enough fuel what do you all think?

Its a K321 14 hp been running great starts right off.



#2 boyscout862 ONLINE  

boyscout862
  • Senior Member
  • Member No: 8923
  • 9,763 Thanks
  • 7,532 posts
  • Location: N.E. Connecticut

Posted June 03, 2015 - 02:30 PM

Check fuel flow at the carb. Pump could be the problem but could also be plugged; line, filter, or tank outlet. Check the spark too. Good Luck, Rick


  • MNGB said thank you

#3 skyrydr2 ONLINE  

skyrydr2

    Tractorholic

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 5032
  • 3,408 Thanks
  • 3,158 posts
  • Location: Gardner, Massachusetts!

Posted June 03, 2015 - 07:02 PM

Check tour fuel cap vent also.
  • boyscout862 and MNGB have said thanks

#4 MNGB ONLINE  

MNGB
  • Senior Member
  • Member No: 62466
  • 994 Thanks
  • 824 posts
  • Location: Minnesota

Posted June 03, 2015 - 08:00 PM

Hi all, thanks for the replies, cap vent is good, has new fuel filter, no obstructions in fuel hose to the fuel pump, not blocked coming out of the tank either. Its been running as good as an engine can, was mowing along in fairly heavy grass when it just slows to like half throttle, haven't had time to work on it but am thinking it could be the fuel pump not supplying enough fuel at full throttle.


  • boyscout862 said thank you

#5 Genem OFFLINE  

Genem
  • Member
  • Member No: 52933
  • 65 Thanks
  • 47 posts
  • Location: nminn

Posted June 04, 2015 - 07:34 AM

When I took the fuel pump apart on my K321, I found one of the check valves had come loose. I pushed it back in place, but never figured out what holds it there other than light press fit. Still working, but I think the problem will come back someday. Gene
  • MNGB said thank you

#6 MNGB ONLINE  

MNGB
  • Senior Member
  • Member No: 62466
  • 994 Thanks
  • 824 posts
  • Location: Minnesota

Posted June 16, 2015 - 07:11 PM

Well I tried all the easier fix's, new condenser new coil new spark plug no help, so I did a differential compression test could hear air coming out of the exhaust so that means the exhaust valve is leaking. Removed the head and the breather to check valve clearances the intake was ok but the exhaust valve was at 0.009" which is much to close the manual calls for 0.017" to 0.019" so I set it at 0.018"   started to put it back together got the head reinstalled and torqued so hopefully tomorrow I get it completed and give it a test run. Makes sense now as the engine warmed up the valve would grow and the clearance would get to be even less causing the loss of power.  


  • olcowhand, KennyP and motobreeder have said thanks

#7 MNGB ONLINE  

MNGB
  • Senior Member
  • Member No: 62466
  • 994 Thanks
  • 824 posts
  • Location: Minnesota

Posted June 20, 2015 - 05:28 PM

Hi, ok after setting the valve lash got the engine back together it started and run nice so went out and gave it a try the RPM's pulled down but not like before and it didn't go way down after warming up like before so I tried adjusting the carb and discovered that now with the valves working right the carb wouldn't adjust and it was worn at the throttle shaft so I bought a new aftermarket carb off e bay it came today got it installed this afternoon and boy oh boy its like the engine had been overhauled. :dancingbanana:  It starts idles and runs good run it outside and gave it a try mowing, it preformed just like it should mowed for about .5 hr and never missed.


  • olcowhand and Cat385B have said thanks

#8 MNGB ONLINE  

MNGB
  • Senior Member
  • Member No: 62466
  • 994 Thanks
  • 824 posts
  • Location: Minnesota

Posted June 22, 2015 - 01:01 PM

Alright update #2 on the Kohler K321, went out this morning and mowed dor 30/40 minutes ran very good, so I thought I'd check out to old carb I removed for the new one. went to remove the throttle shaft it was sloppy lose, got it out and was checking to see how badly the shaft was worn and low and behold the shaft turned and the top linkage assy didn't move looked closer and it really was lose so I went to the grinder wirewheel to clean off the riveted area and discovered it had been JB welded got all the JB weld off and could see that it was so lose and worn that it would make almost a 1/2 turn. I now understand why it would act like the throttle had been pulled back when the blades were engaged or when mowing, Just for the fun of it I reassembled the throttle shaft and plate and checked I could hold the throttle plate at idle and move the shaft link to full throttle with no movement.  So I can now either replace the throttle shaft or weld it in place.






Top