snowhound 105 #1 Posted June 24, 2021 My 414-8 with a magnum 14 is surging at high RPMs and when under a load I was going to adjust the carb but there isn't a high speed adjustment, is this factory? I don't know the year of the tractor the tag isn't readable. Snowhound Share this post Link to post Share on other sites
oldlineman 1,495 #2 Posted June 24, 2021 Give it a drink of SeaFoam and some time works. Bob 2 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,246 #3 Posted June 24, 2021 Post all the numbers off the engine ID decal including the serial number. Sometimes we can determine the tractor model number from them. Garry Share this post Link to post Share on other sites
pfrederi 18,334 #4 Posted June 25, 2021 Many magnums came with Walbro Fixed main jet carbs (Pollution control???) Cleaning is about the only answer. Also check for play in the throttle butterfly shaft... Share this post Link to post Share on other sites
peter lena 9,092 #5 Posted June 25, 2021 @snowhound how is your gas tank vent ? possible fuel starvation ? dirty fuel filter ? pull that jet and sea foam , extension small tube spray it down , reinstall jet , start up use your hand over carb at speed to help suck thru seafoam effect thru it , as it comes back up to speed spray it down again , just a fix that has worked for me , pete 2 Share this post Link to post Share on other sites
Zeek 2,286 #6 Posted June 25, 2021 (edited) I agree with the others, you have a fuel delivery issue somewhere. I just went through the exact same issue with a 26 HP Kohler Courage. After three carb cleanings and the same issue, I threw the carb in the trash and got a new one on on Amazon for $30 with fuel solenoid and all. Threw it on with no adjustments and it purrs like a kitten now My days of wasting hours trying fix a disposable part are over unless it's a model you are trying to keep original. I believe you can get new carb for your engine on Amazon for $22. Edited June 25, 2021 by Zeek 1 Share this post Link to post Share on other sites
peter lena 9,092 #7 Posted June 26, 2021 @Zeek, agree with the rop shop on amazon , price is right , quick swap , picked up quite a few items from them , with no problems . looks like a simple fix to me , pete Share this post Link to post Share on other sites
