Stormin 9,985 #1 Posted March 8, 2022 (edited) My C-125 and C-121, (The Black Horse), had not been run since before Christmas. Yesterday I decided to run them. I'll be needing the C-125 for mowing duty soon. The C-125 has been a bit of a beggar to start for a while. Taking some time cranking before it would fire up. It would be trying but just chuffing and not firing properly. Had a good spark and fuel getting through. So I checked the points and reset them. That is a pain to do. As soon as the securing screw was tightened, the gap would open a touch. Using a 20thou feeler and a 19thou one, I got the gap so the 19 would just slide in and the 20 a tad tight. Starting was no different so I decided to change the carb. I had a reconditioned one on the shelf so fitted that. Starting was much better and I let it warm up and adjusted the carb. Switched it off and restarted a few times and all is improved. I'll see what it's like later afternoon with a cold engine. Fingers crossed. The Black Horse just refused even to try to start. Which was a bit of a surprise because it normally a first time starter. No spark at the plug. I tried two. Checked and reset the points. Same method as the C-125. I have a spark tester that you fit between the HT lead and plug. Fitted that a discovered an intermittent spark. Checking the wiring, I found the connection of the negative wire from the coil, at the points, was slightly loose. Tightened that and the tractor started immediately as normal. Edited March 8, 2022 by Stormin 11 3 Share this post Link to post Share on other sites
SylvanLakeWH 28,533 #2 Posted March 8, 2022 (edited) Just a thought… I use a marine style primer bulb on my C 105 and it makes a big difference starting cold. Couple squeezes and she starts right up… Edited March 8, 2022 by SylvanLakeWH 7 2 Share this post Link to post Share on other sites
kpinnc 14,663 #3 Posted March 8, 2022 16 minutes ago, SylvanLakeWH said: Just a thought… I use a marine style primer bulb on my C 105 and it makes a big difference starting cold. Couple squeezes and add she starts right up… I've been impressed at the difference these make for tractors with under-seat fuel tanks. I am definitely a believer! 5 Share this post Link to post Share on other sites
Stormin 9,985 #4 Posted March 8, 2022 (edited) They both have primer bulbs. Fuel delivery was not the problem as previously stated. The C-125 still played up this afternoon. One thing I'd been wondering about was the valve clearances. So they got checked this afternoon. Inlet was OK but the exhaust was a bit tight. Reset that to 18thou. While replacing the carb' I checked to see if the throttle butterfly valve was closing fully. It wasn't. So the governor to carb rod was adjusted. Hopefully those two things will have improved things. Ran out of time so I'll see how things go tomorrow. Edited March 8, 2022 by Stormin 4 1 Share this post Link to post Share on other sites
ebinmaine 72,932 #5 Posted March 8, 2022 Nice work Sir. Keep us posted... 1 Share this post Link to post Share on other sites
