123 starting problems

bsb369 · #1 02-18-2012, 11:17 PM

OK, I'm gonna do my best at trying to describe the problem I'm having. Forgive me if I'm not too clear. When I try and start my 123 it will fire almost backfire but will not run if I move the throttle to the slow position it will eventually start after stalling several times. I've reset the points in different settings from .020 to .015 with no difference seems to work best at .017. The engine has been rebuilt at some point because the piston has a .008 stamped on it. Just wondering if this could be a valve clearance problem between the lifter and the valve. Any advice is appreciated.

Bad Brad · #2 02-19-2012, 08:03 AM

I also have a 123 great little machines, to me ( and I am no expert) it sounds like the carb needs to be adjusted. Set it as recommend in the manual and then adjust it from there.

Ridgerunner97 · #3 02-19-2012, 08:45 AM

I'm currently fighting with my 123. I put new points and condenser in it, set the carb to factory specs and it still was running lean. Found out that the push rod that actuates the points was made of aluminum and then switched to steel at some point. If yours has a few hours it could be worn and a few thousandths matter trust me! I'd try to get a new steel pushrod, install it and then go from there. If the timing is correct etc. (you can check em with a timing light throught the blower housing) I would then pull the head and check the valves. I'm doing my valves and I'll finally be done with it and ready for spring.

bsb369 · #4 02-19-2012, 11:29 AM

I tried resetting the carb back to factory settings with no difference this is the second carburator I've tried just to make sure. I'm seriously considering just pulling the engine and going through it to since I don't know who, when or how it was rebuilt, just to make sure everything is correct.

cmatthew · #5 02-19-2012, 12:47 PM

mattg posted a static timing method thats works great for those of us that dont have timing lights. check for it in the search.

_DX3_ · #6 02-19-2012, 01:17 PM

Quote:

Originally Posted by cmatthew

mattg posted a static timing method thats works great for those of us that dont have timing lights. check for it in the search.

It will be in the tractor technical library.

bsb369 · #7 02-19-2012, 01:57 PM

I've used the static timeing method on my 122 and it worked great so I tried on my 123...it started but it still wants to stall when it turns over almost backfires so I'm thinking that maybe the cam might have been installed and the timing marks not lined up or the valves may have been adjusted wrong??

_DX3_ · #8 02-19-2012, 02:09 PM

Yeah check the valve lash first.