Going back to Getting 1200 Started!

[riflemann]

Last year I started a thread to solicit help on getting a couple of my 1200 Quiet lines up and running again. I gave up.

It's warming up now in my area and I worked on one for 4 hrs today. Still cant get it started.

I replaced spark plug. Motorcraft. Cleaned points. pulled carb, some disassembly, cleaned re installed. All new fresh gas. All I got was turn, turn and a couple of single pops. Pulled a carb off another 1200, installed it, almost the same results. Tested spark with a Lisle Spark test tool, got consistent orange flashes. I was stumped.

I put and 3rd carb on. Got a series of pop, pop, pop, pop, pop, pop.....then nothing. Started 1/4 turns on the main jet screw on top of carb, then all I got was no pops but a super LOUD bang! backfire. After the 3rd try and getting big backfire, I peed on the campfire and headed home.

Anyone have any ideas, suggestions? I was going back in the morning and gonna buy a new condenser.

Thank you for ALL replies!

[mrfred54]

Backfiring thru the intake or exhaust? Valves hanging up, not seating tight. Timing?

[cadetpwr]

Sounds like inconsistant spark/timing issue. I would replace said points, and condenser. Get one of the inline light up spark checker lights from Harbor freight so you can leave it on while it runs(once it runs). Double check the gap on the points against book spec with feeler gauge or the thickness of a common business card/match book cover(old mechanics trick). Bad points and failing condenser will cause irratic spark. You can read the Kohler shop manual for this engine on their website for free. You need to set everything to book spec then try. That goes for both carb jet adjustments, point gap, a good Champion plug correct for that engine. Once she is running you fine tune the carb jets by ear. The big one that sticks straight up is the high speed jet. The one at an angle on the side of the carb(if it has one) is the low speed(idle) jet. You want the throttle about half throttle while trying to start it, to low and it will fight you, to high and it may flood. While your at the store, get a can of starting fluid and have the air cleaner cover off. Then you can use that instead of the choke to light her off and keep her going if the carb is acting wonky. If I was closer, I would help out in person. One other thing, make sure someone has not put a coil on it that does not have a resistor in it. Highly imporant. Cubs require the coil to have an internal resistor.

[Billy-O]

Refer to the following link for carburetor adjustments:

https://www.onlycubcadets.net/forum/...ad.php?t=58326

I'm not sure where you have your carburetors set, but it almost seems you have it set them all too lean which is often the cause of backfire. You mentioned you "started 1/4 turns" which is way too lean if I follow your description properly. Follow the table provided within for initial settings and hopefully you'll get your 1200 started.

[riflemann]

I swapped out the ig coil with another one off one of the four cubs i have in my barn. 2 are 1200, 2 are 1000. The old coil was cracked and leaking oil. I think I got it connected correctly, but I used the same condenser.

It backfired LOUD out of the exhaust.

Seems as if the carb swapping really didn't make a difference. But I was getting spark in my tester, but it was orange and not white.

Thanks for ALL replies!

[ironman]

Originally Posted by mrfred54

Backfiring thru the intake or exhaust? Valves hanging up, not seating tight. Timing?

I second the emotion on valve issues.

[riflemann]

I don't believe its a valve issue as the Cub was running fine till is sat for a almost a year and I went to restart it. I first found the ignition coil was cracked and leaking oil, so a traded one off another Cub.

Could I have the coil wrong when I installed it?

Could have a bad coil damaged the condenser?

Cadetpwr, I think your post has my solution somewhere in it....

[ironman]

Originally Posted by riflemann

I don't believe its a valve issue as the Cub was running fine till is sat for a almost a year and I went to restart it. I first found the ignition coil was cracked and leaking oil, so a traded one off another Cub.

Could I have the coil wrong when I installed it?

Could have a bad coil damaged the condenser?

Cadetpwr, I think your post has my solution somewhere in it....

When sitting sitting for a lengthy amount of time, the valves can get rusted into the position they have sat in.
Depending on which valve, and the situation you can get various crazy popping or backfire conditions.

Coils are wired with the wire from the ignition switch on the (+) terminal, and the wire to the points on the (-) terminal.
The condenser wire also goes on the (-) terminal.
All the condenser is, is a capacitor across the points contacts to reduce arc across the points contacts so that arcing does not burn the contacts.

Leave the condenser disconnected if you suspect it.
If it's the problem, the engine will start and run fine. Just replace with a new one asap.

[finsruskw]

Start with the basics....
Static time the engine, never fails.

[crazycubtrio]

I have had the same issue and would recommend a new condenser. I remember several that would show spark cranking and make the engine pop but wouldn’t allow it to run. Besides the spark plug it’s the cheapest part you can throw at it too.