154 won't start

Sat Oct 02, 2010 12:50 pm

It turns over however it won't start:
-checked for spark OK
-ran it on full choke - spark plugs and cylinder were bone dry
-gas leaked from carb after trying to start
-removed plug located in intake manifold above carb and it was wet with gas-I turned it over and could see gas coming from carb into manifold.

I would appreciate any ideas.

Regards,
Steve Daly

Re: 154 won't start

Sat Oct 02, 2010 7:55 pm

I read your previous posts. What is the history of the 154?

Have you checked the ignition timing? And firing order?

Have you had the 154 running? And if so what have you done to it since?

Compression test, dry then wet?

Sounds like you have fuel and spark. That leaves compression and ignition timing.

Re: 154 won't start

Sun Oct 03, 2010 8:42 am

Hi Eugene,
My 154 was running about 6 weeks prior-nothing was done to it since.

Should the plugs be wet with fuel(they are not) if it is getting fuel?

How do I check for compression and ignition timing?

Steve

Re: 154 won't start

Sun Oct 03, 2010 12:15 pm

Should the plugs be wet with fuel(they are not) if it is getting fuel?
No, not necessarily.
How do I check for compression and ignition timing?
Compression check. Simple check is to remove the sparkplugs, one at a time, and with your finger in the spark plug hole crank over the engine. You should feel the pressure when the piston comes up on the compression stroke.

Ignition timing. Click on manuals above and select one of the later dated Cubs. Inside the operators manual is a section on the distributor and timing the engine. The 154 engine is the same and the ignition system is the same.

If you have removed any of the spark plug wires, using the manual check to see that the plug wires are on the correct spark plug.

My first comment when anyone has an engine problem is to conduct a complete engine tune up including compression test, valve tappets, etc.. A complete tune up will usually locate and eliminate most engine operation problems.

Re: 154 won't start

Sun Oct 03, 2010 1:01 pm

Thanks for the help.
I will keep you posted.

Re: 154 won't start

Mon Oct 04, 2010 7:19 am

You may also want to spray a little starting fluid into the carb, if it starts then keep looking at the carb.

Re: 154 won't start

Mon Oct 04, 2010 11:35 am

Stale gas or fresh gas????

Make sure the choke is fully closing when its choked.

Make sure the throttle is in the idle position.

If you have spark then crank it. Some are harder to start when they sit. The more i run then the better then run. I notice all of a sudden it will come to life when cranking it.

Re: 154 won't start

Thu Oct 21, 2010 3:27 pm

I changed out the rotor and it fired right up. I will take your advise and do a full tune up.
Thanks for all you help.
Steve

Re: 154 won't start

Sat Oct 23, 2010 9:30 am

sdaly wrote:I changed out the rotor and it fired right up. I will take your advise and do a full tune up.
Thanks for all you help.
Steve


Look for a burn thur mark on the inside of the rotor. It will be a black dust type mark. I've seen this on cars/trucks years ago with point ignitions. The spark goes into the distributor cap but never makes it to the sparkplug wires. I won a dianogstic challange on this question too many years ago when i was in my early teens. This was a time when mechanics were guru's and didn't have an analizer to tell them whats wrong with the ignition system.