1965 m20c hardstarting cold or hot

[reuben]

Hi my dad has an M20c. at the moment it does not want to start.the mags were checked and found not faulty.there was also a healthy fire of spark. after the aircleaner was removed,cleaned and the engine started and he could continue on his journey.

unfortunately after stopping for fuel along the way it does not want to start up. anyone have any ideas as to what this could be? or how to start up?

Regards

Reuben

 

 

[Mooneymite]

Hard starting engine means one, or more of the fuel/fire/air components is not right.

The only time I had trouble with starting my O-360 was when the capacitor in my SOS (shower of sparks) went bad.  The capacitor was very cheap and we also replaced the points while we had it out.  Once replaced, the engine started in about "two blades".

However, there are lots of other things that might be out of whack.  Any other symptoms?  Did the hard starting happen all of a sudden, or has the engine been getting progressively harder to start?  Were any changes made to the engine, or fuel system?

 

 

 

 

[reuben]

Quote: Mooneymite

Hard starting engine means one, or more of the fuel/fire/air components is not right.

The only time I had trouble with starting my O-360 was when the capacitor in my SOS (shower of sparks) went bad.  The capacitor was very cheap and we also replaced the points while we had it out.  Once replaced, the engine started in about "two blades".

However, there are lots of other things that might be out of whack.  Any other symptoms?  Did the hard starting happen all of a sudden, or has the engine been getting progressively harder to start?  Were any changes made to the engine, or fuel system?

 thanks Mooneymite

the shower of sparks was tested and appeared fine.this is a problem that has become progressively worse.now its just dead.no changes made that we are aware of although the engine was completely rebuilt very recently.someone in the local industry suggested it could be the accelerator pump?

 

 

 

[Mooneymite]

If you're engine is like my O-360, the accelerator pump theory is easy to check.  Pump the throttle a few times, there will be a strong odor of gas.  Pump it more, you'll see gas dripping.  However, be very aware of the fire hazard.  Have access to an extinguisher!

Does the engine crank fast enough?  A weak battery, or a worn out starter could be part of the problem, too.

 

 

[Hank]

Based on my experiences, there are two things to check after mags & Shower of Sparks:

1)  Spark plug gaps. When were your plugs last cleaned and gapped? I just changed from every annual to every oil change due to difficult starts just before annual, a year after changing the [inexpensive] capacitor.

2)  What works for me when she is stubborn:  pull mixture about halfway back. While cranking, vigorously pump the throttle from idle to full and back. She may cough and spit, but keep cranking and pumping until she fires good, then let go of the key and QUICKLY advance mixture and pull throttle back.

Good luck with yours!

[lahso]

This happened to me one time, and found a bad cell in my battery. Replaced the battery and had normal starts - cold and hot.

[M20F]

Quote: reuben

after the aircleaner was removed,cleaned and the engine started and he could continue on his journey.

 

 

[reuben]

Thank you for all the ideas from everyone. Each one of them could very well be the possible cause of the missery suffered.Well the thing is we have removed the aircleaner and cleaned it,but problem still persisted.the carb did not seem to spurt fuel when pumped manualy so we removed this and sent it away to the engine rebuilders as this is a new carb fitted and it is still under waranty.

hopefully we will have it fitted on saturday and will let you guys know how it goes after that.

thank you again kind folks

regards

Reuben