General Difficult hot starting Uno 70

[alexGS]

Hi, this is a familiar topic and I don't expect anyone will come up with a new answer but ya never know

Friend has Uno 70 (1301cc engine). When engine is hot (new thermostat, so I mean about 95 degrees) and switched off (or stalled), it is difficult to restart. Engine cranks very slowly until you pump the accelerator a few times - then it turns over faster and starts normally. (Opposite problem to most hot-start cases where the engine floods!)

Those of you with performance-tuned engines may recognise this as over-advanced ignition. The engine is firing against itself (giving the slow cranking). Naturally, the timing was spot-on at 10 degrees BTDC. However I have retarded the timing to 5 degrees - noticeable improvement but problem persists with engine really hot.

I'm about to strip the starter motor (again - has already had new brushes) to see if I can get it to crank the engine over just a little faster so that the engine fires with, rather than against, itself.

What else can we do? I don't want to retard the timing any further as that will hurt performance.

Thanks for reading,
-Alex

 

[Jemmy]

Hi Alexgs...
I do had same problem with U. The problem is the starter motor an it electrical wiring and grounding. Thats is not the timing advance problem.I do this :
1. I strip down Starter M, and change the As bearing with a new one, clean the housing and all parts in / at starter motor. Put a little grease at the As and bearing at front(gear side) and rear(brush side), don't too much
2. Check the + cable (red & big one) from batt to starter M for corossion or dirt or Loose.
3. If all of thats ok, but it still hard to crank on hot engine, I would try to change the starter Motor complete with a new one.
I did step 1- 2, and the problem solve, hope work with you too....
ehm..... sorry for my english... OK