Technical Starter Not Engaging

[toscy82]

Hi Guys,

I think I may already know the answer to this, but I'm having some intermittent issues with my starter (126 swap).

Essentially it seems to pick and choose when it wants to engage the flywheel. Sometimes it just spins without engaging, other times it works perfectly.

I've been looking at threads and they suggested to check the wiring, which I did and everything seems fine visually. That said, I haven't hooked up a multi-meter and am unsure of what I should be seeing for power, switch, and ground read outs (any help here would be appreciated).

The other thing I've seen suggested is to swap out the brushes and solenoid. I inspected, cleaned and greased everything in the starter after dismantling about a year ago, so I think the brushes should be okay (they had plenty of meat on them at the time) and I doubt they would be impacting the engaging mechanism anyway. Has anyone had a solenoid that just decided to work only half the time?

As always, any insights are appreciated, thank you!

 

[the hobbler]

Would I be correct in thinking that you have a 126 engine in the back of your 500? If so, has a 500 flywheel been fitted? If a 500 flywheel HAS been fitted I am not surprised that you have this problem; where the starter occasionally just spins and does not engage. The 500 flywheel is often fitted to the 126 engine because it is 2 kg lighter, BUT it sits closer to the back of the engine, (and therefore further from the starter)--it is something I learned to live with on my tuned 652cc '126' engine. One of my 'over-the-winter' jobs has been to change the flywheel back to a lightened 126 flywheel.

 

[toscy82]

Yes you are correct, I'm running a 650cc 126 motor and trans. I don't believe the flywheel has been switched out, but if there is an easy way to check I can take a quick look.

Would that cause the starter to only engage roughly half the time? I figured the intermittent issue would be more an electrical/solenoid thing than a mechanical one.

 

[the hobbler]

When you have the flywheel off, weigh it and let us know what the weight is please. The 500 flywheel lies quite close to the back of the crankcase---the 126 has more clearance and therefore sits close to the starter bendix. If the starter is spinning, but not engaging with the ring-gear, than the fault is unlikely to be electrical. I would suggest that you obtain a genuine '126' flywheel (which will weigh about 7.3kg) and have the back of it skimmed (as well as the friction surface skimmed to ensure flatness). The minimum weight that I would recommend for road use is 4.5kg. The standard 500 flywheel weighs 5.3/5.4kg