'78 Moby V50, stall issue.

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'78 Moby V50, stall issue.

Greg Bowl /

macleod

Jul 30, 2020 01:17PM

I've replaced the condenser (externally), she starts better, restarts better when hot also.

NOW my issue is, she runs great for a few miles, fully warmed, then can die. Won't restart until seemingly cooled down.

Thinking coil, gets hot and faulty?

Just got a 6v/12v spark tester, if I can get her to stall again maybe I can verify spark quickly.

I'll take the carb apart again anyway, but I'm not expecting a fuel issue.

Original 42 year old coil, 575 original miles,

No visual signs of degrading on the coil or wire.

I did not open the magneto to replace the condenser for obvious reasons, but, can the old condenser which is still in the circuit cause trouble? Didn't see anything about that when investigating the condenser replacement part.

ANY help appreciated!

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Re: '78 Moby V50, stall issue.

Stephen Keller /

keller_stephen

Jul 30, 2020 02:02PM

I think you have to at least cut the wire to the old condenser when you replace it. When removing the flywheel remember the nut is reverse threaded. If the coil is bad will be chalky looking and perhaps show some cracks. Check that your ground strap is secure. Very cool rear rack, but what in the world is going on with that seat? You must be really tall! :) (edited)

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Re: '78 Moby V50, stall issue.

Mike Boyd /

Go to branch

boyd

Jul 30, 2020 02:40PM

I wouldn't rule out a fuel starvation issue (gas cap not venting, petcock not flowing fast enough, obstruction preventing fuel from filling the float bowl fast enough) or even a dragging starter clutch shoe potentially if it's dying at idle specifically.

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Re: '78 Moby V50, stall issue.

P D /

pdcomm

Jul 30, 2020 02:50PM

When is the last time you replaced anything and did not remove the 'replaced' piece ?

Of course , remove the old condenser .

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Re: '78 Moby V50, stall issue.

Greg Bowl /

macleod

Jul 30, 2020 03:27PM

This is the rare "XL" model.

Actually, I had some 1" SS pipe so I lifted the seat a few inches, I'm 6'1".

The external condenser rework was recommended by guys on this site instead of taking the flywheel off, and likely my condenser is behind the magneto plate.

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Re: '78 Moby V50, stall issue.

Greg Bowl /

macleod

Jul 30, 2020 03:32PM

It stalled at running speed not an ideal issue. You have me thinking about fuel starvation, but I'd think it would at least restart fairly soon after, but I'll check it.

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