Intermittent spark/tach/fuel pump operation

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Old's Cool

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Jul 31, 2014
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Location
Wylie TX
Greetings all,
I have an original '85 Max with 10K miles on it, PO let it sit for 19 years. Have fully (almost) resurrected it with new manifold seals, carb kits and boots, vacuum diaphragms, fuel lines, OEM spec tires, SS brake and clutch lines, etc, etc, etc.
Nagging issue arose shortly after the launch celebration, on starting the tach does not always operate, it sits at zero rpm. If allowed to continue like this it stalls for lack of fuel.
I see the tach and fuel pump are triggered off the front coil signals. I have measured the coils and pick up coils several times and always get good readings. (found the service manual error on PU coil testing) I have pulled cleaned and reinstalled the plug wires with perhaps some short term improvement but the issue persists.
Been seeing a LOT of talk about bad wires, COP upgrades and such, are my bikes symptoms in line with coil wire issues?
All the best,
D:ummm:
 
Just for the heck of it....pull your fuses, clean the contact points and apply some di-grease. I forget which fuse it is but there is one that controls the neutral light, signals, fuel pump & tach.... but do them all, including the main 30A one and see what happens.

AND....Welcome to the forum O/C
 
Is this also one of the black wire (grounds) that all attach under one bolt to the frame, just outside the battery box on the right side? If so, make sure all those wires connect to ground properly.
 
Thanks guys -
I've been through the harness to coil connectors several times, made sure they're clean, and added some dielectric grease too.
Removed and Checked all fuses, clean and tight.
Removed ground wires, cleaned and reinstalled tight.
Bike started on two cylinders (rear) with no tach or fuel pump operation while running, revved up and fronts kicked in with tach and fuel pump too.
???
 
I can always send you out an electrical loaner kit. Might have a bad CDI box. Just have to email me. You'd only pay shipping and any part you wanted to keep that fixed the issue.

Sean
 
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