cuts out at about 4600 RPM

Skyguyz · Sep 3, 2013

Dumb question.

My 1974 850 Commando runs great until about 4600-4800 RPM and then cuts out. Is that the upper end of the 850???

Thanks in advance,

Sky

Nortiboy · Sep 3, 2013

You mean it runs out power or the motor starts missing ?
Stock 850 will pull hard up to about 5500. Pointless going over 6000.

pete.v · Sep 3, 2013

Skyguyz said:
Dumb question.

My 1974 850 Commando runs great until about 4600-4800 RPM and then cuts out. Is that the upper end of the 850???

Thanks in advance,

Sky

Without think too hard (as if) and without covering the gamut of ideas, my initial response is,

Is that during WOT or just rolling up to it?
If WOT, adjust the main jet. Could go either way.
If just rolling up to it, adjust needle. Could go either way.

Rohan · Sep 3, 2013

Checked your fuel flow out of the tank is adequate ?
And the little screen/filter into the carbies is not blocked ?
Main jet(s) in the carb blocked, or almost so ?

Battery voltage good ?

Points, or Electronic ignition (EI).
The pickup wires on Boyers are renowned for breaking (inside the plastic insulation) and the vibration may cause them to not make contact above say, 4600 rpm.

Torontonian · Sep 3, 2013

C'mon, you know 828's go higher.

CanukNortonNut · Sep 3, 2013

It may be a dropped needle? Are you running Amals?
CNN

Skyguyz · Sep 9, 2013

It was simply a matter of the right carb running rich. Such a simpleton I am....

Thanks for all the help.

Sky,

(*At Red Rock canyon the other day....Such a cool photo!)

cuts out at about 4600 RPM

Skyguyz

Nortiboy

pete.v

Rohan

Torontonian

CanukNortonNut

Skyguyz

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