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Stumped By My Sherpa.


netley
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Doesn't the V on the bp5ev spark plug just mean a v'ed out electrode

No, but I can understand where you're coming from. The EV, HV, EGV, etc, have a Gold Palladian central electrode with a flat firing surface.

Whereas a BP5EY would have a v groove on the firing surface end of the central electrode. As a marketing tool NGK decided to put the slogan "V Power" on the outside of the boxes that the EY plug were packaged in, just confuse matters.

Edited by model80
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I still would prefere just standard plugs, the expensive ones doesn't work better for two strokes in my personal experience, the super expensive plugs for racing are out of financel reach and the other high tech plugs are made through the demand of the car industry because the sdervice intervalls has been doubeld at least. Thus plugs with longer durability where needed which doesn't mean they work better!

 

If you don't have a bright blue spark whioch do even makes a noticeable noise on a standard Bultaco magnet and point's ignition you have an ignition issue.

 

If there is a blue spark than as Nigel Dabster already mentioned the carb or his surroundings are the problem,

 

 

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Hi, Rain stopped so time to play. Just checking, Does everything look ok in this pic of the coil wiring.

Going to check the timing hasn't moved since I set it first. 

It's been stood for quite a while and then used quite a bit of a week so I suppose it's possible the mains or the seals have given up. Is there a way to check this?

Thanks for looking.

Neil

post-21331-0-26065300-1471602731_thumb.jpg

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Timing had slipped. Why they don't put some timing marks on the flywheel I don't know. Put some tape on flywheel and crankcase and then used a cigarette paper to get the right opening point.

Fired easily and ran until warm and ticked over. I stopped it and tried again and all well.

I will see how things progress as there will be trouble with the seals at some point I'm sure.

Thanks for all the advice.

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"Why they don't put some timing marks on the flywheel I don't know."
 
I made my own permanent timing markings on the flywheel. One at TDC and one at 2,6mm before TDC.
These correspond with the marking on the small aluminium piece I mounted in the top right of the flywheel casing.
 
Easy peasy.

 

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post-15723-0-56964600-1471616275_thumb.jpg

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Neil, as I see by your photos , no auto condenser under the tank as we discussed, I take it you have a new Femsa mess!!

 

Please do the electrics as we discussed.

 

Please don't sweat the seals.

 

Have a nice day.

 

Larry

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Hi Netley,

 

On the pic on post22 above, I would suggest you take the green lead coming up from the flywheel and put it into a connector direct to fit under the screw clamp, instead of the white wire as you have done, then take out that bolt through the mounting plate and scrape the paint off the frame itself (on the other side, under the head of the bolt not under the nut) That way you get a direct connection to the grounded side of the coil, whereas you are relying on the quality of the connection to the coil mounting plate which may not be really electrically connected to the frame.

 

Equally I would always solder wires in connecting spade or circular lugs and not just rely on clamping them because the vibration and chemical reactions always have the potential to create corrosion over time.

 

Just to help further I am including one of the photographs from our feature on improving ignition systems in our digital magazine, ORRe. It shows the way Sammy Miller modified his ignition on his own Sherpa in 1967. As you can see he fitted a spare ignition coil complete with plug lead and plug cap already wired in and tucked up under the tank. But note that his ground to frame connection is quite separately made direct to the Sherpa frame, the ground connector spade closest to the steering head.  When I visited Sam in his workshop and we talked about various topics, Sam agreed that he also always soldered spade terminal connections, never relied just on crimped ones.

 

 

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Edited by laird387
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The green is the ground or earth connection from the generator in the flywheel, on your photograph it is connected to the white wire which you can't see because it's behind the connector. It is the green lead that needs to be connected directly to the Sherpa frame.

 

I don't know exactly which year etc. your Sherpa is but I suspect the red and yellow wires are from the lighting coil, but you need a real Sherpa expert for that, I'm just a retired electronics engineer.

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