littleblackflash Posted October 11, 2009 Report Share Posted October 11, 2009 Hi all I'm just finishing the restoration of a M91 Bultaco and I've got as far as doing the wiring. The stator plate I have has 2 gold coloured coils, points at the top and a condensor at the bottom. The problem is I have no wires. What should I have and where should they run too? Quote Link to comment Share on other sites More sharing options...
bultaco49 Posted October 11, 2009 Report Share Posted October 11, 2009 Hi - here is a wiring diagram for the Sherpa. Just follow the ingition wires and ignore the lighting. Ignition is same with or without lights. Many people move the capacitor from the stator plate to under the fuel tank for ease of access. Scrape paint from all earth connections and check with meter. On the stator plate itself the wiring should be- from the flywheel magneto base plate there should be a green, black, red and yellow wires. Connect yellow to number 1 on the connector block, red to 2, black to 3 and green to 4. From 3 on connector block a black wire should run to HT coil live. From 4 on connector block a white wire should run and be earthed by a HT coil retaning screw. If you want to connect a cut out switch run a wire to live (unearthed) side of switch from number 3 on connector block. When depressed the cutout should earth this connection. If wires from magneto have been changed black wire should connect to terminal on points (along with condensor). Green to tightly wound coil on stator plate (next to condensor) red to other end of this coil. Yellow connects to other coil on base plate. The most important wire not to be snagged to earth is the black wire from points to connector block and on to coil. Hope this helps 1 Quote Link to comment Share on other sites More sharing options...
littleblackflash Posted October 12, 2009 Author Report Share Posted October 12, 2009 Many thanks, that's great. My Bultaco is a barn find under going a nut and bolt restoration (like many) and I have a bit of house hold flex going into the back of the stator plate. Is it important to get the Green and Red wires connected to the tight coil the correct way round? And how can I tell if it is the right way round? My Right coil (loosly wound) is not conected to anything which seams to be correct (yellow wire). Was this used for the horn? I'm mising from my box of parts, the connector block. Is it just a white choc-blok electrical connection or something special? Final question of many, What should the points gap be set too? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
pedronicman Posted October 13, 2009 Report Share Posted October 13, 2009 The CORRECT wiring for Sherpa's- Originally there should have been 4 wires as follows- You should have 3 wires coming from the L/T coil (nearest to front of bike)- Black- from L/T coil to points and then to HT coil condensor also branches off this Green goes to EARTH only on stator or originally to frame Red is for HORN ONLY - if not used then cut/blank off The other R/H coil with a yellow wire is for lights ONLY this can be blanked off or coil taken off completely it seems the last post is very confusing!!!! Quote Link to comment Share on other sites More sharing options...
bultaco49 Posted October 13, 2009 Report Share Posted October 13, 2009 Sorry black flash - What I should have said was, why not buy a Bultaco Sherpa workshop service manual from Bultaco UK which has the correct wiring diagrams for Sherpa with or without lights, horn ect. If you follow them carefully you will have a perfectly running Sherpa, just like mine. Best of luck with your restoration. Quote Link to comment Share on other sites More sharing options...
littleblackflash Posted October 13, 2009 Author Report Share Posted October 13, 2009 Sorry black flash - What I should have said was, why not buy a Bultaco Sherpa workshop service manual from Bultaco UK which has the correct wiring diagrams for Sherpa with or without lights, horn ect. If you follow them carefully you will have a perfectly running Sherpa, just like mine.Best of luck with your restoration. That could be the solution. I was trying to see if I could get it running just to test the engine rebuild. I'm thinking now, the best thing to do is call Dave Renham and buy an electronic ignition. Thanks for all the help. Quote Link to comment Share on other sites More sharing options...
pastman Posted October 28, 2023 Report Share Posted October 28, 2023 Hi there guys I'm trying to sort out the electrics from my Sherpa 350 I rewired the stator but I'm not sure if it's right Can anyone tell me the colors from the ignition coil Quote Link to comment Share on other sites More sharing options...
lorenzo Posted October 29, 2023 Report Share Posted October 29, 2023 14 hours ago, pastman said: Can anyone tell me the colors from the ignition coil As stated by Pedronicman above : black to points & condenser, green to earth. Get rid of the mains flex. - it's just confusing the issue..... Quote Link to comment Share on other sites More sharing options...
pastman Posted October 29, 2023 Report Share Posted October 29, 2023 22 minutes ago, lorenzo said: As stated by Pedronicman above : black to points & condenser, green to earth. Get rid of the mains flex. - it's just confusing the issue..... Lorenzo I want you to look at the picture above and then tell me the colors to that coil please Quote Link to comment Share on other sites More sharing options...
pastman Posted October 29, 2023 Report Share Posted October 29, 2023 Just now, pastman said: Lorenzo I want you to look at the picture above and then tell me the colors to that coil please The colors you see I put them there. But I'm not sure which one is which now Quote Link to comment Share on other sites More sharing options...
lemur Posted October 29, 2023 Report Share Posted October 29, 2023 We see one coil so this must be for ignition, that (single phase) coil should have a measurable resistance of one or two ohms. The photo doesn't really show where the solid white and the green/yellow wires go, so the white wire that is spliced into the blue wire plus the brown wire appear to be the AC output from the coil. Do an ohm meter test between the blue and brown wires, if you see one or two ohms resistance across those two wires that is the coil winding you are measuring. Quote Link to comment Share on other sites More sharing options...
pastman Posted October 29, 2023 Report Share Posted October 29, 2023 42 minutes ago, lemur said: We see one coil so this must be for ignition, that (single phase) coil should have a measurable resistance of one or two ohms. The photo doesn't really show where the solid white and the green/yellow wires go, so the white wire that is spliced into the blue wire plus the brown wire appear to be the AC output from the coil. Do an ohm meter test between the blue and brown wires, if you see one or two ohms resistance across those two wires that is the coil winding you are measuring. I did take measurements but I'm not sure whether the brown or blue should go to the points. The white seems to be the ground (green) But I'm neither sure of anything If anyone got an original unmolested coil then we'll find out for sure 😁 But thanks everyone for the help Quote Link to comment Share on other sites More sharing options...
lemur Posted October 29, 2023 Report Share Posted October 29, 2023 (edited) The most basic wiring diagram that is similar to what you have right in front of you is a chainsaw. Wire it just like a chainsaw. search 'chainsaw points wiring diagram' the first images that show will work. Edited October 29, 2023 by lemur clarity Quote Link to comment Share on other sites More sharing options...
lemur Posted October 29, 2023 Report Share Posted October 29, 2023 How many wires are physically connected to the coil, we can't tell if the one white wire goes to the coil or just under it, if you have 3 wires exiting the coil that is potentially a combined lighting and ignition coil, only two wires would be just an ignition coil. Lighting coil will have measurable resistance separate from the ignition coil and one wire common to both those. Quote Link to comment Share on other sites More sharing options...
pastman Posted October 29, 2023 Report Share Posted October 29, 2023 6 minutes ago, lemur said: How many wires are physically connected to the coil, we can't tell if the one white wire goes to the coil or just under it, if you have 3 wires exiting the coil that is potentially a combined lighting and ignition coil, only two wires would be just an ignition coil. Lighting coil will have measurable resistance separate from the ignition coil and one wire common to both those. You're right Three wires are coming of the coil 2 are for the ignition and one for the horn The two for the ignition I'm not sure which one goes to the points Quote Link to comment Share on other sites More sharing options...
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