rplant Posted May 31, 2007 Report Share Posted May 31, 2007 I'm trying to get the ignition to work on a M91 SherpaT and I don't get any spark, so I want to make sure I have the wiring right. Does anyone know or have the correct wiring diagram for the Sherpa T with the Femsa points ignitions? Quote Link to comment Share on other sites More sharing options...
bultaco49 Posted May 31, 2007 Report Share Posted May 31, 2007 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. Easier still is to fit an electronic system available with diagram and easy timing instuctions from Bultaco uk. Tim Quote Link to comment Share on other sites More sharing options...
jesusg9 Posted May 31, 2007 Report Share Posted May 31, 2007 Hi, hope this helps , Quote Link to comment Share on other sites More sharing options...
greeves Posted May 31, 2007 Report Share Posted May 31, 2007 IMPORTANT: Make shure that when you put the coil in the frame ("Bobina de alta" in that diagram) there is no paint at all in that part of the frame in between the contact of the coil and the frame, as many times in Bultaco Quote Link to comment Share on other sites More sharing options...
rcgods Posted May 31, 2007 Report Share Posted May 31, 2007 Greeves is totally correct here have had to scrape powercoat and paint back to bare metal to get a spark from mine. On my bike it also didn't help the bike had been on fire so all the wiring was burnt out and had been replaced with household mains cables so none of the the colours matched and had to strip the ignition down to complete re-wire Quote Link to comment Share on other sites More sharing options...
greeves Posted May 31, 2007 Report Share Posted May 31, 2007 That aluminium tamk is a beauty, I would love to have one Quote Link to comment Share on other sites More sharing options...
rcgods Posted June 2, 2007 Report Share Posted June 2, 2007 That aluminium tamk is a beauty, I would love to have one Quote Link to comment Share on other sites More sharing options...
rplant Posted June 3, 2007 Author Report Share Posted June 3, 2007 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. Easier still is to fit an electronic system available with diagram and easy timing instuctions from Bultaco uk. Tim Tim, thanks and thanks to everyone else as well... After I hooked the black to black and grounded the green (had to scrape off paint as suggested), replaced the condenser and points, set the points, bike fired up on first kick... not kidding, it's been sitting for 10 years according to the guy I bought it from... I pretty much rebuilt the whole bike except for splitting the crankcase, and I was very happy to get it started so quickly... So again... Thanks to everyone for their comments and for the pic... While I was not born there, I grew up in Guatemala so I could very much read the wiring in Spanish... Quote Link to comment Share on other sites More sharing options...
kawahonkabsa Posted June 4, 2007 Report Share Posted June 4, 2007 I too am having problems Only done 2 trials and broke down in both with ignition problems. I have identfied all the wires on my stator except there is a fine copper wire (light brown sleeving)from the tight wound coil to the black wire connected to the points and harness , not the condenser wire. so there are three wires connecting to the points. Is this correct? I could not get a spark wiring to the circuit diagram but my coil earth may be dodgy. Anybody know the recommended resistances of the various coils. mine are 3.8 ohm green to single copper and hence black. 1.9 ohm red to soldered earth 1.6 ohm yellow to earth HT coil 2.5 ohm and 3000ohm spark plug lead. I will try the previously mentioned wiring tonight. Mick Quote Link to comment Share on other sites More sharing options...
cmguk22 Posted July 15, 2007 Report Share Posted July 15, 2007 Hello Everyone. I have the same/similar problem on a Model 92 Bultaco Sherpa T 350. No spark at the plug, I initially thought the points. So I went the whole hog and also brought fresh HT coil, Spark plug and condenser Quote Link to comment Share on other sites More sharing options...
swooshdave Posted July 29, 2007 Report Share Posted July 29, 2007 Hello Everyone.I have the same/similar problem on a Model 92 Bultaco Sherpa T 350. No spark at the plug, I initially thought the points. So I went the whole hog and also brought fresh HT coil, Spark plug and condenser Quote Link to comment Share on other sites More sharing options...
kawahonkabsa Posted August 1, 2007 Report Share Posted August 1, 2007 Hello Everyone.I have the same/similar problem on a Model 92 Bultaco Sherpa T 350. No spark at the plug, I initially thought the points. So I went the whole hog and also brought fresh HT coil, Spark plug and condenser Quote Link to comment Share on other sites More sharing options...
kawahonkabsa Posted August 2, 2007 Report Share Posted August 2, 2007 Hello Everyone.I have the same/similar problem on a Model 92 Bultaco Sherpa T 350. No spark at the plug, I initially thought the points. So I went the whole hog and also brought fresh HT coil, Spark plug and condenser Quote Link to comment Share on other sites More sharing options...
kawahonkabsa Posted August 2, 2007 Report Share Posted August 2, 2007 Hello Everyone.I have the same/similar problem on a Model 92 Bultaco Sherpa T 350. No spark at the plug, I initially thought the points. So I went the whole hog and also brought fresh HT coil, Spark plug and condenser Quote Link to comment Share on other sites More sharing options...
peterb Posted August 11, 2007 Report Share Posted August 11, 2007 Just thought I'd add my thoughts to this, On my 325 Bultaco, I run the black wire from the low tension coil/ign points to the HT coil, via a terminal connector. I always remove the condensor from the magneto area (it's better away from the heat and easier to get to if re-located) and mount this on the terminal block mounting bracket, making sure there is a good ground connection between the condensor and the frame, no paint. The wire from the condensor connects with the black wire from the points at the terminal block. Connect the HT coil low tension wire to this terminal. Leave the yellow and the red wires disconnected. Connect the green (earth) wire to a good ground at the HT coil - no paint. Wired my Bultaco's this way for many years, always go well. Bye, PeterB. Quote Link to comment Share on other sites More sharing options...
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