Possible ignition issue

[andygbsmith]

Today I had another issue with the bike running on one rotor. It has happened occasionaly (6 to 8 times) over the last 5000 miles. Sometimes it only happens for a few seconds, other times as today it happens for about ten miles. Today it was a real pain as the last thing I needed was the rotor cutting in and out on snow covered roads. The day before I covered 200 miles with not issues at allI have tried all the normal things, plugs, caps, leads, fuel system etc.I have read that the ignition can fail like this (still on the original type) any ideas or ways to test it?Andy.

[johnbirchjar]

Hi Andy,I have hade simaler problems myself in the past,once was the ignition trigger switch,and once was the Boyer ignition system.(fortunatly,thousands of miles and a number of years appart.)try checking the gap on the ign:trig: switch first as it's the easiest.regards,J.B.

[Richard Negus]

Hi Andy,JB's suggestion is a valid one, but it does suggest a Boyer problem too. Did the tacho stop working at the same time ? The Boyer doesn't cope very well with surges in voltage and it may indicate a fault with the charging circuit. Check the following :-. engine running, put a voltmeter across one of the batteries ; it should read anything from 13 to 15 volts. Under 13, there's no charge; above 15.2 and the regulator is probably faulty.. by the water pump, is the 3-blade connector from generator to wiring loom burned ? If so, use a 'chocolate block' screw connector.. at the regulator, check that the loom earth tag goes to the same regulator fixing bolt as the regulator earths (2 x black-white wires). Many bikes wrongly had the loom earth to the electrics plate stud.. improbable in this weather, but the ignition unit may be overheating ; usual mod is to stick it on the front left side of the fuel tank - but don't forget to re-tighten the regulator fixing screws.R.

[johnbirchjar]

Hi guys,Richards question re; tacho,mine has just started to "stop working" over 3,000 revs,( it behaved like this previously exept that it fluctuated wildly, then it would be fine for a while then off it would go again. )then I fitted the "new improved" ignition system last summer and it had been fine until yesterday,it dos'nt flicker,just dies,then when the revs drop to below 3,000 it works again,working or not performance is not affected,any ideas?J.B.

[Richard Negus]

JB,All the ignitions, with the exception of the IP2 CDI system, switch the -ve side of the coil on and off just like contact breaker, but far more accurately with regard to timing and amount of low speed retard. This applies to the original Boyer and both digital replacements.The tacho on Classics, Commanders and F1 / F1 Sport takes a feed from a signal wire (usually from the black/yellow) ; if the tacho stops working, but the engine performs ok, then there are three possibilities :-. the feed wire from the coil to the tacho has a fault (bad contact, broken wire, etc..). the tacho has an internal fault, permanent or intermittent. the positive feed or negative ground wires to the tacho have a fault (bad contact ..... etc..)A defective Motometer (says 'Made in Germany' on the face) tacho is the usual culprit ; replace it with a Veglia ('Made in France') one from an IP2, if you can find one. They were usually 100% reliable and take a feed from one of the generator a/c wires.R.

[MrB]

I have an IP2 with Commander engine. I also have a similar intermittent tacho fault which I haven't tried too hard to trace as it rarely shows itself. Sometimes when running at very high speed to flat out the tacho needle begins to fluctuate wildly and typically ends up reading zero until speed is reduced back towards 50 or 60 mph, then magically normal operation restores itself. No problem with high engine revs in intermediate gears, only after flat out for a couple of minutes or so.Everything else works fine, no ignition faults or other electricals playing up that I know of. Used to have a Sparkrite unit but fitted one of Graham's units 3 years ago, very pleased with it. Tacho fault has always been there so thanks Richard for the tips of things to check.Johnny

[MrB]

Oh yes, forgot to say my tacho is a French Veglia unit.

[johnbirchjar]

Thanks Richard,I will check wires and things when the weather warms up a bit,(it's rather nippy in the garage at the moment,)and I'm allmost sure my tacho is of the French variety,and the new ign;system I fitted last summer was one of Grahams too,up to now it is fine. A plea to the rotary comunity at large,do's anyone have a wiring diagram for the Classic that they would'nt mind photocopying and posting/e-mailing to me?(Alan Stubs did one for me but about a third of it did'nt print and I did'nt want to bother him again,)also did Nortons ever "do" a workshop manuel for said Classic? Richard? regards,J.B.

[Steve Gee]

Hi john, for the classic wiring diagram have a look at the startright web site, Graham has a downloadable diagram in the rotary technical section.

[MrB]

Graham's downloads are a very good facility. He told me recently that if anyone has any other useful docs that are scanned he is happy to make them available alongside the others.

[Malc]

On the subject of Tacho's, The Motometer one should never be wired to the IP2 generator signal as it will scrap it!About 18 months ago, bought one off E-bay that was ex-MOD stock, Had to send it back as someone had obviously fitted it to an IP2 without fitting the appropriate modified replacement ign unit.Still have all the service releases that were sent out to police operators for the IP2, but dont know how relevant they are now. When the Commander was introduced the service releases stopped!Some of the documents are not in very good condition as a car mechanic put a leaking fuel tank on the desk! Hand to head and say 'red' backwards.

[andygbsmith]

Hi Richard,I found the plug from the alternator burnt and the insulation brittle.I have done as you suggested but when time allows I will replace the wire as well, to soon to say if its the cause of running on one rotor but the High beam idiot light is working now as well!! I thought it was the lamp gone?On a new topic, one of my issues with the bike is the tank range and in order to fill the tank to max you have to rock the bike back and forth on the stand to move the air. I was going to drill a couple af small holes in the tube that drops down from the filler neck, any thoughts.Andy

[Richard Negus]

I was going to drill a couple af small holes in the tube that drops down from the filler neck, any thoughts.Andy

Yes! Don't drill as swarf will almost certainly end up in the bottom of the tank ; not usually a problem, but something else to clog the strainer on the fuel tap.Instead, use a round punch and the coal hammer to deform the existing hole bigger ; go to at least 6mm, or even 8mm, and be careful filling to the last drop.Whatever you do, don't fill it and then park it on the sidestand while you go for a coffee ; there'll be a strong smell of petrol when you return.Fill and ride , gained from personal experience of my own Commander.If you have an aluminium tank, ignore all the previous and drill away to your heart's content.R.

[Dell Boy]

I have found the only solution for the three yellow alternator wires self destructing is to solder the wires together with hard solder & sleeve them with heatproof sleeving. I have used plastic block connectors in the past & they have melted as well. You used to be able to buy ceramic block connectors from electrical wholesalers. These I think would do the job if they are still available. Derek.

[Richard Negus]

when time allows I will replace the wire as well,Take it right back almost to the stator ; the wire looks tinned but is difficult to solder at the burned end and the yellow insulation will have become brittle too. If you make the wires extra-long, you can then put the connector in a cooler place the High beam idiot light is working now as well!! I thought it was the lamp gone?Probably coincidence, or the local gremlin got burned with the extra voltage and turned the light back on again.

Don't you just hate it when that smug sticks his nose in ?Ba***rds done it again !

[Interpol2471]

I am very happy to say that the face does not make me or give me a red faceCalm down Calm down

[Interpol2471]

what happened to ?

[Richard Negus]

what happened to ?

Just a bit tired and emotional ; I'm usually like that after returning from boating.Rotor circlip is 50-0153 ; it's not a standard circlip, wound from rectangular-section strip rather than punched out of sheet steel.R.

[johnbirchjar]

Hi guys, checked the make of my tacho,it's the German one,so I am now on the look-out fore the French variety,I tried to source one via Grahams shop web site, but the system told me that it did'nt recognise the item!! (N.M.L have only the German variety.)so the search continues,regards,J.B.

[andy588tt]

HiInteresting about running on one rota My F1 has had the same problem for a while now runing on one rota it can happen any time Ive never lost the tacho through fitting a new plug seems a quick fix on the day But Ive known the problem to come back after 20miles or 3000miles, it always seem to happen when Im in the Isle of Man or miles from home. The plugs are the same color with no sooting they are a nice brown I use NGK C8, Ive swopped plugs over and the other rota stops working So I know Im eating plugs on one Rota I know the plug could be overheating with carb to lean but the colors are the same on both plugs and it goes very quick Ive got NML Ign box Ive fitted two sets of new leads and coils The carbs are clean and fitted new float needle jets,cleaned Fuel tank tape filter as well as new inline filters, its just a long process of elimination,.When one of the rotas stop firing the pulling of one rota is not good and I dont like riding home with the problem.I never had this problem with the Interpol or commanders I remember in the seventies and the two strokes we use to always have to spare set of plugs but its a bugger removing the fairing top and fuel tank on the M62 or the M4 to get to the plugs, I run on Texco ursatex? low ash. and have gel battery fittted behind the seat with Ign box to keep it all . Ill over come this problem Im sure but it is a tease. Have I missed anything please advise. Ride Safe Andy588tt

[johnbirchjar]

I'm no expert but by my own experiences in the past I reccon you have an electrical fault,is the NML ign; system new? if so have you replace the ign; triger switch? if no to either try the switch first,if yours is the same as mine(Classic)I have a spare one I could loan you to try out,regards,J.B.

[johnbirchjar]

While on the subject of ig;n triger switches,Boyer no longer stock the orignal ones fitted to the air cooled engines,the one they sent me last year when I was having "electrical" problems, I had to "modify"(ign; trig; switch was not the problem,hence I now have a spare one)J.B.

[Dell Boy]

Bitter & expensive experience has taught me over the years not to keep going on one chamber because the dead one is constantly being washed dry of oil by the petrol mix. The result can be a smeared side plate. The other problem I have encountered is one plug getting the bulk of the electricity causing the other to fail much earlier due to the carbon causing resistance & not a powerfull enough spark on that side to overcome it. Derek.

[johnbirchjar]

Hi guys, just had another look at Grahams "stores list" found a tacho he has for sale,for an IP2,"no sutable for Classic's" the add said,have I been in ignorance all these years? I thought they were interchangable?Please advise.regards,J.B.

[Richard Negus]

Hi John,Two different brands of tacho :. if it says 'Made in France' on the face, it was fitted to early IP2's, the numbers don't fall off, hardly ever goes wrong, and can be fitted as a replacement to any air-cooled (including Classic, with a bit of extra wiring). It was driven by the alternator a/c pulses.. if it says 'Made in Germany' on the face, it was originally fitted to Classic and can be fitted to IP2's which have a replacement ignition unit with an extra yellow wire, or IP2's that have been converted to Boyer or digital ignition. It takes its signal from one of the ignition coil signal wires. Some MOD IP2's were fitted with this type as original equipment when stock of the French unit were used up.To complicate further, there are two types of German tacho :. early ones had a round terminal block on the back with screw fixing for the connections ; prone to problems, and the numbers fall off.. later ones have a rectangular block with short 'flying' wires for connections ; more reliable but the numbers still fall off.To the best of my knowledge, the French unit (made by Veglia) is unique, being driven by the alternator, and was specially made for Norton. Here endeth the lesson !R.

[Dell Boy]

What do you want a tacho for? I never look at mine except for when it is ticking over exceptionly slowly [200 revs] to see if the engine is still running when at a standstill. Other than that I just rev the nuts of it when the mood takes me. I wonder why they bothered fitting one to a rotary especially as the rev limiter stops you going crazy. It`s just extra cost,weight,complication & something else to go wrong. Derek.

[BANJOMAN]

I took my commander off the road 2 years ago when it had the bouncy tacho and fluctuating revs problem. It has a rebuilt engine now and fired up yesterday for the first time. Noticed the tacho needle is still a bit 'bouncy'.Not able to take on the roads yet but will be interesting to see if the fluctuating revs still makes it horrible to ride. Hope Not!!!Could there be a problem with the Yamaha clocks causing this?? I am running one of Startrights ignition boxes.

[Richard Negus]

I believe the Japanese tachos, both Commander and F1, to be utterly reliable so I would discount a tacho problem causing an ignition problem. Even an intermittent fault in the wiring to the tacho is most unlikely to cause an ignition fault, unless that particular yellow wire is shorting to earth somewhere. Again, unlikely.More likely is that you have an intermittent ignition fault that is upsetting the tacho. I also believe the Startright box to be utterly reliable, which then leaves either a problem with the trigger, the side stand cut-out, the voltage regulator, or the wiring.First, un-plug the sidestand switch and see if it's better. If so, adjust the M6 bolt on the stand so that it pushes the switch plunger further in.Then un-plug the trigger and check resistance with a multimeter ; it should be 160 ohm +/-5. If vastly different, replace it.Then check battery voltage with no lights switched on ; at no engine speed should it read more than 14.8 - 15.0 volts ; higher suggests a regulator fault where high voltage is upsetting the ignition ; check the regulator earth connections go to the same fixing bolt and are clean ; check the 3-way connector block from the generator - they often corrode, overheat, melt the plastic housing, and make an intermittent connection.Then check the trigger air gap - which involves taking off either the water pump or the gearbox outer cover ; it should be 0.4mm / .016".Then check all the wiring connections ; the three nine-way connectors blocks by the r/h joint of the front fairing are the usual culprits - and the most diffult to access. To do this job properly, it's often easier to take off the complete front fairing assembly (including the speedo cable).If your bike is high mileage, there may be a bad contact in the ignition switch or in the kill switch.There's a few things to keep you busy 'til the weather gets better !R.

[BANJOMAN]

Thanks RichardThere is no sidestand switch as it came off (was removed) just after I got the bike new in 1992. Didn't rewire it after the rebuild.Voltages seem fine so regulator should be okay. Wiring harness is new one piece type so connections are less than original. All original ends of old remaining wiring cleaned up to gleaming finish!!!Graham rebuilt the engine so trigger gap should be okay. It was a new trigger before I took the bike off the road. New ballast resistor also tried.Once I get the bike on the road in anger I will see if problem persists if it does then I may look at the ignition switch as a possibility.Thanks for the pointers.StuartCommander 4166

[andy588tt]

Hi AllJust a quick update to my F1 cutting out on one cylinder, read back through the thread. The update is the three year old NML Ign box was sent back to Peter at Rugeley just before the close down. Peter passed the Ign box onto the person who made them and it checked out to be fine, I had a call from the kind chappie who knew the problems I had and updated my Ing box to his latest power curve for a small fee. This was great but I still had no answer to the problem of cutting out on one cylinder.I checked out the wiring again taking apart the block connectors one by one. When I separated the alternator block (which looked fine on the outside but the spade terminals looked glazed inside) when apart I cut off the block and soldered together with new longer wires with heat shrink on each joint and have placed the "new hard wired joints" in a air stream. If I need to remove the alternator I can hook the wires out of the way. This has been done for some time now and I think I have solved the problem.Ride safeAndy