F1 Sport Failed Starter Motor

[barney]

Hi All - I'm a newbie to this forum and a newbie to the world of rotaries. I have a 91 F1 Sport which was rebuilt by Norton in 2005. I've had the bike about a year now, and I have a few teething problems. The latest problem is critical as the bike won't even start!!Symptom- for a while now the bike has been difficult to start. It's slow to turn over on the starter, but slowly it will pick up speed and the engine will catch. This has been getting worse and worse over the last couple of months. Yesterday the bike failed to start on the button, but quickly fired up on a bump start. Today, the starter won't turn at all. The solenoid/relay clicks and the tacho jumps when I press the button, but the engine will not turn.My assumption is that the start motor has died? Anybody else have any other ideas?So if the starter has died, can I replace it easily? I have located the starter, removed most of the fairing, but can't get the screen/instrument cowl over the folks. Is this possible? is there a tick I don't know!Thanks in advance.Barney.

[Richard Negus]

Barney,It's unlikely to be the starter motor ; battery is the usual culprit. They don't like the standard location, buried under the tank, as they get hot and they don't seem to like constant trickle charging either. Check the acid level.The ignition won't spark if battery voltage drops below about 9volts, which it can do when the starter is operating with a sub-standard battery.Disconnect your battery and try jump leads from a known good battery ; if it starts ok from cold, then replace your bike's battery. If it doesn't start ok, then the motor may be faulty.To remove it, remove both side panels and the hockey-stick shaped panels, pivot the main fairing about the indicators (no need to remove) , drain the primary oil ,and use a long hex key to undo the three screws on the starter. Disconnect the battery FIRST !R.

[barney]

Hi Richard,You where spot on. I took the battery off as part of dismantling the tank/fairing. I put the battery on charge, and it seemed OK. In a last ditch attempt before beginning with the starter, I tried the battery again without the tank fitted. I noticed a horrible sulfur smell, which immediately made me recheck the battery. It turns out the battery was bone dry, how it was putting out any voltage/current at all is a mystery.I refilled the battery with new acid, added some plate cleaning tablets and recharged it. Hey presto, we're off and running again!The battery was new this time last year. I've only done about 700miles with it. It has been on trickle/top up charge, but I'm amazed it's dried out so fast. Is that normal, or do you think it might be over charging?I'm using a standard lead/acid battery - are the sealed gel units any more reliable in your experience?Also you might remember my bike - it has a twin seat convention. Is it possible to fit battery carrier under the passenger seat on a modified bike?Thanks again for the invaluable advice.Barney.

[Richard Negus]

Hi Barney,Glad you found the problem.As you read in my previous contribution, I have great reservations about long term trickle charging. It may of course be a fault with the bike's voltage regulator - not unknown with the original Kokusan and usually attributed to a bad earth connection at the regulator itself.If you put a multimeter/voltmeter across the battery terminals, it should read around 12.5 - 12.8 volts with the ignition 'off' and , with the engine idling, around 13.0 - 13.5 ; rev the engine and it should be no more than 15.0. If it reads in excess of that, you have a problem and the battery will 'boil'.Check the black/white earth wires from the regulator are making a good connection to the loom black earth wires.Your particular twin seat Sport has no space to relocate the battery to the rear ; there is enough space in the standard battery tray to fit a gel battery, stood on end.Not at NML at the moment and can't recall the battery type - something like YTZ12B.I think an Odyssey also fits, but had one that failed very quickly but was replaced under warranty. None of the Banner / Yuasa gel batteries fitted by NML have had any problems.R.

[barney]

Hi Richard,It looks like I may have a problem with my voltage regulator.I measured the battery voltage at 13.6v. With the ignition running the voltage went to14.7v and then to 15.45v just as the bike was warming up. The voltage was slowly, but steadily creaping up all the time.I'm assuming the regulator is the die cast, finned, box mounted under the seat? (Appologies, but I'm used to bikes with Zenner's!!) There are two connectors from the box, one with red wires, one with blue wires, and a black wire and a black and white wire that loops back into one of the fixing points for the unit. Is that liekly to be the reg?The b and b/w wire seem firmly attached. Should the outside of the unit be at earth? can I meansure the resistance from the unit to earth? or am I wasting my time and should I just buy a new reg to be on the safe side!If you think a new reg would be the best option - do you have the make and model number?Thanks again indvance.Barney.

[Richard Negus]

Barney,Yup, 15.5v sounds a bit too high.The three blues are the a/c, the reds are duplicated + outputs and the two black/whites are - outputs. The finned casing is just a heat sink and need not necessarily be grounded; the black/whites go to one fixing bolt and, on yours I think, the ring terminal of the loom only just reaches the other fixing bolt. As the finned casing has an anodised finish, it is not the best of conductors and there may be a high resistance between the two. Before spending cash on a new regulator, try removing the anodising at the mounting holes so there is a good electrical connection, or add a short connecting wire.If that doesn't cure it, then another regulator, I'm afraid.NML don't have any original Kokusan regulators left ; Graham at Startright may have some - and I think he also has replicas, made by Electrex.R.

[barney]

Hi Richard,Sorry to trouble you again, but I thought I'd give you an update and seek your advice.I've stripped the rear section of the bike to get to the reg. The connector for the reg is basically melted/corroded. I've attached a pic.http://picasaweb.google.com/lh/photo/cR ... ctlinkThis leads me to ask a couple of questions,Given the connector has melted - could this be caused by the failed reg? or it likely to be water in the connector that has caused it to short?Either way - should I replace the reg as a matter of course?Secondly - I've been having running problems with the bike for a while now. Here are the symptoms.1) Every now and then the bike will die on tick over or idle. It just stops. It will not usually restart for 40mins to an hour.2) Occasionally, usually in slow speed traffic when the bike is hot, I get a miss-fire. This feels like an oil'd up plug on my old "kettle", if I blast the throttle this miss fire will often go away for a period of time.3) Fast tick over - recently the bike has started to tick over at about 1.5 to 2k. I'm used to this when it's cold, but expect the tick over to drop when the bike is warm. That isn't happening - it stays ticking over at 2k.So here are my questionsre 1 is it possible we've been loosing electrics somehow. When the bike stalls I have lights and starter, but could the reg/connector have caused an HT failure?re 2 could this be caused by over voltage in the circuit? could the ignition box be failing at over voltage? Could that have been permanently damaged?re 3 is the higher voltage in the loom biasing the a thermocouple that might set the tick over some how?Sorry again for all the questions.Barney.

[Richard Negus]

Hi Barney,Answering queries from rotary owners is no problem to me - but be aware that if you don't get a reply within a day or two, it means I'm away from home. Also be aware - I have been known to speak absolute rubbish !The photo shows something which has been fairly common on Commanders (which use the same generator and regulator) but relatively unknown on F1's. Corrosion in that connector causes high resistance and overheating sufficient to melt the plastic. Check the same connector at the engine end too ; corrosion is usually due to either low clamping force in the terminals or to salt ingress.You could replace the failed 3-blade connector with a conventional household 'chocolate-block' connector or go for something waterproof. However, waterproof plug/sockets for 28 strand wire tend to be on the large side. You could also make a permanent connection by soldering the wires and insulating with heat shrink.A bad a/c connection like that will result in a varying dc output and will certainly affect the ignition unit performance. Repair the a/c wires first and then see how it performs ; all the symptoms you describe sound like they're associated with a voltage problem.As I don't have access to the bike's history, and the memory isn't what it was, does it have an original Boyer igniton unit (plastic casing) or a digital (metal cased) unit ?R.

[barney]

Hi Richard,Thanks again for your help.I hardwired the three wires from the rotor to the reg, but I'm still reading 15.3v across the battery. It doesn't seem to climb about 15.3v and the tickover never got above about 1.5k. At one point it dropped to about 600rpm, but then went up as the voltage climbed to around 15v.I noticed that if I put the lights on main beam, and pull the brake on the light the rear light the tickover drops. Not quite to 600, but around the 1k mark.I think the ignition pack is metal. Is it the unit right at the back of the sub-frame under the passenger seat on my bike? It has two screw connectors on it?I'm guessing all this mean I deffinately need to replace the reg. Is there anyway of testing to see if anything else has been blown?Best...Barney.

[barney]

Hi Richard,I'm now convinced I had a regulator problem, and I'm now confident it's fixed!!!I went to see the guys at Electrex today. I can not say enough good things about them.They have supplied me with an RT99 rectifier and regulator. This is the closest match to the one that I had taken off the bike. For all Inty and Commy owners, this is different from the RT10's your bikes use!!The guys at Electrex went out of their way to find a unit that would fit, and supply replacement connectors.They also tested my old unit. The have a simulator, which showed the unit was putting out 15.8v and was still climbing. They asked if I could leave the old unit them as they like to take them to bits!!!Here's some photos of the newly installed reg. This now gives 14.8v across the battery max.http://picasaweb.google.co.uk/lh/photo/ ... rectlinkAs we've solved this problem. I'll start a new thread on the other topics - hopefully this will make it easier for others to find/solve these problems.Thanks again Richard.Barney.