No Start - Ideas needed

[Vespa no more]

Basically: (replacement!) key turned to on... nothing except instrument backlight on.
K100RT 1984 107K kms

Am repeatedly blowing instrument fuse (top 7.5)
Have put into gear and rotated rear wheel ... two turns ... still no neutral light nor starter motor response

Am wondering if starter relay has gone. Thought I remember hearing a sizzling sound when reconnecting the battery and the key was in "ON" position.
Any way to check relay apart from replace with new?
If ignition barrel and connectors faulty - were not separated in removal

Other details: Recent activities (in case something was responsible)

Ignition barrel removed (following lost key), new key, turns easily and into the 3 positions. Tank fuel pump comes on... not every time.
Instrument display had been opened, dielectric grease onto the speedometer pins (not fully removed. Gave up on removing tach needle (to replace gear indicator LCD) for fear of breaking it.
All wires are free / not pinched
No neutral light & top fuse blowing is new
Disconnected rear lights and removed tail section, (NB top fuse serves instruments and back light), sprayed frame and underside of seat, rear lights cleaned and sprayed with INOX (marine WD40)
Timing chain cover was removed (Hall effect sensor threaded removed and returned to premarked position when screwed in)
Final drive off and lubed...

At a loss at the moment...
I'm thinking ignition ... should I check with multimeter????

My appologies if this has been asked many times.

Thanks

Guy

[The Mighty Gryphon]

Have you checked all the connectors under the tank?  Does the starter turn?  Did you take the opportunity to service the ignition switch when you had the lock out?  Does the headlight come on?  Turn signals?  Brake light? 

Be grateful you don't have ABS on your bike.

[Vespa no more]

Headlight works, indicators and horn work
brake light lit when turned on but not activating when pedal pressed (did just replace rear disc and pads but did not mess about with brake switch),
connections under tank secure (relay box)
No sound or noise from starter motor
Did not service the ignition switch - probably because my focus was on the key. Fairing is off and can have ignition switch back out in 15 -30 minutes.


Have been alerted to K1100RT 1984 and am thinking of purchase. What can you tell me about these bikes? Is not going - fuel pump screwed and THROWN AWAY!!. Might take my fuel pump out and new battery and see what happens

GF

[Vespa no more]

Tried to post this earlier... seems to have failed.

K100RT 1984 107K kms
Basically: (replacement!) key turned to on... nothing except instrument backlight on.

Am repeatedly blowing instrument fuse (top 7.5)
Have put into gear and rotated rear wheel ... two turns ... still no neutral light nor starter motor response

Am wondering if starter relay has gone. Thought I remember hearing a sizzling sound when reconnecting the battery and the key was in "ON" position.
Any way to check relay apart from replace with new?
If ignition barrel and connectors faulty - were not separated in removal

Other details: Recent activities

Ignition barrel removed (following lost key), new key, turns easily and into the 3 positions. Tank fuel pump comes on... not every time.
Instrument display had been opened, dielectric grease onto the speedometer pins (not fully removed. Gave up on removing tach needle (to replace gear indicator LCD) for fear of breaking it.
All wires are free / not pinched
No neutral light & top fuse blowing is new
Disconnected rear lights and removed tail section, (NB top fuse serves instruments and back light), sprayed frame and underside of seat, rear lights cleaned and sprayed with INOX (marine WD40)
Timing chain cover was removed (Hall effect sensor threaded removed and returned to premarked position when screwed in)
Final drive off and lubed...
New rear brake disc and pads

At a loss at the moment...

Having dismantled the ignition switch: readings are attached
Front lights and indicators and horn working. Rear brake light is on but not activated by pedal
Relays all connected and tight
Again removed the tail section in case of pinched wire - no evidence at all


My appologies if this has been asked many times.

Thanks

Guy

[Laitch]

Did not service the ignition switch - probably because my focus was on the key. Fairing is off and can have ignition switch back out in 15 -30 minutes.
My appologies if this has been asked many times.

If this has been asked many times, Guy? It's been asked and answered many times in the No Start section of the Workshop. You need to approach this in an orderly way. It looks like you've been there before, go to that section again and work through the three main No Start treatments. Right now, because you've disassembled it recently, clean your ignition switch then start through the diagnostics and treatment in the Workshop. Checking connections with a multimeter will be helpful.

Please update us with the results as you go.

[Scott_]

When you had the final drive off, by chance did you have the side peg plates off? It's real easy to pinch the foot brake switch wire when re-installing the mounting plate.

Do you have heated grips?

Check for a skinned wire around the head stock area, since you were in that area to remove the ign switch.

[Martin]

Follow Laitches suggestion follow the no start guide,. Is your battery fully charged, you can pull apart the starter relay and clean up the contacts. They sometimes weld themselves closed on low battery current. You have not mentioned whether you can hear the fuel pump operating, you can try applying power direct. You can pull apart the 4 pin connector and apply + to the green wire & - to the brown wire, as per Gryph a known problem spot. If you are blowing fuses there is a short to earth, using a multimeter and the wiring diagram which is available on this site, trace out the wiring. RBM has a test for the HES look it up. Refrain from jumping from one thing to another follow the guide and eliminate one problem at a time and then move on to the next.
Regards Martin

[Vespa no more]

Thanks for replies...

Scott: I did have the RHS peg mounting bracket off - so that'll be the first place for me. To support this the rear brake light was not operating.

I expect no chaffed wires up front. I have been careful there.
Multimetered the ignition switch and the readings seem all back to front.

Ref: Relay contacts welding on low current. I had a starter motor on a car die because of low current - so repeatedly milking the last bit of power on a failing battery to start something can create other issues (ie replacement starter needed). I took the C-TEK charger and new battery (Motobatt 21Ah) back to the shop because it wasn't taking full charge (only going to #3 on the LED display). He said that for the bigger motorcycle batteries, the car setting is needed (manual mentions any batteries above 14.4Ah - which basically means all BMW batteries). Oh, and while both items were in the car on the floor behind driver's seat, the dog (Kelpie pup) chewed the leads off charger.

Was retracing a lot of little things I had done to the bike recently - few of them electrical. Hence the head scratching.

Will keep you posted

Thanks again

Guy

[Vespa no more]

Scott: a stripper and a six pack winging their way to you.

electrical lead pinched between foot peg mounting bracket and frame. Once released everything was working - neutral light back on, fuel pump whirring, starter immediately engaging. Had me worried there. I was surprised that this would have disabled everything else.

rear brake light and driving light not working at the moment (was working initially before total failure of rear lights after approx 5mins) so I will begin working my way through the wires and switches. Power at fuse box. Will check the brake switches

After some reluctance to start... removed and wire brushed the spark plugs... bike took a while to settle into an idle (cut out a couple of times when throttling up from idle before fully warm)...

Because the anti-backlash spring (or bearing) is rattling and I want the bike on the road while it's not too cold (yeah yeah ... I can hear you snow bound Americans coughing and choking... I did spend a year in Colorado in 2012) I upped the idle (to 1,000rpm) at the screw in front of throttle body assembly (not the cable) and will change this when next in the shed.

then when revved to about 2,000 or higher a fair bit of smoke was coming from exhaust. Am confident it is not rings but rather incomplete combustion - will go through the usual suspects asap.

Will the screw adjustment have caused the smoking? I don't see how?

Will keep you posted

Guy Francis

[Martin]

Vespa blue smoke is oil, black smoke is fuel, what colour is your smoke. 1000 rpm is fine for the idle speed. If the bike has been left on the side stand they can smoke for a while this is normal, oil seeps past the rings while tilted on the side stand.  Apparently if you tilt the bike to the right after turning it off it will reduce the smoking. You can also leave it on the centre stand.
Regards Martin.

[Vespa no more]

Smoke colour light grey. Has been on centre stand for some time - so none of the standard concerns.

Is there a standard setting for the idle screw on each of the 4 throttle bodies (what we would have called the carbs)? I have a mercury manometer and did even them up as close as I could about 2 months ago. But the bike has not been on the road for anything other than a lap around the streets. There was no smoking then. At this time the main concern was the noise coming from the motor - which changing the alternator rubbers lessened significantly and now increasing idle speed to 1000 has eliminated.

I am wondering if it is running rich (NB smoke not black).

There is a device called Colourtune (seems to be designed for carbs) which I am wondering if anyone has used on either fuel injected motors and specifically BMWs.

http://www.carbtune.com/colortune.html

While this sounds like unneccessary expense and gadgets in the shed, it would be very useful shared among a group. I would've assumed that fuel injection wold eliminate the need for tinkering. But if you can adjust the air flow as I can on my '84 K100 (re: balancing load on all cylinders) then its clearly not a "set and forget... / hands off forever" item.

I will return screw to original position and take up idle with throttle cable adjuster. Then give the bike a few laps around the streets to see if that doesn't clear it. Just in case someone asks: fuel tank is clean, fuel pump was brand new 7 years ago (bike came off the road soon after = little use) filter clean, fuel 98 octane (no valve saver fluid used), injectors serviced and clean, fuel hoses replaced, plugs gapped and clean, battery new and charged.

And again, this thread has diverted off topic and should be moved elsewhere

Regards

Guy

PS Martin... is it you working on your mates multitude of motorbikes... any joy?

[Martin]

Vespa a good run with a 1/2 bottle of Caltex Tectron will often sort out problems. Two 0f my mates bikes were prodigious smokers but eventually settled down. I had a lot of trouble trying to get my CO  mixture correct three  lots of experts stuffed it up. So I bought a cheap, for a gas tester Gunson G4125 Digital Gas Analyser. However there are alternate ways to adjust this, one is called the lean drop method look it up on the forum or net. The other is a check that is built into the bike, with the bike idling at 1000 RPM push the green starter button, if the CO is correct there should be just a slight increase in revs. In order to adjust this with any method, you need to access the idle mixture adjustment screw which is under a rubber plug situated on the front RH corner of the air filter housing. once you have removed the plug you insert a 5mm allen key to richen the mixture, screw in the adjuster to lean off screw it out only do this in very small increments. But before you do this you need to find your starting point by carefully screwing in the adjuster and CAREFULLY counting the number of turns until it bottoms out ( I think it should be roughly 4 turns ). This will enable you to return to the initial setting at anytime. The bike needs to be up to temperature to do this. I don't know which of the two methods is the most accurate but I suspect it may be the lean drop method out of the two. Personally I would just ride it for a while and see if the smoke settles.
Regards Martin.

[Vespa no more]

Carefully / roughly

Brought a smile to my face

"CAREFULLY counting the number of turns until it bottoms out ( I think it should be roughly 4 turns )"

We're talking a precision instrument here ... that someone put adjusting screws onto. That can only lead to one thing... tinkering

Unfortunately, I have downed tools ... job application and family have assumed a higher priority. But I will manage to be drawn into the shed at some point this weekend.

GF

[Scott_]

Something to think over with the engine noises, I'd run some MMO or similar cleaning additive in the oil. About 1oz per qt of oil.(not to over do it)
It can help clean up the starter sprague assy, clean up the rings, etc...
It may take a couple of oil changes worth of running to make any noticeable difference, but it will help. And cheaper than a tear-down.
You will see it in the color of the oil. As it works, the oil will get dirty sooner.