Hi all...new to the forum hoping someone may be able to help. Bought a K100 RS '91 a couple of months ago. Initially fine then started cutting out when hot. Initially thought it was the Halls Sensor but when on a test ride to check coils where good when hot we had smoke and melted plastic as the right handle bar switch gear and main loom burnt out in six locations.

Have now replaced main loom with a second hand one. Tested for shorts and all seem ok. All electrics work (with no smoke) although had to re charge the battery first. Howver now:

1. Fuel pump is not priming
   
2. Fuel gauge always reads full (tank only half full)
   
3. Gear indiactor always reads 1st (sometimes flickers to '0')
   
4. Starter motor want turn over unless clutch is in (despite being in netrual)
   

I also had the tank of a drained while I was waiting for the new parts so has been dry for a couple of weeks.

Any help advice would be appreciated. The K was bought as an economical commuter (110miles a day) would be good if this turned out to be the case.

Many thanks in anticipation of someone pointing out something obvious I have neglected to do.

If i am correct the reason it won't start without the clutch lever pulled in is because the bike thinks your in first gear. (safety feature) so once you sort out the gear position indicator that should clear that fault. look at the connections and clean and double check earths are all good.

Other than that i would need to have a peek at the wiring diagram to see if there is something common to them all....

to which.... if you have a look at the interactive diagram on the Portal tab, and click onto Fuel Pump you will see it in the bottom left, you then have a couple of wires going to the fuel level display, and then feeds back to fuse 6 .... those are the first area's that i would start looking in, Deoxit is a highly reccommended connector cleaner so would be worth a squirt on each of the connectors, making and breaking it a couple of time.....

Hope that the above has helped a bit...

Many thanks for the useful advice.

giles4060 wrote:Many thanks for the useful advice.

Not a problem, dont forget to say hi in the New members section... and you will get to meet some of the characters around here...

giles4060 wrote:

1. Fuel pump is not priming
   
2. Fuel gauge always reads full (tank only half full)
   
3. Gear indiactor always reads 1st (sometimes flickers to '0')
   
4. Starter motor want turn over unless clutch is in (despite being in netrual)
   

1. Is the sidestand switch reconnected, after the harness change?
2. Could be a short to ground somewhere between the level sensor and the instrument.
3. Here is a "how to" check your GPI switch and wiring.
4. Twincarb have allready explained this good.

Inge K.

Thank you will try these out and let you know.

Check out the 4 pin connector from the tank to the harness as often the female part on the harness goes O/C when the pin receptors open out due to being seperated quite often. Just carefully squeeze them or replace with a new 4 pin connector that is available from auto stores.
This could be the fuel pump and gauge problem.

Thanks all. Rather embarresingly I went out to the garage tonight to embark on an evening of fettling.

Quickly realised I had connected the coonector from the tank to the wrong one on the harness. As I have been doing the job slowly in stolen hours here and there I had forgottent that there were two identical connectors down that side of the bike.

Am now left with just a gear indictor that is a little inaccurate (reads 4th or 5th) and a bike that no longer recognises neutral. I suspect may be the connector onto the clocks which I will remove and clean later. Pump now priming and level sensor working. Engine now running and no smoke or melted wires

Feel a little daft. Thanks for the helpful advice.

No worries mate, we're not born knowing all. Each of us has some tales to tell

good news giles ....keep at it ..cheers !!!

I thought the gear indicator connector and the fuel connector were on the same frame rail beside the electrical box. is this so any one? may be the area to search in.

I think so as these were the two I got mixed up. I had it in my head that they were all diferrent connectors. Bike all back together now and now left over bits.

Now idling hi though and slow to return back to idle. suspect the throttle cable caught someone where.

Not a job for today.

Appaling typing.

Know starts and idles fine until revved....then remains high and returns very slowly. Throttle seems to be operating fine....returning against the stop at both ends.

Any ideas anyone?

Do the throttle butterflies close or does the cable return leaving slack with the butterflies open and those slowly creep closed until they catch up with the returned throttle cable?
Regards,
K-BIKE

Thanks K-BIKE I will check tomorrow.

Could it be a displaced return spring??

Sounds plausible. Not sure where to find it but will consult the manual. All a bit of a learning curve. Whilst not a complete novice at tinkering it has mainlybeen general maintainence previously and general blacksmith's mechanics on an R.

Thanks for all your help and advice.

giles4060 wrote:Appaling typing.

Know starts and idles fine until revved....then remains high and returns very slowly. Throttle seems to be operating fine....returning against the stop at both ends.

Any ideas anyone?

Removed the tank and repacked the wiring harness a bit looser. Throttle now behaving. Bike is now back on the road.

Now have a dodgy gear indiactor (thinks neutral is 4th and all other gears are fifth) and have to pull the clutch in to start (and no neutral light). See from other posts this is not uncommon and and have run out of energy to worry about this at the moment. It can join the list with the flashing ABS light!

Thanks for all you help. Great forum!

a good result ...!!

Good work now you can go ride it anyhow, once you recharge the batteries abit you might consider disconnecting the gear indicator and trying that one again, there has to be a simple reason why it wont play the game.

K75cster wrote:Good work now you can go ride it anyhow, once you recharge the batteries abit you might consider disconnecting the gear indicator and trying that one again, there has to be a simple reason why it wont play the game.

I did disconnect at the instrument end. Even gave it a little squirt of WD40 against my better judgement. I think some of the connecters may be pushed down a bit far to make connection. Thought better of removing the clocks as the bolts were so corroded I could see that this was going to create another sub list of jobs. It may be a problem at the other end but this was fine before meltdown so hoping not as I understand the switch at the other end is a pain to get to.

Yes the little pins require patience to get right, but I was thinking of the 4pin plug beside the frame tube it also may be dirty on one contact throwing the others off and causing the error

K75cster wrote:Yes the little pins require patience to get right, but I was thinking of the 4pin plug beside the frame tube it also may be dirty on one contact throwing the others off and causing the error

Thanks for the tip. I will check. You're right changing the loom was a good way to get to know my way around the bike.

Its good to get to know the bike. we play in the shed so we can play on the road, sometimes we feel all fingers and thumbs, then someone on here reminds you they're using similar fingers and thumbs

I personally do not believe WD 40 has any place near electrical contacts in plugs and sockets, use DeoxIT instead that is the right stuff to use.
Regards,
K-BIKE

Mmm....rather frustratingly after a week of trouble free riding the bike has started repeating the initial fault.Spluttering then cutting out when hot (normally 30 min of riding). Leave it a 5-10 mins and is fine until it warms up again.

I have a spare Halls Sensor which i will replace but if anyone has any further wisdom to share I would appreciate it.

Can anyone enlighten me why there are two connectors from the main loom to the coils but only one connector at the coil? Should this be taped up. Just shorted it of the frame by accident when i was checking routing of wires (i know i should have disconnected battery first).

Green/yellow I assume, it should be one connector to each coil.

Inge K. wrote:Green/yellow I assume, it should be one connector to each coil.

Sorry i'm an idiot. Didn't explain that very well. It's not the connectors to the coil but to the accessory socket that sits on top of the coil. Is there supposed to be a spare one or have i missed a connector somewhere? Brown and Grey / Red.

I`ll guess you got a wiring to a double socket setup.

The genuine T-connectors used for the power sockets is well isolated, and difficult to short......aftermarket?

Double socket wiring....# 11:

The metal crimps inside the plastic housing are sitting slight proud of the plastic housing. Contact with frame is therefore quick easy. Still not 100% that this may be causing the problem though as it seems to run fine when cold.

If it`s a genuine socket wiring it`s connected via fuse #4, and the only thing connected to this fuse.

Inge K. wrote:If it`s a genuine socket wiring it`s connected via fuse #4, and the only thing connected to this fuse.

Thanks Inge thats really useful. I will take out fuse 4 and see if the problem persists.

Seems the Voltage Regulator was the problem. Thankfully seems to be running fine now.