mystery fault....

[jamie92j]

well my k100 just started a strange fault

its only got 36k on

splutters and coughs when throttle held around 2-3rpm

the really strange thing is the speedo gauge also rises up to around 20mph on idle (when at standstill!)

im thinking electrical, maybe regulator? as the coughing and spluttering is similar to a f650 when the reg/rec went on that

any thoughts?!

i need it fixed asap for work!!

[wmax351]

Likely the throttle position switch is misadjusted, etc. Just unplug it for the moment. Its located at the aft side of the throttle bodies.

[jamie92j]

the throttle position switch has not been touched though, so surely its unlikely to move its self?

the bike was ok from cold, seemed to happen after 5-10 mins of riding once the bike was warm

which makes me think coils?

Iv checked the volts across the coils and that is fine (around 12v)

Iv also checked the resistance across the primary winding as per Haynes manual and there around 5k which also seems in spec although i don't have exact data for these

Trying to check across the secondary winding but the manual is not all that clear, im unsure of where the HT lead terminal is and where to measure from

any more thoughts?!

need the k100 experts help!!!

Bike is a 1989 k100lt, 36k on clock, UK model

[TimTyler]

... seemed to happen after 5-10 mins of riding once the bike was warm

How about the HES - hall effect sensor?

[jamie92j]

thought it could of been that

but the bike still idles fine once warm

it just wont rev up

[TimTyler]

it just wont rev up

You tried replacing the fuel filter, right?

[jamie92j]

doh  :embarass:

start with the basics....

[jamie92j]

been thinking about it and think its unlikely to be fuel filter (although i will check it)

Just been out to start it now after its rested for around 5 hours and its fine!

Problem only seems to start when it gets up to normal temp

[wmax351]

been thinking about it and think its unlikely to be fuel filter (although i will check it)

Just been out to start it now after its rested for around 5 hours and its fine!

Problem only seems to start when it gets up to normal temp

sounds exactly like the hall sensors. easy and fairly cheap to fix with the honeywell sensors.

[jamie92j]

honeywell sensors?!

whats the kind of price i should be paying for a new HES?

[TimTyler]

There's a $50 used K75 Hall Effect Ignition Trigger listed at http://marketplace.ibmwr.org/ads/view/id/203891 

Not sure if that'll fit your K100, or even if that's another name for a HES.

[WoahGold]

K75 hall effect sensor will not fit a K100. The sensors are aligned differently.

Duck has one though: http://www.kbikeparts.com/

[Inge K.]

The sensors itself is similar 75/100/1100, but the complete unit is different on a 75.

To test: remove the T-shaped cover, heat up the sensors with a hair dryer or similar (cold engine).
Start the bike, if it`s the HES that is the problem...it would now show up far earlier.

Inge K.

[jamie92j]

thanks for all the input people

will test the HES tomorrow morning with a cold engine

Also i am over in the UK so ordering parts from the states could be an issue, but thanks though

Will try 'Motobins' if it is the HES at fault