My '86 K100 RS is giving me grief when it sits at work in semi shade but hot weather (Perth Australia) 35 to 40 degree days.

The K starts easily and runs well to work in early cool morning, sit all day and for the third time now will only fire for a few seconds and not run on. Has spark, fuel (filter not blocked) but will not run.

Left parked in workshop overnight starts first hit next morning and runs fine in city traffic when I take it home a swap to my R.

I have followed Bertrand's fuel pressure check and pump and regulator appear to be fine.

Could it be possibly a dry solder joint or cracked board in the fuel injection module?

Any ideas.

Regards

Ian Wright (lefty108)

Would it be a problem with the air temperature sensor in the Mass Air Flow (MAF or air box)?
Check the page on the EFI troubleshouting. I tested the air sensor and made a graph with the resistance/temperature.
I would first check if the connections of the MAF are not corroded.

Thanks, will check this one. i have cleand and checked fuel injector and EFI connectors. can the EFI unit be opened for service/checking?

Lefty

Hi Lefty,
I would start with the simple bits check the temperature sensor as Bert suggests, that would be my first check if I was faced with your symptoms. Then I would be looking at bad connections through the chain to the EFI unit. I would treat all connections with DeoxIt as well.
Regards,
K-BIKE

Hall effect sensors... when hot if they're bad you have ignition cuts and finally no ignition at all... you can test them with an hair dryer. Remove the cover in front of the engine then start the bike (with cold engine). Now let it run gently meanwhile you blow the hot airflow on the sensors. If you get ignition cuts, you are on the way to solve the problem....

Hi All,
If the Hall sensors were bad wouldn't they play up whilst riding after starting on a cool day? The engine gets much hotter then than it does when parked in the warm or even hot sun. I would expect the bike to start misbehaving as the engine warmed up.
Regards,
K-BIKE

Thanks guys, it would appear the first thing to check will be the temp sender and air temp sensor.

thanks for the info

regards

Lefty108