Help needed in Norfolk with airhead problem..

[follow me]

Hi,

I've been running my old R100 84' for the last few years and after a trip around Europe last year I decided on a rebuild.

Alls going well and it's running fine, until last weekend. Went out for a ride around Norwich and after 10 miles breaks down. Runs really rough, backfires... Gradually getting worse until it dies. Stand for 10 mins, then starts up fine again. 10 miles later does the same thing. This time I had to bump start it... My fault cranking the battery over to much.

I think it's the coils as they are old or maybe the bean can is on its way out, the last time it broke down the rev counter was flickering. I'm sure I read somewhere this was a sign of a bean can failure??

Any ideas ?

Many thanks Ian

 

[DrFarkoff]

Sounds good for Bean can failure

I did one when I was at the dealers 24 miles exactly until the sensor heated up and then it did what yours did Let it sit 20 minute and bingo away it went again

Ah the good old days when we used to get Airheads in


OOPs edit Heat sink on the ignition amplifier also a possibility Black box on alloy thing up under tank

 

[Box’a’bits]

More likely to the the ICU (under the tank, with a alloy heatsink). These have a habit of deteriorating when they get hot, die, then will spark again when they are cold. They also affect cold starting - fires on one cylinder, & then the other fires later.

Easy & cheap enough & to replace. The ICUs are also used for some Mitsubishi cars

 

[bumpmuncher]

I believe the "Intermotor P/n 15000" is a direct replacement for the ICU
LinkyEbay Linky or avalable from your local motorfactors

 

[Rob Farmer]

Lucas DAB400 works as well. Fitted to loads of cars in the 80's http://www.ebay.co.uk/sch/Car-Parts-/14239/i.html?_from=R40&_nkw=dab400

If you have a kickstart you need a different ignition module though. The normal module powers down the coil if it doesn't see an input from the hall effect sensor within a second or so. it then wakes up when it sees another input, unfortunately you cannot kick fast enough to wake the module and provide a second pulse. The kickstart module holds the power to the coil for a lot longer giving you chance to wake the module and get a second pulse in.

The original modules used to keep the coils powered up indefinitely frying the coil if you left the ignition on.

Sounds more like a Hall sensor problem to me though. Take a plug out and rest it on the cylinder head. Flick the kill switch on and off several times. If it sparks then the problem will be the hall sensor in the bean can.

Steptoe has a gadget for testing the ignition modules out.

 

[follow me]

Thanks everyone for your input... More expense by the look of it then.

I was looking at getting an upgraded Hall sender from Motorrad Electric in the states I now also see that Motobins are doing one as well. Both also come with an upgraded ignition module. So some savings To be had... But not what I really want with the new GS draining my funds. There is a limit to how much you are willing to spend on an old bike to get it up and running...

http://www.motoelekt.com/ignition.htm

 

[follow me]

Rob Farmer, it's defiantly the bean can then as when I turn on the ignition it sometimes just fires once....

 

[Rob Farmer]

Take the plug out and rest it on the head and flick the switch. You should get a consistent spark. The odd "phutt" from turning the switch is a bit random.

The other fault that matches your symptoms is a trapped bean can lead. I've done this myself and been stuck by the side of the road. The lead can get trapped under the front cover when you refit it after working on the bike and shorts out when hot. As the engine cools it all works again. have a look at the lead for signs of it being trapped (flat spots on the lead etc).

 

[follow me]

Hopefully that's it,

 

[Deleted account 220427001]

air head

Hi,

I've been running my old R100 84' for the last few years and after a trip around Europe last year I decided on a rebuild.

Alls going well and it's running fine, until last weekend. Went out for a ride around Norwich and after 10 miles breaks down. Runs really rough, backfires... Gradually getting worse until it dies. Stand for 10 mins, then starts up fine again. 10 miles later does the same thing. This time I had to bump start it... My fault cranking the battery over to much.

I think it's the coils as they are old or maybe the bean can is on its way out, the last time it broke down the rev counter was flickering. I'm sure I read somewhere this was a sign of a bean can failure??

Any ideas ?

Many thanks Ian

change the coil first its expanding and tracking when it heats up !