IP2 Temp switch

[gripper]

I'm pretty sure I need a new temperature switch to retard my ignition. Bike lights up then struggles to tickover at about 200rpm. I should have a red and green light on the digital ignition box but no. The workshop manual says RS 151 243 but radio spares catalogue on line, shows a little black pellet with two wires hanging out of it. I'm guessing this is the working bit inside the casing that is on the engine. Anybody got a cross reference for one of these jobbies?

[Richard Negus]

Dave,Try 331-540, which is a NO (normally open) switch that closes at 60 +/- 5 C to connect the two blue or purple wires together and tell the ignition unit that the engine is 'hot' and 'please can we have full retard'.You are assuming the switch has failed normally closed, giving the engine full retard when it's cold, hence the low idle speed.Before fitting a new switch, disconnect the wires either at the switch or where the ignition unit plugs into the loom and see if the idle speed increases.If it doesn't, then either the ignition unit has developed a fault or there's something else amiss.It might be something simple like a short in the blue wires.ps To which workshop manual do you refer? What you describe sounds like the working bit of the Boyer-designed thermistor originally fitted to Commanders. The temperature switch (with two blade terminals) has, I think, a bi-metal strip inside that suddenly changes from NO to NC at a predetermined temperature.

[gripper]

Thanks for that Richard, The spec came from the IP2 Police workshop manual and that refers to the rest of the system as spark rite ignition and gunton retard unit etc. I've ordered a temp switch through a colleague from CPC and their cross reference is SW0318. I'll let you know how I get on in about 2 weeks as I'm away on holiday till then.Dave

[Richard Negus]

Now I understand!The early IP2 twin rotor idle had its temperature switch screwed into the back of the right hand air transfer port. Almost impossible to access and not in the best place to monitor engine temperature.That switch was made by Norton using the RS switch you describe glued into a threaded brass part with flying leads to connect to the harness.

[gripper]

Correction to the component number from CPC it is SWO3181 cost was £2.62 for two of them their website is www.cpc.co.uk and order line is 08701 20 25 30 Fitted it in minutes, well a few actually and does exactly what it says on the tin