Spark plugs and hot start

[spanner boy]

Ok Norton IP2 back on the road again after a very long lay-up. Bike is running well but an old problem has resurfaced. Hot start problems!!I used to think that this was a battery issue but I am now thinking that this may be a coil issue or a problem with the surface discharge plugs. I am now thinking of renewing these And wonder what the concensious is on the best replacements. The problem Is that the bike starts well cold but has problems part warm. If the bike does not catch immediately it floods and struggles to start then without a push. Any help would be appriciated.

[Richard Negus]

You could try NGK C8E but I doubt it'll make much difference. Cold start ok/hard to re-start warm or hot is a classic symptom of low compression.Probably time for an engine overhaul.

[spanner boy]

The problem is that this engine was reconditioned by Norton in the early 90's and still had this symptom. Used to have the obligatory bag of plugs then but never really solved the problem. A friend who worked for the police seems to remember that this was a problem with the bikes then as well.

[Dell Boy]

I agree with the guru [richard]. Had all this in the 80`s with my first IP2. I`ve got an ice cream tub of barely used plugs. Low compression even after Norton factory rebuilds. Only brand new plugs would start it when hot.I bought the door to the spares office at the Shenstone clearance sale in memory of all my hard earned cash that disappeared through it mostly for spark plugs.Try this.When very hot, squirt oil into each chamber to improve the seal & if it starts readily you are down on compression. Give Redex a try to see if it ungums the seals. Hopefully the plates are not scored.Derek F.

[spanner boy]

Ok I'll give redx a try. The engine starts very well cold and hot. Part warm seems to be an issue, the engine does not smoke, there is no chuffing noise and performance seems good. Plugs are not sooty. Idle quality is very good thefore no obvious misfire. Is it possible to do a leak down check on a rotary engine if so what should I expect?