F1 Exhausts

[kanonkopdrinker]

Is it just mine which don't go a light grey colour at the ends, even after miles of 100-110 mph riding? (The 'Commanders' which were with me had the expected pale grey colour at the end of theirs) - as do IP2s, Classics and RE5s when similarly thrashed - but the o.e. F1 pipes remain a dark brown sort of tone.Normal or not?

[Malc]

Does it matter if it is normal or not? if you are happy with it and it is running well, in the words of an old foreman of mine, he would say in a broad Derbyshire accent " let it develop youth".It is an indication of how rich or weak the engine is running at high rpm but there are only 2 ways to be sure, put it on a dyno and get an air /fuel ratio or with the engine at normal operating temperature on a stretch of road you know well with a lay-by, use full throttle for at least 30 seconds, flick the kill switch and coast into the lay -by and using your asbestos fingers remove those hard to reach plugs and check the colour. This gives a far more accurate diagnosis. They should generally be a very pale brown in the centre and almost white around the edges. Some engines are happy running richer though.3 possible causes spring to mind thet would cause top end richness;Slightly clogged air filter (it does not have to look dirty or have reached its service mileage)Float level a bit high or the fuel pump is forcing fuel past the float needle valves but both the latter would also cause richness lower down the rev range as well but this may not be noticeable if only slight.The type and quantity of oil being used can have an effect but as most rotaries are using the same types I think this can be discounted.If it aint broke, break it, erm ,I mean dont mend it.MalcPS The reason I mention not taking for granted that the air filter is OK is that I had a Suzuki GSX 1100 covert bike came in, the riders claimed it was not running cleanly at high rpm. As a rule, all the service items are rechecked even if has not long been serviced. having only done about 3000 miles on a replacement filter I doubted if that was the cause but another genuine filter cured it. A similar thing also occurred many years before on a CX500.

[graham]

The collector box takes a lot of the heat. The original F1 had a cast alloy collector box. I was told it caused a fright during initial testing when suddenly the bottom melted out and the short front pipe was suddenly producing a VERY loud unsilenced exhaust note. The subsequent redesign was of thick stainless steel and it gets hot. Looking inside the collector box, you see that lovely off white colour just like interpol and Commander.

[kanonkopdrinker]

Ah, that would explain why Gary MacKnight's F1 Sport - which has an aftermarket exhaust system, and no underbelly collector box, has that off-white colour at the pipe ends; while those F1s running with standard Norton pipes are like mine. Thanks peeps!