MD90 carburetor gizmos

[Harps18TV]

I was tinkering with the MD90 & looked at the carb. & noticed three sets of wires going to it. There were two inserts on the top of the carb., for want of a better explanation, with wires attached & another set of wires going to something that looked just like a small copper cylinder bolted under one of the brass nuts for one sensor(?). Any ideas what they are or could be, anyone? Sensors of some description I guess, but I can`t find a circuit diagram anywhere on the WWW to give me a clue - could it be to do with the CDI unit, but why 3?

[loadedtoad]

2 carb heaters and 1 temperature sensor
according to cmsnl

https://www.cmsnl.com/honda-md90-1999-x ... tfmq-DQiV4

[Harps18TV]

Mmmm, ok, but what do they do & why two? I don`t have a heater switch on the bike, other than the one for the handlebar grips. I remember years ago when I used to drive a diesel van sometimes & you had to turn the ignition to heater for a few seconds, but how does a carb. heater work & is it really necessary? As far as I know the C90s don`t have them & they`ve made millions of them! Still puzzled, but thanks for the link.

[wightegi]

In cold weather the fuel atomizing drops the temperature of the incoming air ,the moisture in the air can freeze which cuts down the area of the inlet and reduces power at the same time ,Carb icing is not a problem here but in cold countries with altitude as well it is .Carb icing is a serious thing in aircraft .

[Harps18TV]

Thanks for that wightegi, I have heard about aircraft icing but didn`t think it would be a worthwhile addition to a 90cc bike! I assume then that the sensor switches the heaters on/off when required. Presumably then there is no reason why they can`t be removed or a more basic carb fitted - just thinking things over & they may get left alone as long as they are not a problem. I prefer a simple system!