Author Topic: Adding simplicity  (Read 711 times)

Smithy

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Adding simplicity
« on: November 30, 2020, 08:14:24 AM »
Hello knowledgable people

I am building a special out of my other CBF500 and want to make it as simple as possible (like me). One feature it has which I can't decide on is the heating channels in the carbs. There is a take off from the cooling system which routes coolant through the carb bodies to prevent icing.

I used to get carb icing on my XBR500 and it wasn't too troublesome so my question is do I really need this? I don't think it is worth putting back but what do you wise folk reckon?

Ian

themoudie

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Re: Adding simplicity
« Reply #1 on: November 30, 2020, 09:57:35 PM »
Aye Ian,

A thought and only a thought, but if the carbs have been set up weak by the factory for emmission control and we have more ethanol in the fuel, then the carbs will be prone to iceing.

If your special is going to have a non standard air filter and or a less restrictive exhaust, then you will have a greater flow through the engine (cooling effect) and you may have to enrich the mixture to compensate for the increase in flow.

So, if its a fair weather machine or a spring - autumn use machine, you might get away with no warming fluids. But if your going to do winter rallies, you might think otherwise!

I'm just thinking aloud, so have fun with whatever you try.

Good health, Bill

Smithy

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Re: Adding simplicity
« Reply #2 on: December 01, 2020, 02:20:39 PM »
Hi Bill

Thanks for those thoughts, you make a fair point. The bike will most definitely be an all-year-round bike so maybe best to keep the heaters. This for me is the fascination of building something special, you get to think through all kinds of things. I suppose in real terms just connecting up some rubber tubing is hardly too complex. Now moving the battery under the seat hump well that's another story.............

Ian

p.s. progress on this build may appear from time to time in the projects section.

johnr

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Re: Adding simplicity
« Reply #3 on: December 01, 2020, 07:05:58 PM »
quite a few small scooters or step thrus have small electric heaters in the carbs. might be worth seeing if one could be fitted in the carb to take the chill off. the scooter ones are switched by a temp sensor wired into the harness, it just switches the power to the heater off when the sensor gets over 20 degrees ish.

iansoady

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Re: Adding simplicity
« Reply #4 on: December 02, 2020, 02:43:08 PM »
My Honda NX650 had one of those heaters but I was never sure whether it worked. I commuted on the bike all year round including snow & ice*.

What I did find made a difference was Silkolene FST in the petrol although I'm not normally a fan of snake oil.


*Of course, carb icing normally occurs in damp conditions just above freezing.
Ian.
1964 Norton Electra
1969 BSA-Suzuki
1948 BSA C11

Smithy

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Re: Adding simplicity
« Reply #5 on: December 02, 2020, 04:24:49 PM »
Thank you gentlemen for your input. I think when I reassemble the bike is when I shall make my final decision but maybe given that it will be used all year round the heater option makes sense.

Ian