Choke

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anyoldiron
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Choke

Post by anyoldiron »

Hello
Finally got a NS400. A question regarding the choke, is it a choke or enriching circuit?

The reason i ask is when the bike is running on the stand and running without choke, (been running for a minute or two) if i apply the choke the rpms rise........................is this usaul, usually i would be looking at jetting

l have never ridden the bike, where it lived before was 2300' lower, bike appears to be stock

THnaks

Mark
Posts: 1352
Joined: Thu Oct 25, 2001 1:01 am
Location: Up Norf

Re: Choke

Post by Mark »

The choke is an enrichment device. It's doesn't restrict the carb venturi in the traditional sense.

Add more fuel to the engine and it spins faster, that's the general idea. :wink: :)

If the engine is still cold, I'd expect an increase in RPM. If it's up to temperature, I'd expect a slight initial rise in engine speed and then for it to fall away again as it will then go rich as no additional air can be drawn through the carbs.

It sounds as though you live in the hills. Typically, an engine will require less fuel the higher you get as the air is less dense. On the flip side, cold air is more dense, so requires more fuel. So maybe a cold day in the mountains may require the same jetting as a warm day at sea level. You can make it really complicated if you want to..

Don't forget that jetting from the factory is designed to suit massive variations in temperatures, humanities and air pressure (altitude) depending on the market that the bike will be sold to. It can't be right everywhere...
If it ain't broke, fix it 'til it is.

anyoldiron
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Re: Choke

Post by anyoldiron »

......................or it could just be a over tired Numpty that forgot to plug the diaphragm vacuum circuit when running off a pony tank.

But thanks Mark, just over tired and over thinking it.

Mark
Posts: 1352
Joined: Thu Oct 25, 2001 1:01 am
Location: Up Norf

Re: Choke

Post by Mark »

A simple fix is always the best. Especially when the "fault" is self inflicted
If it ain't broke, fix it 'til it is.

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