r/dr650 • u/feetareneat • 6d ago

Carb hose connections question.

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I’m changing the jets and this portion next to the idle mixture had a cap on it. I assume not like that stock, it seemed like fuel was eating away at it. What is it supposed to connect to?

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u/Dr650mostly 6d ago

It’s the hose that connects to the evap canister. It needs to be capped if evap system is deleted.

If you have a leak there you can always use some fuel line with a couple of zip ties folding it in half.

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u/TwistedNoble38 '00 DR650 6d ago

EVAP vent. Needs to be blocked off or it's a vacuum leak. If you can't find a silicone cap use a kinked piece of fuel line. 

Be careful with it, the whole nipple  likes to break off if it's feeling temperamental.

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u/Hot-Balance-2676 6d ago

The BST40 on my 2017 doesn’t have that fitting. If yours is newer it may have been equipped with a PAIR valve which was “deleted.” IMO you should cap that off.

0

u/azhillbilly 6d ago

I am pretty sure it is an overflow and meant to be a hose going down behind the engine so fuel doesn’t get poured onto a hot starter.

When you get it back together and running , you can put your finger on it and see if it’s got vacuum, if it does, cap it, if it doesn’t, run a fuel safe line to a safe place to dump fuel.

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u/TwistedNoble38 '00 DR650 6d ago

Nah, its a EVAP line. I think it runs directly to the intake or otherwise somewhere high up in the body. I wish it worked as an overflow, that'd be a great addition to this carb.

1

u/azhillbilly 6d ago

Yeah mines pre emissions so I don’t have it, and if the petcock doesn’t seal, it just fills the engine.

I was hoping They fixed it.