Prepping for the valve clearances. I was able to get started last night. You have to peel the onion to get the the valve cover.
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My F650 comes with a pair of BST33's. Those hoses are part of your power jet circuit. It adjusts the mixture for high rpm delivery. I don't want to claim credit as some expert on these, so here is a good article I recently read that does a good job explaining...XS750AU said:Hoping you can help me understand the proper function of the Mikuni BST36SS carbies I am using on my triple. Understand that the YZF uses a different carb, but they appear to be similar.
There are 2 hoses coming off your carbies, just under the diaphragms, I have highlighted in red in the photo.
It appears they would go into the airbox? Do you know what function they perform? Others have suggested that I blank them off, but I would prefer to understand their function before I do that.
XS750AU said:Hoping you can help me understand the proper function of the Mikuni BST36SS carbies I am using on my triple. Understand that the YZF uses a different carb, but they appear to be similar.
There are 2 hoses coming off your carbies, just under the diaphragms, I have highlighted in red in the photo.
It appears they would go into the airbox? Do you know what function they perform? Others have suggested that I blank them off, but I would prefer to understand their function before I do that.
Thanks, that is a great help. I guess the BDST is for the horizontal version of the BST vertical carbi - they look very very similar.they are BDST38's and they do not go to the airbox and are used as bowl breathers.
That is exactly my thoughts, hence the question. I just wanted to know if they needed to vent or pick up a vacuum out of the airbox!Don't block them off. They serve a purpose.
Did you see that link I posted up there in my first comment? That's a write up on these BST carbs and explains all the tubes.XS750AU said:Thanks, that is a great help. I guess the BDST is for the horizontal version of the BST vertical carbi - they look very very similar.
That is exactly my thoughts, hence the question. I just wanted to know if they needed to vent or pick up a vacuum out of the airbox!
Next question - there is one hose coming off the diaphragm cap (black plastic) on one carbie only. The other 2 carbies have the port capped off. It appear to route down through the choke and into the vacuum side of the venturi. Is this for carbi function or is it just supplying vacuum for some other engine control on acceleration?
If it is for carbi function then why are 2 out of 3 carbies capped off?
Thanks for your help.
Sorry missed that!!!Did you see that link I posted up there in my first comment?
XS750AU said:{edited}
Thank you both for your great help. I think I have now worked it out.
I think this is how they work - if I am wrong please let me know.
Canyon - sorry for highjacking you blog, but thanks for your help.
clem said:Is it looking pretty tight in there or do you have some slop?