TR6 Topping up cd175 Carbs

[edkap2002]

Can anyone tell me why, when I top up my carbs with oil, the idle RACES (1500)??!! As the oil bleeds or burns out, the idle returns to normal(800). I tried a 90 weight as recommended by university motors but I've given up on that due to the higher idle....Any thoughts...thank you as always...Ed

 

[TR3driver]

Are you perhaps overfilling them? They aren't supposed to be "full", just high enough that you feel some resistance when putting the plunger back in.

 

[edkap2002]

I was filling them to the "ring" but putting in less now...back in the 70's when I owned a modern MGB I used to fill them without a change in idle

 

[TR3driver]

You could also check that the vent is open. I can't recall offhand just where it is on a CD175, but there has to be a passage that vents that area.

 

[edkap2002]

i'm not sure what vent you refer to

 

[Marvin Gruber]

Add just enough oil to feel pressure with plunger cap about 1/4" from top of carb.
Marv

 

[TR3driver]

i'm not sure what vent you refer to

This shows one version (top left "vent" ) https://www.buckeyetriumphs.org/technical/Carbs/CarbsI/Theory.jpg

But I think on the emission versions, it runs through the casting and comes out under the dome. you can see the hole in this shot
https://www.buckeyetriumphs.org/technical/Carbs/CarbsI/Disassembly1.jpg

 

[edkap2002]

This shows one version (top left "vent" ) https://www.buckeyetriumphs.org/technical/Carbs/CarbsI/Theory.jpg

But I think on the emission versions, it runs through the casting and comes out under the dome. you can see the hole in this shot
https://www.buckeyetriumphs.org/technical/Carbs/CarbsI/Disassembly1.jpg

Thanks for the diagrams....I will check that and report back...sound reasonable

 

[edkap2002]

well...cleaned vents on each car....light shine through....raining here so can test drive but idle seems fine in garage ....so far..YEA!