bike carbs on 205
Discussion
I posted this in general gassing but didnt get much response so i was wondering whether any of you guys can help.
I am hopefully going to be fitting some bike carbs to my 205 gti over the summer. I have read quite a bit about bike carb conversions and in general people tend to go for carbs of Yamaha R1 or other 1000cc+ bikes. My question is is there any specific differences between how bike carbs work with repsect to their choke sizes in comparison with other carbs.
The reason for me asking is that I have access to quite a few sets of Yamaha R6 carbs for free, these have 38mm chokes, I was told that these would be too small for my engines and should get R1 carbs as they are 40-42mm I think.
The thing is I was under the impression that as a rule of thumb you tend to go for throttle bodies that are 5mm smaller choke diameter than the equivalent weber as they are that diameter straight through and dont taper to a smaller choke size such as webers.
The carbs I have are 38mm so therefore equivalent to a weber 45, so surely would be able to flow enough air for my engine easily (150-160bhp). This is why i thought that maybe bike carbs work slightly differently and the id isnt comparable to throttle bodies. Also i thought that they must work like SU carbs as they as constant vacuum from what i can see by looking at them.
Cheers
Alex
I am hopefully going to be fitting some bike carbs to my 205 gti over the summer. I have read quite a bit about bike carb conversions and in general people tend to go for carbs of Yamaha R1 or other 1000cc+ bikes. My question is is there any specific differences between how bike carbs work with repsect to their choke sizes in comparison with other carbs.
The reason for me asking is that I have access to quite a few sets of Yamaha R6 carbs for free, these have 38mm chokes, I was told that these would be too small for my engines and should get R1 carbs as they are 40-42mm I think.
The thing is I was under the impression that as a rule of thumb you tend to go for throttle bodies that are 5mm smaller choke diameter than the equivalent weber as they are that diameter straight through and dont taper to a smaller choke size such as webers.
The carbs I have are 38mm so therefore equivalent to a weber 45, so surely would be able to flow enough air for my engine easily (150-160bhp). This is why i thought that maybe bike carbs work slightly differently and the id isnt comparable to throttle bodies. Also i thought that they must work like SU carbs as they as constant vacuum from what i can see by looking at them.
Cheers
Alex
the later R1s are fuel injected (2002 onwards) think thier 43 mm with throttle bodies, sure the earlier ones are similar sized.
a friend reaserched doing this to his 306 but he mentioned something about appaling fuel economy im not sure if its true or not but you might want to look into it first, if you want help finding R1 carbs then let me know.
a friend reaserched doing this to his 306 but he mentioned something about appaling fuel economy im not sure if its true or not but you might want to look into it first, if you want help finding R1 carbs then let me know.
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