swaping carbs

[Anonymous]

anyone swap new style carbs 1980+ onto 1979 motor ? tony

[earlfor]

Re: swaping carbs

1980 was the year of change to CV type carbs. 1979 had mechanical slide VM carbs. For example, 1979 GS 750E 26 mm VM carbs mounted using a flanged, bolt on boot. 1980 GS 750E 32 mm CV carbs mounted by using a straight cast integral to the cylinder head aluminium tube. Due to different mount styles and different diameters, the carbs cannot be swapped between the years. I believe all GS models made the change in 1980, but I am not positive on that.

Uhhh, that means No, you cannot make that swap.

Earl

anyone swap new style carbs 1980+ onto 1979 motor ? tony

[Anonymous]

Hmm. I'm not sure about the 750's, Earlfor, but the OP didn't specify a bike. Kind of leaves things a little vague.

I know on the 850's the intake style didn't change. There were differences in the choke mechanism, and the throttle system changed from two cables to one. (No return cable on the CV's). If the center - to - center distances between carbs remained the same, a swap wouldn't be impossible. Impractical, maybe.

Since both styles of carb worked just fine originally, the question is: why would you want or need to swap?

[Detman101]

Well, I have one reason the OP may want to swap.
The VM style carbs don't respond well to cracking the throttle open. The CV carbs do it and accellerate very very well.


Dm of mD

[Anonymous]

two reasons 1) the throttle response on my 1980 is much better especially when playing in the mountains
2) I keep having an overflow problem with the old style carbs

[earlfor]

I have to disagree with that. If VM's are balanced correctly and the jetting is correct, throttle response is very crisp. More practice in setting them up will solve those "problems" :-) There is little difference between the response of the VM's on my 750 and the response of the CV's on my 1150.

Earl

Well, I have one reason the OP may want to swap.
The VM style carbs don't respond well to cracking the throttle open. The CV carbs do it and accellerate very very well.


Dm of mD

[earlfor]

1. Throttle response is the same on either. If it is not, you need to find another mechanic.

2. An overflow problem is caused by sticking floats, incorrect float height or leaking float needles. The type of carb has nothing to do with that.

Earl

two reasons 1) the throttle response on my 1980 is much better especially when playing in the mountains
2) I keep having an overflow problem with the old style carbs

[Anonymous]

I would agree with the float problem but the same problem with two totally different sets of carbs I doubt it and not the very same carb on both sets even tried swapping floats and needle and seats and the same carb leaked...throttle response sorry to disagree but the vm carbs are not as responsive as the bs type the only advantage of the vm is you control closing the carbs but their is a distinct lag in shutting down and giving it the gas and when you are flying in the corners you don't need that lag time...thanks for all the responses