cv carbs on a '79 GS1000?

[Anonymous]

does anybody have any thoughts about using a set of cv carbs on a gs1000 in place of the VM26SS carbs with good results? any recommendations on which cv carbs would work the best without too much trouble and not having to make any serious mods to anything else?

Thanks for any help........

Rick

[bgk]

Rick,

If I'm not mistaken, in 1980 the GS1000 G and GL models were equipped with the CV carbs.

The 78/79/80 1000cc 8-valve engines are the same, with the same cylinder spacing and intake port size, so it's logical to expect that you could buy a used set of carbs and intake boots off of a 1980 model, and bolt 'em right up to your 1978. You might need the 1980 throttle cables too, but I'm not sure.

[Hoomgar]

This is what I am doing as we speak Rick. Thread is here and also on my www button below. -->

http://www.thegsresources.com/_forum/viewtopic.php?t=16329

What I can tell you we have found is that the intake ports on the 78/26mm carbed GS is smaller than the ones on the 80 GL which is what we are using. So we are actually going to use the head and jugs off the GL since the bolt paterns are not the same either.

So to answer your question if your 78 head was the same as mine then a pair of cv carbs from a 80 GL will not just bolt on and work due to the port not being large enough. They will line up OK but you will be restricted. You'll either need to get the head and block off the GL as well to go with the carbs or you will have to have the intake ports on your current head honed out. I have pictures of both at home if you would like to see the diff between them? The carbs off the GL we are using are 34mmcv and Joe says they are going to work great for the better flowing head after we port and polish it.

[bgk]

Geez Rick,

I had it right about the 1980 CV carbs, but wrong about the engines being the same.

Thanks to Hoomgar for setting this right.

He saved you from following my well-intentioned, but bad advice!

Maybe I should stick to asking ignorant questions, instead of giving ignorant answers!

[KEITH KRAUSE]

As Hoomgar said, you cannot put the CV carbs on. If you're not happy with the stock carbs, you may want to look for a set of Mikuni 29mm smoothbores. They work very well, especially with pod filters and a good 4-1 pipe. However, parts are getting harder to find for them. I run the stock carbs with a Dynojet kit. I have a 1085 piston kit, K&N pod filters, V&H 4-1 pipe and cams timed at 106 degrees. Runs very strong.

[earlfor]

Mark, I think polishing the intake ports is a bad idea because that will decrease the swirl effect and mixture efficiency. Increasing velocity through the head will increase efficiency and that would require reducing intake port areas rather than increasing them.

Earl

The carbs off the GL we are using are 34mmcv and Joe says they are going to work great for the better flowing head after we port and polish it.

[Hoomgar]

Mark, I think polishing the intake ports is a bad idea because that will decrease the swirl effect and mixture efficiency. Increasing velocity through the head will increase efficiency and that would require reducing intake port areas rather than increasing them.

Earl

The carbs off the GL we are using are 34mmcv and Joe says they are going to work great for the better flowing head after we port and polish it.

Your right Earl, that's what Joe told me too. The problem is the intake boots do not fit on and there would be a big flat wall for the carbs to push into entering the head. Joe said the same thing and that he does not recommend playing around with trying to re-flow the intakes and that was why we went to the GL head and block. I should have made that clear when I posted last time but it didn't all come out right

Thanks