79 GS1000L Carb update

[Guest]

So this topic may have been covered, but I am a newbie here, and I did a search and didn't really come up with any results that would help.....

I am working on my GS1000L project. Carbs on it are just fine (albeit over-jetted, ). I recently tore down a 91 GSXR 1100, and I still have the carbs for it, also in good shape.

I was comparing the two sets, and I was wondering if there was any benefit/drawbacks to converting to the newer carbs on my GS, and if so, how hard it would be. Looking at it, it appears that the intake boots will bolt up to the older head.

Keep in mind I have cables, intakes, and all hardware from both, so I would probably have just about everything to swap, except the 1100 intakes need new boots (cracked), and rejetting.

Just wondering if I could get some input/opinions on this. my search yielded results for 600-800cc bikes, but nothing on the 1 Litre. maybe some feedback from someone who's done it?

So is it worth the trouble? or should I just stick with my current old carbs? Seems like the CV carbs would perform better....

[Steve]

You may want to actually MEASURE the boots. I don't know that particular detail about the GSXR1100, but I'll bet they have carbs bigger than 26mm throats. The '80/'81 8-valve 1000s and 1100s had 34mm carbs, I don't see why the '91 GSXR1100 would be any smaller.

Then, you also need to measure the spacing from side to side. I don't know those numbers, but it would really surprise me if they happened to be the same.

Finally, IF everything did happen to fit and bolt right up, you will need to figure out the jetting. The flow characteristics and jetting requirments are dramatically different between 8-valve and 16-valve engines.

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[ugobug]

Good input. thanks! I did measure the intakes where they bolt to the head, and while the carb spread and intake bore is way different, the bolt pattern of the intake manifolds are the same. so I can bolt the 34mm intakes to the head and the newer carbs would fit.

I'm just trying to find out if there would be any performance/economy/efficiency benefits or drawbacks to using the bigger CV carbs.

[Nessism]

The 1100 carbs may hold a small advantage in making hp, but the hassle in getting them setup would be a big disadvantage.

[Steve]

The bolt pattern might be the same, but there is going to be a LOT of turbulence where those 34mm boots suddenly neck down to the 26mm ports on the head.

Unless you are willing to do a LOT of work opening up the ports (and I have no idea whether it's possible), it sounds like an exercise in futility to me.

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[Big T]

he GSXR carbs would be too big for your bike, mixture wise. It would never run right

[garyS-NJ]

I have a carb set off a '97 katana 600 which I think are BST33SS.. I was thinking about trying these carbs out on my '79 gs1000. I thought I read on here some folks doing same..