81 GS 550L Carb Upgrade

[Guest]

My 81 GS 550L has the stock Mikuni CV carbs. I would like to upgrade to a better platform of carb, but am unsure of what ones to put on it. Its a weekend rider, no racing.

[tkent02]

Just out of curiosity, if it's a weekend rider, why the upgrade?

[Steve]

Yep, for a weekend rider, it already has the best carbs.

If you are having problems with them, clean them and tune them, you will be surprised at the performance they can offer.

Just to give another perspective, the usual performance upgrade would be larger carbs. The carbs that are on your 550 are the same carbs that are used on the 850, so they are already capable of flowing plenty of air.

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[tkent02]

If you want a performance upgrade, bolt on a 675cc top end. More bang for the buck than anything else. But if you want a beter performance upgrade, trade it for a 550E.

[rstuffle]

Just out of curiosity, if it's a weekend rider, why the upgrade?

Well, I am having troubles getting replacement parts for them and also the replacement components are getting costly... I figured with a newer intake setup, parts would be more readily available and less costly,

[rstuffle]

Yep, for a weekend rider, it already has the best carbs.

If you are having problems with them, clean them and tune them, you will be surprised at the performance they can offer.

Just to give another perspective, the usual performance upgrade would be larger carbs. The carbs that are on your 550 are the same carbs that are used on the 850, so they are already capable of flowing plenty of air.

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That being the case, how do I find out which parts are interchangeable between bikes. I have been a big GM gearhead, but am new to the motorcycle scene.

[tom203]

......but am new to the motorcycle scene.

As Steve said, properly cleaned carbs will offer plenty of performance and as tkent02 hinted, you can go from there. A 650 makes 72 hp from about 41 cubic inch displacement- not shabby for any naturally aspirated motor.

[JTGS850GL]

The carbs on your bike are Mikuni BS32SS carbs and were used on MANY bikes of that era. You can use a resource like Babbitts Suzuki and see what parts are cross referenced from one year to the next. They have good parts fiches and most parts for the carbs are available for purchase right there but many places offer parts for those carbs as well. Agreed that the BS32SS carbs are as much "performance" as you would need with that engine.

[rstuffle]

I have been told, that if the carbs have been removed from the rails, it'll never run right again. I actually have to replace the #3. is there anything I should know?

[JTGS850GL]

Yep, (Que in BikeCliff's welcome greating)

Here's a link to BikeCliff's web site that contains links to MANY usable tutorials and service manuals including the CV carb rebuild manual.

http://members.dslextreme.com/users/bikecliff/

The carb rebuild tutorial is at:

http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

Your specific factory service manual is at:

http://www.mtsac.edu/~cliff/storage/gs/GS550_77-82_all.pdf

Hope that helps.

[rstuffle]

Yep, (Que in BikeCliff's welcome greating)

Here's a link to BikeCliff's web site that contains links to MANY usable tutorials and service manuals including the CV carb rebuild manual.

http://members.dslextreme.com/users/bikecliff/

The carb rebuild tutorial is at:

http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

Your specific factory service manual is at:

http://www.mtsac.edu/~cliff/storage/gs/GS550_77-82_all.pdf

Hope that helps.

Thank you!!!!!!!!!
This is just about everything I could need for my 550!!!!!!!

[rstuffle]

Also, I was thinking of opening up the baffles in the exhaust or changing the mufflers out. I would like it to sound a little louder than it is now. Any suggestions on brand or type.

[Steve]

I just came back to check progress on this thread and was about to offer some help, until I saw this:

Also, I was thinking of opening up the baffles in the exhaust or changing the mufflers out. I would like it to sound a little louder than it is now. Any suggestions on brand or type.

Sorry, but that is where my help (and a few others') ends. We have a hard enough time with the non-motorcycling population, we don't need to aggravate them with more noise.

Yes, that is my opinion, but it is also shared by a few others.

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[rstuffle]

I am not looking for the loud drag bike sound, I am looking for something that sounds a little more throaty.

[Steve]

I am not looking for the loud drag bike sound, I am looking for something that sounds a little more throaty.

No problem. Good luck with your search.

Maybe we might meet at the Brown County Rally in June?

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