New Guy Needs Help

[Fluffy110]

Hey there everyone,

So I just picked up an 81 GS550L for next to nothing for a cafe racer build. It has 16k on the odometer. I use to build newer race bikes and tune European bikes (Ducati), but I am in unfamiliar territory with carbs.

Here is the dilemma:

-The bike has no airbox, so I'm thinking pod filters may be the best option.
-The mufflers are rusted and corroded, so they have to go. I was thinking about going straight pipe.

I dont know what combination needs what jetting or what you guys would suggest...

Any and all help is welcome...

Thanks,

-Darren

[tom203]

welcome.
Does it start-maybe even idle? CV carbs need to be clean to be happy, whether it's pods or airbox. Open pipes will add to tuning fun. What type of carbs are you familar with?

[kdo58]

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

[sedelen]

Here's you a service manual you can download and save.
There's a chapter for the "L"

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

[Fluffy110]

Thanks for the manual downloads...

Tom - I am carb-tarded. I really don't have a lot of experience with carbs, especially four carb setups. I can tear them down, clean them, and change jets, but as far as tuning them goes, I don't know what I'm doing....

[hampshirehog]

Your best bet is to follow the tutorial to the letter and strip down and clean the carbs and then rebuild with a stage 3 Dynojet kit.

[tom203]

Good confessing- we've all been there and some still are! The attached link is from ninja forum -real basic info attempting to explain how a CV carb works. The Keihin on ninjas is very similar to the suzuki's Mikuni in operation. Getting them running right is straightforward ( MUST be clean)- experts on here can lecture you later on fine tuning

http://faq.ninja250.org/wiki/How_a_carburetor_works:_Carbs_explained

[Fluffy110]

I took the bowls off the carbs tonight. It looks like the main jets have the number 536 or 526 on them. will that run efficient with pod filters and straight pipe or pod filters and cans???

[tkent02]

If you want it a little faster go with a 4-1 pipe and pods. Open pipes suck, and are slow. Spend an hour reading about tuning your carbs and how they work before you mess with anything.

[Fluffy110]

Ok, I did some research and reading, and I think I understand how it works. Correct me if I'm wrong, but I believe I should be able to safely get away with running pod filters if I leave the mufflers alone...

With that said, I have a couple questions.

1-I read the manual, but it didn't show how to run the vacuum, fuel, breather lines. Can someone please send me pictures of how you guys have the lines ran.

2-I am not a fan of paper gaskets, never have been. Personally, my best results with engine work has been with properly laid RTV. Has anyone used RTV on a carb/float bowl?

Thanks again for all of the help...

[loud et]

Read where do these hoses go. http://members.dslextreme.com/users/bikecliff/ it explains all fuel/vent lines.
Everyone just uses paper gaskets on the carb bowls. They can be reused and since you are going to be messing with these carbs a lot right now to get it tuned right, use paper. They are reusable , almost forever.
My plan would be
1- full carb teardown and dip with new o rings from cycle o rings 15$. Berrymans carb dip 18 bucks at wal mart.
2- new carb intake boot o rings from cycle o rings 5$, inspect intake boots and replace if cracked or falling apart. (100$ ish)
3 reassemble carbs with bench sync. There are a number of complete carb rebuild tutorials. Its intimidating at first but actually very very easy. I had never done one before and ust finished my third set.
4 ensure airbox is sealed, aribox boots are soft and in good shape and hooked up right and you have a clean air filter and the weatherstripping on the filter lid is intact.
Do the carbs and get the bike running right with a stock setup before you go messing with jetting. If you have no baseline to adjust from you will never know if your jetting adjustments are all guesswork or logical.
So either get a stock airbox set up or pods and get the bike to run with your newly cleaned carbs....THEN you can have change the exhaust or jetting and know what adjustment you may need to make.
Its a long road to get a gs running right sometimes but you need to follow a logical plan of attack....not just start turning screws and hope for the best.

[hampshirehog]

I am not a fan of paper gaskets, never have been. Personally, my best results with engine work has been with properly laid RTV. Has anyone used RTV on a carb/float bowl?

Don't use RTV on your carbs - the fuel will dissolve it or goops of it will come off and block things.

The paper gaskets on the float bowls aren't used like most other gaskets. They WILL leak fuel if the fuel level gets that high (if the float valves don't work for instance, or the float level is set wrong). The sole purpose of those gaskets is to make a splashproof seal for when the fuel sloshes around in the bowls under braking / acceleration / leaning etc. 99 times out of 100 the old gaskets are ok.

[Fluffy110]

Sounds good...

[Big T]

Ok, I did some research and reading, and I think I understand how it works. Correct me if I'm wrong, but I believe I should be able to safely get away with running pod filters if I leave the mufflers alone...

Thanks again for all of the help...

You should reread that and make sure it pertains to the CV style carb. CV carbs require a proper amount of vacuum to lift their slides (constant velocity), Once you out pods on, you're screwing with Bernoulli's principle and changing the vacuum, which you then chase by rejetting, lifting needles, Dynojet kit, etc.

I'm not saying it can't be done, people do it all the time. I just wouldn't suggest it as a way to learn about carbs, it's a time suck. Simpler to ask down in Parts Wanted or look in Parts for Sale for an airbox. Once you get a stock set up working and understand how your bike should run, then start making changes

It's easier to change the exhaust than the intake with CV carbs

[Sci85]

+1 on Big T's post.