Needs Help again with a GS 650 Gl carbs.

[APE_Jeff]

I just bought a Gs 650 GL, and it fires right up with no choke. But if you touch the gas or even think about giving a bit it dies. If you let it warm up a bit you can run it up to about 3000 but no more, and once you back off the gas it drops rpm, then revs to 4200 on its own, I think I have one bad diaphragm. My reason for thinking this is when the bike is running I placed my finger over the diaphragm vacuum port on the carbs, and 3 of them almost shut down the bike, but the forth one did nothing when blocked. I am not sure please help. O yea does anyone have a set of carbs for it?

[Nessism]

Rebuild your carbs and replace the rubber carb boot o-rings. cycleorings.com has an o-ring kit, Z1 Enterprises has gaskets and pilot jet plugs, the rebuild tutorial is on the GSR homepage. Get busy and welcome!

[Charlie G]

Do what he say's. He prodded me a month or so ago to do some "basic matainance". It sounded a bit harsh at the time, but it really needed to be done. It took forever, for me to do, but now I could do a set of carbs or adj. valves, pretty quick. My GS 650 purrs now. Welcome!

cg

[BassCliff]

Greetings and Salutations!!

Hi Mr. APE_Jeff,

I'm just here to day "Howdy" with a (hopefully) informative post.

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[Steve]

Not sure what you are calling the "diaphragm vacuum port" on your carbs, but if you can block anything on the intake side of the carbs while it's running, your problem is that you do not have an airbox installed.

The only vacuum involved in the diaphragms comes from the small hole at the bottom of the slide. If you can reach that and block it while the engine is running, you have fingers that are much smaller than most of ours. And, when you are trying to block that hole, your finger will be blocking the airflow to the carb, and maybe even lifting the slide a bit. Any one of these will affect the way the engine runs. The other small ports in the carb intake are the pilot air jet at the 8 o'clock position and the main air jet at the 4 o'clock position. Neither one of these has anything to do with "diaphragm vacuum" The large port at the top is merely an atmospheric reference for the bottom of the diaphragm and also the air intake for the "choke" circuit. Blocking that should not affect anything, as long as you are not using the "choke".

If you can fire the bike up cold without using the "choke" you have some serious mis-adjustment problems. When everything is adjusted properly, you might have to use just a little, but not having to use any shows that you are probably running far too rich on the pilot circuit. If that is the case, it's no wonder that you are having problems.

Your best bet will be to remove the carbs from the bike, completely strip them down for inspection, clean them THOUROUGHLY (that means a dip, not a spray), and re-assemble them with new o-rings from cycleorings.com.

When you take your diaphragms out, hold them up to the light, stretch them lightly and look for holes. This is what you don't want to see:


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