gr 650 cv carb qs

[Guest]

recently got my gr 650 running again but for some reason the left carby slide is not moving at all anyone had this problem???

[leigh7005]

ok have got that carby working was the throttle slide no visable cracks put in a spare and she cane to life now a few more problems. wont rev just dies was reving with one carb working though

[Steve]

You have the airbox on? Unless you re-jet the carbs, it won't rev much past idle without the airbox attached.

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[leigh7005]

no air box had pods on it prevously just trying to get it running again then i can rip out engine and paint it

[Steve]

OK, "no airbox". Have you re-jetted the carbs?

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[leigh7005]

nope havent jetted

[leigh7005]

also have diffrent mufflers didnt think it would make that much of a diffrence. as soon as you open the throttle it dies and its very hard to start

[Steve]

"Hard to start" could also be valve adjustment. Does it start any easier when the bike is warm? If so, adjust the valves, they are too tight.

Your carbs are sensitive to the quantity and quality of airflow through them. Without an airbox, pods or even velocity stacks, the air entering the carb is just too turbulent. There needs to be a smooth flow of air past the jets to be able to draw the gas into the air stream.

As a 'proof of concept' that is quick and easy, fold a shop rag in half, place it over the inlets of the carbs. (It's nice if you have a helper for this.) Start the bike, it should already be running better. Twist the throttle, see if it responds better. I know it sounds a bit wild, but the baffle caused by the rag smoothes out the airflow just enough to minimize turbulance around the jets. With the rag clamped in place, you can even take the bike around the block to see how it runs, but it's not a good enough system to do any jetting checks.

That addresses the quality of the airflow, now the quantity.

No idea what you have in the way of "different mufflers", but if they are less restrictive (probably louder) than stock, they will allow more air to flow. (Keep in mind that the stock pipes were actually pretty good at being quiet, yet having good flow.) The airbox is usually the biggest restriction in the total air flow system. Removing it allows quite a bit more air to flow, which requires a bit more fuel to be added to keep the air/fuel ratio in the range where it can be burned decently. How much more fuel will depend on what you install for filters, and how much additional air there is.

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[leigh7005]

cheers mate ill try with the rag today and get back. the mufflers are much louder dont like quiet.i just done a valve adjustment 2 days ago also if anyone needs shims i highly recommend Precision Shims Australia 4 Fay Court Croydon Vic 3136 Australia Phone: 03 9723 0199 Fax: 03 9723 2759
Email: chris@precisionshims.com.au i orderd my shims on wednesday arived on the friday. where in stock and cheaper than the wreakers @ $9.90ea + postage