Surgin on steady throttle - Page 3 - SV650.org

13-06-06, 07:52 PM

You wont upset the balance of the carbs by simply removing them. As for the choke plungers, I would suggest that if you are going to dismantle them to check them, then the only real way of doing this, IS to remove the carbs. The screws that you attempted to undo are made of Swiss cheese and I can bet that if you try to do this in situ, you will more than likely sheer the screwdriver thread.

I would suggest taking the carbs off and using an impact driver on the threads as soon as you think the heads threads are going to sheer.

johnnyrod · 14-06-06, 11:37 AM

Yep, agree with the Ape. As for fiddling with the needles, that is not good advice. If you haven't changed the exhaust or air filter then moving the needles won't help any, and if you wanted to richen the midrange you'd be wanting to lift the needles not drop them.

14-06-06, 01:03 PM

ooops!

yup, you are correct, you lift the needles by dropping the clip/washer down to the bottom slot.
I did it with mine and it is an easy job once you have taken the side fairings off, if it is a model without the fairing it is really easy.
You can download the pictures of how to remove carbs if you look for
HOW-TO De-restrict SV650 carb bikes with Suzuki kit
in this forum with written instuctions as well. Or look through the old forum files for all the original faults with the carb model from "99 to "03
This did cure the surging on mine, and it is a well documented problem.
But if it has only just started then you may well have to look for choke probs or air leaks or fueling probs, even duff sparkplugs etc.

14-06-06, 01:04 PM

should have added date to make it easy for others,,

Post subject: HOW-TO De-restrict SV650 carb bikes with Suzuki kit

Posted: Wed Jul 20, 2005 10:23 pm

johnnyrod · 14-06-06, 02:32 PM

Don't know if you're referring to the 33bhp kit, I don't know anything about that. Some of the earlier bikes, especially when people tinkered with the exhausts or air filters, ran lean in the midrange. The cure was shimming the carb needles (on the US models there was only one groove), which meant taking the needle out of each carb, moving the washer from the top to the underside of the clip, and putting it back together. This is the equivalent of about half a groove of adjustment. On a stock bike UK though I doubt it makes any odds, certainly didn't on mine though sounds like you had a problem with yours. On a bike with a new can and filter it would mean you were still running lean at the top end.

14-06-06, 05:16 PM

bike was standard when needles were adjusted to bottom slot to stop surging at cruise, but bike has also been restricted now so son can ride it.

14-06-06, 05:29 PM

also up to 2002, lots of the bikes had this particular problem of surging when cruising, weird thing though is that there were some bikes that didn't suffer it at all.
Whether it has a restictor kit or not though shoudn't really make any difference when its cruising as a restrictor kit should only affect hard acceleration and top speed as such, thats as far as I am aware though someone may care to disagree.
As for changing exhaust or air filter then yes that could make it run leaner and cause problems, but fitting a restrictor kit should not affect mixture as it only controls the speed and height at which carb piston rises which but picture link is just to show how anyone can fiddle with carbs

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13-06-06, 07:52 PM	#21
Stig Guest Posts: n/a	You wont upset the balance of the carbs by simply removing them. As for the choke plungers, I would suggest that if you are going to dismantle them to check them, then the only real way of doing this, IS to remove the carbs. The screws that you attempted to undo are made of Swiss cheese and I can bet that if you try to do this in situ, you will more than likely sheer the screwdriver thread. I would suggest taking the carbs off and using an impact driver on the threads as soon as you think the heads threads are going to sheer.

14-06-06, 11:37 AM	#22
johnnyrod Member Mega Poster Join Date: Jul 2003 Location: Doncaster, oop norf Posts: 2,128	Yep, agree with the Ape. As for fiddling with the needles, that is not good advice. If you haven't changed the exhaust or air filter then moving the needles won't help any, and if you wanted to richen the midrange you'd be wanting to lift the needles not drop them.

14-06-06, 01:03 PM	#23
Chatterbox Guest Posts: n/a	ooops! yup, you are correct, you lift the needles by dropping the clip/washer down to the bottom slot. I did it with mine and it is an easy job once you have taken the side fairings off, if it is a model without the fairing it is really easy. You can download the pictures of how to remove carbs if you look for HOW-TO De-restrict SV650 carb bikes with Suzuki kit in this forum with written instuctions as well. Or look through the old forum files for all the original faults with the carb model from "99 to "03 This did cure the surging on mine, and it is a well documented problem. But if it has only just started then you may well have to look for choke probs or air leaks or fueling probs, even duff sparkplugs etc.

14-06-06, 01:04 PM	#24
Chatterbox Guest Posts: n/a	should have added date to make it easy for others,, Post subject: HOW-TO De-restrict SV650 carb bikes with Suzuki kit Posted: Wed Jul 20, 2005 10:23 pm

14-06-06, 02:32 PM	#25
johnnyrod Member Mega Poster Join Date: Jul 2003 Location: Doncaster, oop norf Posts: 2,128	Don't know if you're referring to the 33bhp kit, I don't know anything about that. Some of the earlier bikes, especially when people tinkered with the exhausts or air filters, ran lean in the midrange. The cure was shimming the carb needles (on the US models there was only one groove), which meant taking the needle out of each carb, moving the washer from the top to the underside of the clip, and putting it back together. This is the equivalent of about half a groove of adjustment. On a stock bike UK though I doubt it makes any odds, certainly didn't on mine though sounds like you had a problem with yours. On a bike with a new can and filter it would mean you were still running lean at the top end.

14-06-06, 05:16 PM	#26
Chatterbox Guest Posts: n/a	bike was standard when needles were adjusted to bottom slot to stop surging at cruise, but bike has also been restricted now so son can ride it.

14-06-06, 05:29 PM	#27
Chatterbox Guest Posts: n/a	also up to 2002, lots of the bikes had this particular problem of surging when cruising, weird thing though is that there were some bikes that didn't suffer it at all. Whether it has a restictor kit or not though shoudn't really make any difference when its cruising as a restrictor kit should only affect hard acceleration and top speed as such, thats as far as I am aware though someone may care to disagree. As for changing exhaust or air filter then yes that could make it run leaner and cause problems, but fitting a restrictor kit should not affect mixture as it only controls the speed and height at which carb piston rises which but picture link is just to show how anyone can fiddle with carbs