Balancing your carbs - SV650.org

Sir Trev · 06-08-05, 01:49 PM

Last time I had Dusty my curvey dealer serviced it felt absolutely fantastic as I rode home, it flew with great throttle response and pickup. Since then, and certainly recently, things have been a lot worse, with lumpy running and poor response. So I bought a set of Morgan Carbtune II and this morning hooked them up (after swearing a lot at getting the front pickup attached). The finishing touch to my own servicing found the balances way out. A few minutes of tweaking and - done.

FLIP, WHAT A DIFFERENCE!!!!!!!!! I just got back from my first post-tune run and whooooosh.

If a mecahnically cack-handed office jockey like me can do it, anyone can. Get out there and do it!

Spanner Man · 06-08-05, 02:48 PM

Nice one Trev!
Morgans are well worth the dosh indeed!
You need loooonnnngggg pliers to get the cap off the front pot, & a spare incase it splits!

Cheers

Sid Squid · 06-08-05, 07:54 PM

For your future ease of balancing, remove the front take off cap and instead fit a length of tubing to the stub about 4-5" long, plug the end with a suitable screw or bolt, lead the tube up above the airbox on the right hand front frame tube - near where the bunch of electrical connectors are - when balancing connect the guage tube to that instead, this relieves you of the necessity to faff about down at the front carb when balancing.

06-08-05, 07:56 PM

Quote:

Originally Posted by Sid Squid

For your future ease of balancing, remove the front take off cap and instead fit a length of tubing to the stub about 4-5" long, plug the end with a suitable screw or bolt, lead the tube up above the airbox on the right hand front frame tube - near where the bunch of electrical connectors are - when balancing connect the guage tube to that instead, this relieves you of the necessity to faff about down at the front carb when balancing.

S'wot I did!

Carb balancing is now a piece of the proverbial.

Sir Trev · 07-08-05, 08:20 AM

I will probably do something like that at some point too. Hunting round the FAQ section on the main site has a similar one with copper piping but a length of vacuum hose and one of the restrictor tubes from the Morgan as a sleeve for the stock blanking plug on the end should do just as well.

Out of curiosity, my Haynes told me to remove the air filter housing first. I read that as take the airbox off, which I did (easier than I thought it would be). Do you guys do the same, just take out the filter, or leave everything in place??

Sid Squid · 07-08-05, 02:47 PM

It's possible, but a little awkward, to reach the adjuster screw with the airbox in place. What I normally do with an SV that has the tube fitted is check the balance with the airbox on, and only remove it if an adjustment is needed.

Sir Trev · 07-08-05, 04:13 PM

Thanks for that Sid. I found that I could not quite get to the screws that hold the crankcase breather tube* chamber thingy by the adjuster screw so took the whole airbox off. Easy enough so no big deal, especially as I don't intend to balance the things every other weekend or anything.

After an extended run out this morning I am still grinning about the improvement in pick-up by the way...

Quiff Wichard · 07-08-05, 10:47 PM

i feel like mine needs this doin..

she just isnt as peachy sweet !!

dues a 7K service- can i ask them to do it for me?
or am i best doin it meself and learnin for the future.

ignorance where mechanics r concerned so can I ask>>?? what maked em go outta sync in the first place please???? and how often does it happen then?

and- if they outta sync.wots the symptoms?

Sir Trev · 08-08-05, 07:10 AM

The adjuster screw has no locknut on it and relys on the spring cage it's in to hold it where you leave it. Because of the odd angle and it's daft positioning relative to the fram rails I used a 2.5cm long screwdriver drill bit to make the tweaks. It needed no proessure and turned easily. Because of that it's going to vibrate itself out of true after a while.

Symptoms are a more snatchy pick-up, spluttering at low revs, increased vibration, tendency to stall more often, decreased get-up-and-go. It should be done at a full service service if you take it to a dealer but ask to make sure it's covered - they may of course add it on with 30-45 minutes extra time charged though. Getting the gauges on is the fiddly bit, taking the airbox off not too difficult and balancing them is the easy bit, with just one screw to turn.

Quiff Wichard · 08-08-05, 01:21 PM

cheers Trev

sorry SIR Trev

06-08-05, 01:49 PM	#1
Sir Trev Member Mega Poster Join Date: Jun 2005 Location: High Wycombe, where the chair factories used to be Posts: 1,465	Balancing your carbs Last time I had Dusty my curvey dealer serviced it felt absolutely fantastic as I rode home, it flew with great throttle response and pickup. Since then, and certainly recently, things have been a lot worse, with lumpy running and poor response. So I bought a set of Morgan Carbtune II and this morning hooked them up (after swearing a lot at getting the front pickup attached). The finishing touch to my own servicing found the balances way out. A few minutes of tweaking and - done. FLIP, WHAT A DIFFERENCE!!!!!!!!! I just got back from my first post-tune run and whooooosh. If a mecahnically cack-handed office jockey like me can do it, anyone can. Get out there and do it! __________________ We are the Goon Squad and we're coming to town, BEEP BEEP!

06-08-05, 02:48 PM	#2
Spanner Man Member Mega Poster Join Date: May 2005 Location: Sunbury Middlesex Posts: 1,396	Nice one Trev! Morgans are well worth the dosh indeed! You need loooonnnngggg pliers to get the cap off the front pot, & a spare incase it splits! Cheers __________________ Spanner Man http://stewarts-motorcycles.co.uk/default.html

06-08-05, 07:54 PM	#3
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	For your future ease of balancing, remove the front take off cap and instead fit a length of tubing to the stub about 4-5" long, plug the end with a suitable screw or bolt, lead the tube up above the airbox on the right hand front frame tube - near where the bunch of electrical connectors are - when balancing connect the guage tube to that instead, this relieves you of the necessity to faff about down at the front carb when balancing. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

07-08-05, 08:20 AM	#5
Sir Trev Member Mega Poster Join Date: Jun 2005 Location: High Wycombe, where the chair factories used to be Posts: 1,465	I will probably do something like that at some point too. Hunting round the FAQ section on the main site has a similar one with copper piping but a length of vacuum hose and one of the restrictor tubes from the Morgan as a sleeve for the stock blanking plug on the end should do just as well. Out of curiosity, my Haynes told me to remove the air filter housing first. I read that as take the airbox off, which I did (easier than I thought it would be). Do you guys do the same, just take out the filter, or leave everything in place?? __________________ We are the Goon Squad and we're coming to town, BEEP BEEP!

07-08-05, 02:47 PM	#6
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	It's possible, but a little awkward, to reach the adjuster screw with the airbox in place. What I normally do with an SV that has the tube fitted is check the balance with the airbox on, and only remove it if an adjustment is needed. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

07-08-05, 04:13 PM	#7
Sir Trev Member Mega Poster Join Date: Jun 2005 Location: High Wycombe, where the chair factories used to be Posts: 1,465	Thanks for that Sid. I found that I could not quite get to the screws that hold the crankcase breather tube* chamber thingy by the adjuster screw so took the whole airbox off. Easy enough so no big deal, especially as I don't intend to balance the things every other weekend or anything. After an extended run out this morning I am still grinning about the improvement in pick-up by the way... __________________ We are the Goon Squad and we're coming to town, BEEP BEEP!

07-08-05, 10:47 PM	#8
Quiff Wichard Member Mega Poster Join Date: Aug 2004 Posts: 4,864	i feel like mine needs this doin.. she just isnt as peachy sweet !! dues a 7K service- can i ask them to do it for me? or am i best doin it meself and learnin for the future. ignorance where mechanics r concerned so can I ask>>?? what maked em go outta sync in the first place please???? and how often does it happen then? and- if they outta sync.wots the symptoms? __________________ ooops I did it again ... new bike . cb1000r

08-08-05, 07:10 AM	#9
Sir Trev Member Mega Poster Join Date: Jun 2005 Location: High Wycombe, where the chair factories used to be Posts: 1,465	The adjuster screw has no locknut on it and relys on the spring cage it's in to hold it where you leave it. Because of the odd angle and it's daft positioning relative to the fram rails I used a 2.5cm long screwdriver drill bit to make the tweaks. It needed no proessure and turned easily. Because of that it's going to vibrate itself out of true after a while. Symptoms are a more snatchy pick-up, spluttering at low revs, increased vibration, tendency to stall more often, decreased get-up-and-go. It should be done at a full service service if you take it to a dealer but ask to make sure it's covered - they may of course add it on with 30-45 minutes extra time charged though. Getting the gauges on is the fiddly bit, taking the airbox off not too difficult and balancing them is the easy bit, with just one screw to turn. __________________ We are the Goon Squad and we're coming to town, BEEP BEEP!

08-08-05, 01:21 PM	#10
Quiff Wichard Member Mega Poster Join Date: Aug 2004 Posts: 4,864	cheers Trev sorry SIR Trev __________________ ooops I did it again ... new bike . cb1000r

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Carb balancing by ear?	ikb	SV Talk, Tuning & Tweaking	16	31-01-08 12:28 PM
Carb Balancing	Tris	SV Talk, Tuning & Tweaking	9	09-08-07 09:47 AM
Balancing Carbs/Throttle bodies	tomjones2	Bikes - Talk & Issues	6	06-07-07 10:07 AM
Replacing the Carbs - easy Job? need balancing ?	SpankyHam	SV Talk, Tuning & Tweaking	8	30-06-06 05:42 PM
Applying vacuum to the fuel tap for balancing carbs?	kciN	SV Talk, Tuning & Tweaking	10	16-05-06 03:27 PM