Suzuki SV650(And Others) Carb Balancing

 Multi-Cylinder engines run at their best when the Carburetors/Fuel bodies are 100% balanced.Out-Of-Balance Carburetors/Fuel Bodies are the major cause of vibrations transmitted through the frame and then Handlebars(Also Vibrating/Blurred side Mirrors).This usually leads to premature Hand Fatigue whilst riding.Faulty balance also reduces MPG and smooth power delivery.

This part of Motorcycle Maintenance is often overlooked but is as important as any other IMHO.

Note.It's best if you use a Paddock Stand or a way to keep the bike level if the bike does not have a centre stand.

I  use a Carbtune 2 Carb balancer.It's so easy to use anyone can balance their carbs with it.John(Sean Morgan) sells to anywhere in the World with super-fast delivery.

This is one of the best devices ever made.Total Quality and serviceable and mine is nearly 15 years old and still like new.

Note:The Vacuum pipes used with any Carb Balancer must be of equal length to the Carbs/Fuel bodies otherwise a false balance will occur and they usually require,"Restrictors" in them near to the Carbs.(The Carbtune 2 comes with everything you need and is very easy to use even if you have never balanced Carbs before).

Pliers:Stumpy Crosspoint Screwdriver:SV650 Bendy Plug Spanner/Wrench:Allen keys:Tank Stay:Carb/Brake cleaner:Blue Locktite.

Rear Cylinder

Seat Off:Seat Bolt covers off:Tank up(Tank Steady).

Air filter Box etc off

Take off vacuum pipe on rear Cylinder that controls the Petcock and suck and you will hear the Petcock open.Then bend and nip as per this picture.


Front Cylinder
(I have removed my Horn Bracket and moved my horn to the Front left of my SV650)
Picture Link

Using the Bendy SV650 Plug Spanner/Wrench opposite end (or appropriate Spanner/Wrench) remove the 3 Radiator bolts and move the Radiator forward out of the way so you can access the front Vacuum Spigot and Cap.Use the pliers to gently remove the Plastic cap off the Spigot.Then attach the second Balancer tube.


Now refit the Three Rad bolts so the Rad is secure for now.

I now wrap the tubes once around over the handlebars and down like this(I had refitted the Rad before I used the Balancer with the engine running)



Then engine should be warm and I you can raise the idle speed a little from the 1300 to 1500 Rpm to make it smoother and easier.

Start the engine.

Checking the levels on the Balancer and if they are out use the Small Stumpy Crosspoint Screwdriver to make small adjustments at the Adjuster(Pic 1 just left of middle) and then flick the Throttle and let them settle.Repeat this procedure for as long as it takes until they are exactly level.Even if you get a little frustrated Don't settle for anything less.Correctly balanced @ idle speeds means the Carb/Fuel bodies will be in balance @ ALL rev bands.


Front Cylinder/Carb
Remove Rad bolts and move Rad out-of-the-way

This could be a good time to check your Front Spark plug condition.Clean and re-gap in needed and check resistance of the Plug cap.New they are 5k ohms.Anything over 10k ohms I would replace.I use NGK racing straights
SD05FMB x1 Black or SD05FMR x1 Red.

Remove Front tube and
don't forget to replace the front Vacuum Spigot Cap!!

Replace Rad and  bolts.

Tip:On my Curvy I've removed the Horn bracket and moved my horn to the left front of the bike.This lets me get to the Front plug very easily.

Rear Cylinder/Carb

Remove Clamp from Petcock vacuum tube.

Remove Carb balancer tube from rear spigot and replace Petcock Vacuum tube.

Clean Balance adjuster with Carb/Brake cleaner and then once it's evaporated put a small dab of Blue Loctite on the Screw to secure it.

Once dried lube adjuster/Throttle mechanism with light oil or GT85 PTFE lube or similar.

Refit Air-box and Filter/Tank/Tank bolt covers/Seat etc and make sure everything is secure around the Bike.

Other Pages

1: SV650 Clutch lifter  Servicing(Make getting neutral  easier)

2:SV650(and others) Regulator/Rectifier Mosfet Replacement/Upgrade


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