Intake and Exhaust

Shoodaben Engineering Carb Service

To many folks, carburetor work borders on black art and voodoo. Not so at Shoodaben Engineering - and to make you more successful with your carb rebuilds or jet kit installations, I'm offering the following carb service. Your carbs will be disassembled; cleaned; inspected with a magnifier; needle seats polished; bodies reassembled; float levels set; your choice of 2 Minute Mod Jet Kit installed (power or altitude version); pilot air screws set; bench sync of throttle plates; overflow tubes installed; fuel levels confirmed by clear tube method; filled and inspected for leaks; and overflow drain tube system provided. You carbs will be ready for installation when you receive them.

   NOTE this carb service is intended for currently or recently running carbs. If your carbs have sat with fuel in them for years, I can still get them running to perfection, but please be sure to notify me of this when you contact me.As of May 2016, I have done more than 550 sets of zg1000 carburetors, so I've seen almost everything that can possible happen to a set of Concours carbs!

 If your carbs need any  hard parts, that's determined on an as needed basis AFTER the carbs are disassembled, cleaned, and inspected. As of this writing (May 2016 ) there are no carbs newer than 10 years old, so most carbs do need to be kitted. If you want to have Shoodaben Engineering rebuild and upgrade your carbs, email me at and I'll forward an attachment with the info you need. At this point in time, most carbs will need all the services I offer, with a cost of 450.00. The simple fact is these carbs are getting long in the tooth and need these services to give many more years of trouble free service.

2 Minute Mod Jet Kit

It's kind of difficult to put this in words - but of all the innovations I've made with the ZG1000 Concours,  the 2 Minute Mod Jet Kit still impresses and pleases me the most.  Why? Because I broke all the common rules of tuning by restricting the air intake - and making MORE power! This technology won't work on most vehicles, but in this case the airbox is being tuned to the carbs, intake track, cam timing, and exhaust pulses. The result is instant throttle response, no 2000 rpm stutter, greatly improved power, potential for better fuel economy, and a quieter running engine. Jet kits just don't make the kind of power the 2 Minute Mod Jet Kit makes - it's truly impressive!  This is simply the best performance per dollar you can get for the ZG1000.

The 2 Minute Mod Jet Kit is needed when you are installing the Torque Replacement Cams.

 The 2 Minute Mod Jet Kit is available in a power kit for those who really enjoy performance, and an altitude kit which is better for the high altitude (+5000 ft) rider. The 2 Minute Mod Jet Kit comes complete with jets, 2 intake blocks, clear tube for setting fuel level and comprehensive installation and tuning instructions. See the Products and Pricing page for more information.

Overflow Tubes for Absolute Hydrolock Protection

The 1986 to 2006 Concours has gained a reputation for being bulletproof, and rightly so. There is, however, one failure that can render your engine useless with one touch of the starter button - HYDROLOCK. This occurs when the petcock fails to close at the same time a needle valve in carbs fails to seat. It might seem unlikely, but it's generally associated with some dirt or rust in the aging fuel system. The fuel fills a cylinder, and when you attempt to start your bike, the incompressible fuel is met by a fast moving piston, and something has to give - usually a connecting rod. This renders the engine useless and in need of a major teardown to be repaired. $$$$$!

The answer to preventing this problem is surprisingly easy - installing overflow tubes in the fuel bowls. With overflow tubes fitted, any fuel that may flow due to a fuel system failure will be directed out the overflow tubes and the drain system. It doesn't "fix" the fuel issues, but at least it prevents them from turning a fuel system issue into certain engine destruction.

Overflow tubes are nothing new to motorcycle carburetion. They have been factory installed by all the major manufacturers over the years, and even high end Kawasaki models had them into the 2k’s. That said, I think we should look at what’s happening when an overflow tube functions.

Overflow tubes are precision press fit to insure against leakage, and come with a drain line system. You must ship your bowls to Shoodaben Engineering for fitment. See the Products and Pricing page for more information.

NOTE:  First, an overflow tube DOES NOT cause fuel to overflow from the carburetors. This overflowing originates with a petcock and carb fuel needle / seat failure.. When these components fail in an open position, there’s nothing to stop the fuel from flowing from the tank to the carburetor bowls. As the carburetors  overfill, the fuel has to go somewhere; without overflow tubes that fuel will generally first fill a cylinder which creates a hydro lock condition, then the fuel will discharge into the airbox and pour from the airbox onto the engine, and ultimately, to the ground.

 What the overflow tube system DOES is to allow that overflowing fuel to drain out of the carbs through a hose system and go to ground. Now a bit of common sense goes a long way here - there is potential that a pool of fuel can end up under your bike. This potential exists whether or not you have overflow tubes, since the origin comes from the fuel system component failures. Either way,  a fire hazard is an obvious potential, and this should always be a consideration to your safety. Clearly, your bike should not be stored (with or without overflow tubes) near any source of ignition, and if you ever see a pool of fuel under your bike DON’T expose it to ANY source of ignition.

 If you have an overflowing event, clearly there are multiple system failures that need to be addressed. Do not start your bike and service the petcock and carburetors immediately.

Overflow tubes are precision press fit to insure against leakage, and come with a drain line system. You must ship your bowls to Shoodaben Engineering for fitment. See the Products and Pricing page for more information.

 Performance Exhaust Cam Sprocket

The Performance Exhaust Cam Sprocket is a NEW OEM sprocket with the cam mounting holes relocated. This is done to alter the actual camshaft timing, resulting in increased low rpm torque without any loss of top end power. This is a well proven modification, and the low rpm increase is very noticeable. Your bike will accelerate better in the 1000 to 5000 rpm range, resulting in a more linear and tractable power band. The Performance exhaust Cam sprocket was the inspiration for development of the torque cams, but if you are ordering the Torque cams, you do not need the Performance Exhaust Cam Sprocket, as I have the timing points I wanted ground into the Torque Cams already.