FAQ

TABLE OF CONTENTS

Here you will find a compilation of tuning help, tech support articles, diagrams and manuals for products we offer. 

Tuning Section

If you purchased one of the performance products from TJ Brutal Customs, LLC, then you will need to tune your machine properly. Any time you change the intake or exhaust on a motor you will need to adjust your fuel and air metering to account for the change in air/exhaust flow. The following applies to The Honda Shadow VT600/VLX, VT750, and VT1100 with CV carbs, non-EFI models.
You will need one of our Performance Tuning Kits to properly tune your bike as our kits are assembled specifically to work with our products. My jet kits are not a "stage" kit as offered by some companies. “Stage” kits typically do not include the necessary components to tune for our products.
Your Performance Tuning Kit will contain Pilot Jets, Main Jets and Shims. If you have a stock jet needle (no notches) You will want to use 2 shims per needle. If you have an aftermarket needle (notches on the needle) you can start at the lowest setting (clip closest to the blunt end of the needle). DO NOT DRILL A HOLE IN YOUR SLIDES!
When installing the jets there is no need to crank them down with much force, a gentle turn to snug them down is all that's required. They are brass so they will break or shear easily.
There is no magic formula to tune a bike, so yes you may need to pull the carburetor several times and make adjustments. If you are at a higher elevation you will most likely want smaller jets, if you are closer to sea level you will want to use larger jets. Start with the smaller jets and work your way up.
If you are replacing your mix screw with our long handled mix screw, make sure that when removing the stock mix screw you pull the screw, a spring, a metal washer and a rubber O-ring out of the port. Install the new mix screw with the new components only.
The diagram below shows you which tuning parts (jets, needle) affect the different throttle stages. Thus if you are having a lean condition at wide open throttle then you may want to increase the size of your main jet.
Begin by tuning your idle to 1/4 throttle, once the bike starts and gets to 1/4 throttle well, move to the next throttle stage. When tuning it is helpful to use a bit of waterproof grease on the inside of the carb boots and the rear port of the carb to make installation and removal easier. You can reference the videos on our YouTube channel TJBRUTALCUSTOMS for more tuning and carb setup tips!

 

How do you know if a bike is running lean or rich? 

Lean Mixture Symptoms

1 - It is difficult to apply the throttle quickly or the engine picks up speed when the throttle is rolled off.
2 - The engine knocks or Pings or overheats. 
3 - The engine surges or hunts for a stable RPM while cruising at part throttle.  
4 - Engine acceleration is flat or slow to pick up. 
5 - When the pilot circuit is too lean, there will be popping or spitting in the carburetor as the throttle is opened. Sometimes there will be popping or after fire in the exhaust on deceleration after the throttle has been closed. 
6 - Engine performance improves in warmer weather, or runs poorly in cold weather.  
7- Engine performance worsens when intake is removed.  
8 - Baked white and flaky spark plugs. 

 Rich Mixture Symptoms

1 - Engine acceleration is flat, uneven, not crisp. 
2 - The throttle needs to be opened continuously to maintain consistent acceleration. 
3 - The engine performs poorly when the weather gets warmer, or the engine works better in cold conditions.  
4 - Black smoke coming out of the exhaust.  
5 - Poor fuel economy. 
6 - Engine performance improves when the intake is removed.  
7 - When the pilot circuit is rich, the engine will idle roughly, or not return to idle without blipping the throttle, the exhaust can smell of excessive fuel and burn the eyes.  
8 - Black sooty or fouled spark plugs, black and sooty exhaust tail pipes. 

 

How do I know which jetting circuit or jet to adjust? 

The image below illustrates which metering circuits govern each throttle stage.
For instance, if you are having an issue in your top end between 3/4 to WOT (4/4) you need to address the main jet, this is a simple diagram to tuning your bike and applies to CV carbs and mechanical carbs found on your Honda Shadow. Honda Shadow Keihin Carburetor Tuning Diagram

Why don't you sell pod/cone/pancake filters?  

Don't use a cone filter. There's a reason I don't sell them to people. I don't offer anything that's half-assed or not good for your bike. No matter how you tune the bike with a cone filter/pod/pancake, you will always have either sub par performance or an issue with one or more throttle stages. The VT600 has a vacuum operated CV carburetor, which means that the slide is operated by the vacuum in the venturi of the carburetor.
For the slide to operate properly the venturi requires a steady negative vacuum, a pod/cone/pancake filter creates a large amount of turbulence right next to the slide, destroying the carbs ability to properly deliver the right amount of metered portions of fuel and air to the motor. On a flow meter bench test, pod filters created a stupid amount of turbulence in the carburetor, whereas a velocity stack succeeded in reducing the turbulence in the venturi making tuning easier and allowing the motor to perform better. The stock intake system is actually designed around a velocity stack principle;  both dual and single carb models because the engineers know this is an effective way of delivering air to a CV carb. Now it bears mentioning that A mechanical carb where the slide is operated by a cable attached to the throttle, a pod filter is less of an issue. Granted, on a mechanical carb a velocity stack does improve performance, but a pod/cone filter will work. The CV carbs on the Honda Shadow line are well made, easy to use and easy to upkeep, requiring minimal knowledge and skill to maintain and upgrade them. If you want to increase your bikes performance and get rid of the fugly stock intake, Pick up a velocity stack/s and a performance jet kit from the site, READ the entire FAQ page and watch my youtube channel tjbrutalcustoms ;) Everything you need is there to get your bike running and tuned properly!

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FAQ

Will Marvel Mystery Oil or Seafoam fix my carb issues?

I am not going to say adding some fluid to your bikes gas or oil will fix a problem. These products are marginal means of preventative medicine/maintenance/preventative steps at best. They should never be used to fix a problem on your bike. If my bike is going to sit for a long time, I drain the gas. Reactive fixes after leaving a bike to sit with fuel in it are rarely if ever a good idea and the issues most likely could have been avoided with proper preparation. When gas is left to sit, it evaporates and leaves behind varnish. Much like cholesterol in veins, it reduces the ID of the passages in your carb and in your jets, even a few thousandths of an inch can change a 125 main jet to something like a 115... which would mean your bike will no longer run properly. If a bike has badly corroded jets,  just replace them.  

 

Why do two coolant lines go to my carburetor? Can I get rid of them? 

Coolant is passed through a small dead end on the single carb Honda shadow. This is done not to cool the carburetors but to heat them. The idea is to prevent the formation of ice in the carburetor throat as fuel is evaporated. Fuel evaporation can cause extreme temperature decreases in the throat of the carburetor. During particularly humid and cool weather conditions such as riding in clouds or fog, ice could form in the carburetors and prevent the engine from running.
That is the theory. In practice this rarely happens. There is also a downside to this carb heating. At upper elevations and at high temperatures, the heating of the carbs can be excessive and actually cause the fuel to boil preventing the engine from running. There have been many reports of this condition arising while I have neither heard of nor experienced any instances of carb icing on the Honda Shadows.
You can remove the coolant lines from your carburetor, just unscrew that little junction and pull it out of your carb. You can then connect the line going from your radiator to the intake manifold or you can plug them. 

 

How do I turn my dual carb bike into a single carb bike?

Do not, I repeat, do not try to turn your dual carb bike into a single carb.
I have seen several bikes become worthless scrap heaps due to people attempting to modify the dual carb shadow. 

  • Two carbs provide a perfect mixture to each cylinder. its the absolute perfect means of fuel delivery for each cylinder. Honda had to go to a single carb only because of EPA regulations and as a result, they lost horsepower, don’t believe me? Just look at the spec sheets for a pre 2000 vlx versus a 2003 vlx. The STOCK numbers even reflect the decrease in performance AND mileage!!!!

  • The only way to turn a dual carb anything into a single carb without harming the motor is this – the carburetor must be equidistant from each cylinder/compression chamber. This would mean you have to put your carb right in the middle of your tank. And this then poses another problem, wind, and distance of intake plenum which ill touch upon later.  Because the intakes are on opposing sides of the cylinders this is the only way to accomplish this without harming your motor.

  • Creating an intake can’t just be done with PVC or pipe fittings or even welded tubing. The interior of an intake manifold or plenum need to have SOME texture to the surface, otherwise fuel will pool up in certain areas. Additionally, you cant have ANY right angles in the intake. This would also cause the emulsion of fuel to be reversed from the throat of the carb and cause large drops of fuel to collect and move into the chamber… no good. Put this to the test, go to a flow bench and pull emulsified fuel through a perfectly smooth bore intake… fuel will pool and you will see large drops being thrown into the cylinder.

  • Going from a dual carb to a single reduces your performance and the aerodynamics of the bike. Why would you want to decrease your bikes ability to perform better?

  • Most of the intakes people attempt to build place the carburetor to the side of the bike. Now think about this. One cylinder is going to be closer to the carb than the other. Wonder why manufacturers of vehicles don’t do this? Because it’s wrong and harmful to the motor and will give you piss poor performance. People design motors and carbs to function the way they were meant to. Sure you can modify and improve sometimes but this isn’t a modification… this is just uneducated foolishness. I don’t care what yahoo built or fabbed his own intake and told you it worked great, do you think he really invested the time in learning air/fuel dynamics for the internal combustion motor? Probably not.

  • When something evaporates it takes heat out of all the stuff around it. When fuel leaves the carburetor venturis it is vaporizing (being ripped into little droplets) but it is also evaporating at the same time (so much more surface area to evaporate from with zillions of little tiny fuel droplets). Because it's evaporating it's drawing that heat needed to do so from everything around it- namely the carburetor and intake manifold.This can drop the temps low enough that when the air is cool and moist it can actually cause water vapor in the air to condense on those (chilled) parts.In really cool, wet weather (below about 45*F) or with the distance between the carb and the intake valve being too long. that condensation can actually FREEZE on those parts after it condenses, thus leaning the mixture out.  When it does so inside the venturis/around the throttle plates in the throat of the carb it's called "carburetor icing" and it can choke the idle down to the point it can actually stall the engine!, ever see tiny beads of water on an intake? This is a non-optimal situation, keeping the intake close to the combustion chamber keeps the temperature warm enough to prevent the formation of ice in the carburetor throat as fuel is evaporated. Fuel evaporation can cause extreme temperature decreases in the throat of the carburetor. During particularly humid and cool weather conditions such as riding in clouds or fog, ice could form in the carburetors and prevent the engine from running properly. That is the theory. In practice this rarely happens. There is a reason the connecting rubber between the carb and the motor is called an “insulator boot” it has insulating properties to avoid this situation.

  • Finally, if you want the look of a single carb bike, get a single carb bike. Don’t attempt to ignore physics and internal combustion dynamics.  

How do you feel about header wrap? 

Anytime you heat up metal you have hydrogen crystallization, its normal. Trapping heat in exhaust can intensify this effect. you are riding a 600cc motorcycle, and if anyone tells you you are going to get better performance from "scavenging effects" or temperature gradients its not something you would notice unless you are trying to shave 1/10 of a second off a 1/4 mile time. Here's the downside of header wrap, the wrap elevates pipe temperatures, promoting cracking, and traps moisture, greatly accelerating corrosion, especially if the bike is operated in hard weather where the pipes and wrap can get soaked down. Now this can well be avoided by wrapping pipes that have been coated with either high temp enamel or whatever ceramic coating you wish to use. HOWEVER, the wrap will STILL trap moisture next to the pipes and this can cause a quicker degradation of whatever coating is on the exhaust.

No exhaust company in the world will honor their warranty if you wrap their exhaust. Old school race teams would wrap their headers to keep engine bay temperatures down, however the headers being run at 200 mph for an extended period of time were toast due to the wrap trapping all that head. Ceramic coatings accomplish this much more efficiently and last longer than a wrap. 

Performance wise, any scavenging effects you might gain from wrap wont ever be really noticeable... its a 600cc motor. Not a race motor. So here's what I would recommend, get the pipes coated, or chromed.  It will greatly prolong the life of the exhaust not from "crystallization" so much as from corrosion. its a smart investment to keep your exhaust looking good for years to come. =)

 

Can the Fuel Pump be removed from my Shadow? 

The "fuel pump" on the dual carb vlx is not even a real fuel pump, it is an automatic shutoff valve to stop the flow of fuel should the bike go down in an accident. the valve opens when the bike is turned on and allows fuel to pass by to the carbs, the best way to run the fuel line from the tank to carbs is to take about 12-14 inches of line and run it in a circle from the petcock circling back around to the carbs, its very easy to install, and allows room for a fuel filter as well. 

Consider this, if the fuel pump was so necessary, why did Honda get rid of it on single carb models? they did and didn't, they replaced the electronic shutoff valve with an Auto Fuel Petcock Valve which is vacuum activated. when the motor is turned on, the vacuum from the motor pulls open the diaphragm and allows fuel to pass through.This design however was recalled on all single carb VT600 models from 2000-2008. 

I have built numerous dual carb bikes and run them all straight to carb, its not so much a gravity feed setup as it operates off the weight of the fuel in the gas tank. so long as your vent tube or cap is vented you will be just fine

 

What do I do about the vent in my rear cylinder (the crankcase breather)? 

Pistons push air and gasses on both ends of the cylinder. Moving anything takes some amount of energy. Pumping pressure out of an engine through a small breather also takes energy, because the breather hole is so restrictive, but it has to be so. 

When crankcase pressure builds because the air and gasses inside can't easily vent, it will escape wherever it can. This is the cause of many small oil leaks. I have had people call me who plugged their breather and they experienced head gasket leaks, oil spouting out of places it shouldn't be,  and poor performance almost immediately. 

To fix this, you have to exhaust the area inside the crankcase, removing the combustion products, which blow by the piston rings. After only a couple of power strokes the case pressure rises. The perfect breather would allow crankcase pressure and blow-by gas to expel while simultaneously providing low pressure inside the crankcase. Honda has designed their crankcase breather to go to a small tank ( the triangular opaque tank) to catch the fuel and such that get past the rings in blow by. You don't need this tank, all you need to do is run a foot or so of hose to the ground from your crankcase breather. You can put a mini filter on it, but it will eventually end up getting clogged and not allow the pressure to vent properly. 

 

How do I wire up your start button and kill switches for my bike?  

I get asked this question all the time so here's a very simple wiring diagram to help you wire up the Kill switch and start button for your VT600 or VT750.  The Blue and White wire in your cluster is part of the headlight cutoff which cuts off power to your headlight when starting, if you want to run a switch to your headlight, use the B/R wire in the 9 pin cluster to supply power to your headlight. 

 

Is it a Bobber or a Chopper???

Since there are many who have come before me and who have addressed this before I will quote a man who is legendary in the motorcycle community, Sugar Bear. In his words -

 "A short bike with a Sportster tank and a flat fender is not a "bobber," it's just a short chop. About 99% of the bikes that are called bobbers...well, you get the picture. I've been involved in conversations with youngsters (born after 1960) who claim that what they build are Bobbers. I'm not even sure most of them have ever seen one.  In the '50's, in my area, we were riding chops, bobbers, and garbage wagons (full dressers or baggers, as they are known now) and each had a distinct style! Chops had cut-down tanks (this is before Sportster tanks were made), cut-down fenders, no floorboards, cut-up bars or apes, usually up-sweeps with fishtails (normally no mufflers), side-mount taillight, etc. Bobbers had small fat-bobs, floorboards, bobbed rear stock fender (usually cut at the rear fender hinge), the stock exhaust (2-into-1), stock bars, basically a cut-down (bobbed) stock bike. Of course we know what a garbage wagon (eh, bagger) looked like. Anyway, you guys are building short chops, not bobbers. This is a cycle that repeats itself time after time. People start building chops, then they build long chops because that's always been considered what a chop should look like. Then after awhile, they begin to realize that the long chops they built are hard to handle and you need gorilla arms to keep it straight and to turn. Of course, these people flunked geometry and physics because they unknowingly set up their bikes wrong. So to be able to get back to riding, they shortened up the bikes but didn't want them to be called chops (because that might seem to infer they don't handle) so they called them bobbers, custom bikes, etc. I've seen this cycle so many times in my riding history that it's ridiculous. I remember people snickering at me in the early '90s because I was riding long chops and still building them. "That looks cool, but I wouldn't ride one of those." "How does that thing handle in the curves (snicker)." It's very easy to tell who the uninformed are. If you don't know how to set up a long bike so you can ride it with one hand and be comfy, buy a stocker, put some chrome and handlebars on it, and stop ruining the reputation of choppers. If you want a chop and don't know how to set up a long one, do a short one. A long chop is a thing of beauty; there's nothing like it. If set up right, you'll ride it forever and smile away every mile. If in doubt, ask anyone who has ridden a Sugar Bear chop. Remember, a short bike with a Sportster tank and a flat fender is not a bobber-it's just a short chop."

 I have aftermarket bars and/or risers. How do I determine what length cables I need? 

We cannot supply a length based on a handle bar description alone. There are just too many variables to account for. For example, positioning the bars differently in the handlebar clamps can affect the length of the cable that is necessary for proper operation.  The best way to proceed is for you to do a full mock up. Leave the stock cables installed on the motor and carburetor or FI system, install the new handlebars to their desired location, and install the controls (throttle/lever) on the new handlebars.  Then determine how much longer the stock cable needs to be (from the housing end) to reach the new location of the throttle or control lever. During this mock-up process you must make sure the new cable length will allow for full movement of the handlebars from lock to lock. Keep in mind that it is easier to absorb an extra inch or two of cable length in routing than it is to make up for a cable that is too short.  So, if there are any doubts, going a little long is usually the safer way to go. Once you have determined how much longer than stock you need, you can review what we currently offer for you model.  If you don’t see the length you need, please contact us at customerservice@shoptjbc.com with the year make and model of your machine and how much longer or shorter then stock you need and we’ll be happy to provide detailed information on your specific needs
Alternately you can use a wire to measure for new cables but this is much less precise and has a larger margin for error. Install your new handlebars on the bike. Run the wire in the desired path that you will want to run the cable. Measure the length of your stock cable.(housing only). Subtract the length of your stock cable from the new measurement that you have made with the wire. The year make and model are important as many different bikes have different amounts of cable feed out at the ends. 

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Can I cut the mufflers of my VT600 or VT750? 

Sure! You can also drop your bike out of a plane from 30k feet! But that doesn't mean its good for your bike! The Honda shadow 600 and 750 exhaust has 2 differently designed header pipes for the forward and rear cylinders. The forward pipe being made of a double wall construction, is only properly supported when the muffler is attached. If you cut off the muffler, you end up having a problem on your hands. The inner pipe will end up tearing itself off of the boss all the way up at the exhaust manifold due to vibration and heat and the tubing's thin wall. Then you have an exhaust flow issue, and this can negatively affect engine performance, leading to exhaust leaks, lean conditions and all sorts of fun stuff. You can't just pull it out of the outer pipe either, because the inner pipe has 2 compound bends. You have to cut off the entire pipe. Most people end up hearing a weird metallic whining, vibrating sound at certain rpms, but can rarely find it. (I know because I had it happen to my bike years ago when I didn't know jack squat. I have encountered it on other riders bikes who had the exact same issue.) It then ends up wearing a hole in the outer pipe, causing more exhaust issues, and leaks. It"s all bad news. The rear pipe doesn't even have a complete outer wall. it merely has a heat shield covering the first 18" or so of exhaust tubing which is barely bigger than an inch. If you cut off the muffler for the rear pipe you are left with a heat shield shaped like a U with a tiny tube in the center. The same vibrational, thin walled tubing issue can happen here. In all honesty the best option for running open exhaust is to get a well made set, it doesn' have to be from me either! There's plenty of companies out there who make exhaust for your bike. And remember any time you change your intake or exhaust setup, you should properly tune to accomodate the new flow changes.

 

 


Shipping

While we cannot be help responsible for items damaged in shipping, if you receive an item that has been damaged in shipping, please visit our contact page, fill out the form with your concern, and we will do everything we can to take care of you. 

There is a three business day processing period of the transaction before the order can begin to be fulfilled. Depending on your purchase, you may experience extended turn around times on custom or made-to-order parts.If you order multiple items and one or more of those items have an extended turn around time, the order will go out once all items have been fulfilled.

We are open Tuesday through Saturday and do shipping on Tuesday, Wednesday, Thursday, and Friday. We are closed on Sunday and Monday, although we always do our best to get back to you via email or phone as soon as possible.   

If you have any questions regarding international shipping or your order status send me an email at customerservice@shoptjbc.com and I will promptly get back to you as soon as possible! 

How to Edit Your Order 

Once you place an order you will see the following screen:


You will then receive an email with your order confirmation which contains important information about your order and shipping. You will have a link in the email to "Edit or Cancel your order click here":

Clicking on the "Edit or Cancel your order click here" link will take you to the following page:

You may either cancel the order (red button) or edit the order (blue button)
Clicking the cancel button will cancel your entire order and you will be issued a refund. 
Clicking the Edit Order button will generate the following popup:

The editing system "cancels" your order to allow you to edit the items in the cart. By clicking continue, you will be taken back to your original cart with all the items you originally ordered (picture below). You can now edit quantities, remove items or add more items to your cart. You may then go through the checkout process and checkout like normal:

 

SERVICE MANUALS

Honda VLX VT600C VT600CD 97-01 Service Manual

Honda VLX VT600 VT600C VT600CD 88-89 91-96 Service Manual

Honda VT750 ACE Service Manual Compressed Part 1

Honda VT750 ACE Service Manual Compressed Part 2


 

WIRING DIAGRAMS

Honda VT600,VLX Wiring Diagram 1988-2007

Honda VT750 ACE Wiring Diagram 1998-2000

Honda VT750 ACE Wiring Diagram 2001-2003 V.1

Honda VT750 ACE Wiring Diagram 2001-2003 V.2

Start Button and Kill Switch Wiring for 2 pole switches

 

MOTOGADGET MANUALS

Motogadget M-Unit Operating and Install Guide

Motogadget M-Switch Mini Manual

Motogadget M-Switch Manual

Motogadget M-Lock Manual

Motogadget M-Flash Manual

 

 VT750 Production Year Reference 

MODEL     YEARS           NAME
VT700C      1984-1987     Shadow 700
VT750C      1998-2000     Shadow 750 ACE
VT750C      2004-2014     Shadow Aero
VT750C2    2007-2014     Shadow Spirit
VT750C2B  2010-2014     Shadow 750 Phantom
VT750C2F  2007-2014     Shadow Spirit
VT750CA    2004-2014      Shadow Aero
VT750CD    1998-2001     Shadow 750 ACE Deluxe
VT750CD2  1998-2001     Shadow 750 ACE Deluxe 2 Tone
VT750CDA  2002-2003     Shadow 750 ACE Deluxe
VT750CDB  2002-2003     Shadow 750 ACE Deluxe
VT750CDC  2002-2003     Shadow 750 ACE Deluxe
VT750CDD  2002-2003     Shadow 750 ACE Deluxe
VT750CS     2004-2014     Shadow Aero
VT750DCA   2001-2009     Shadow Spirit
VT750DCB   2001-2009     Shadow Spirit w/Flames
VT750RS     2010-2013     Shadow RS