Installing Gauges

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Mounting Gauges on the RSV

 

General info

 

The toughest thing about mounting gauges on the Royal Star Venture is finding a place to put them. As there is very little space available, smaller gauges are better. The vast majority of gauges are 2” in diameter or larger, and these do not fit well at all, but if you look long enough, you can find some that are 1 ½ “. JC Whitney sells a triple gauge set this size in black which I used on my 05 RSV, and I have seen other 1 ½” sets in various auto parts stores. O’Reilley Auto Parts sells the very nice iEquus Performance series gauges, and they have a white face 1 ½” triple gauge set at almost the same price as JCW. Unfortunately, you cannot get this set with an ammeter, so I just used the water temp and oil pressure gauges on my 07 RSV. If you want to get adventurous and modify your fairing, a three gauge set will fit nicely where the cassette door is. Just for reference, here are pictures of the dash from both bikes showing several mounting options for the gauges that do not require modifying the bike:

 

 

Once you figure out how to mount the gauges you select, the rest is pretty straight forward. I’ll take them one gauge at a time. But first, here is a picture of the various additional parts to which I’ll refer in the detail:

 

 

Oil Pressure

 

The gauges I used are mechanical gauges, but the process would be essentially identical for electrical sending units. The oil pressure test point on the RSV is a huge 20mm plug on the right side of the engine next to the floor board and right above the header pipe. You will need a 10mm hex key or Allen wrench to remove this plug, and if the bike is on the side stand no oil will escape. While most gauges come with several size adaptors for both SAE and metric engines, none that I have seen have anything this big. The easiest solution is to buy an M20-1.50 oil drain plug at the local auto parts store and drill and tap it for the connection (I got my Oil-Tite! brand plug at the local O’Reilly Auto Parts). You will also need a standard brass “street elbow” in 1/8” male to 1/8” female pipe threads (I bought a Watts A-712 street elbow at Lowes). To complete this modification, drill an 11/32” hole in the center of the plug and use a 1/8x27 NPT tap to cut the threads for the oil line connection. Now wrap the male end of the street elbow with Teflon tape and screw it into the plug. Don’t make it completely tight yet; because, you will want to install the plug into the engine first and then finish tightening the elbow to face forward. Once you have the plug and elbow installed and pointed in the right direction, install the compression fitting used for the oil line into the female end of the elbow. The last thing to do is route the oil line from your gauge down to this plug. Some people like a braded stainless steel oil line, but I just use the small white nylon tubing that comes with the gauge. Although this white tubing is very visible when new, it virtually disappears as soon as you start the engine and it fills with dark oil. You can see in the picture below how I routed it along the wire bundle running up the right side of the frame. Just connect it with the supplied compression fittings at both ends and you are done with the oil pressure gauge.

 

 

Ken Chapin (a.k.a. wuzfuzz) tells me you can buy a plug already drilled and tapped for $16 at www.cycleoneoff.com, but I have not checked this out myself.

 

Water Temperature

 

For the water temperature gauge, you need to be able to mount the sending unit or sensing bulb into the engine water jacket somewhere. Mechanical gauges have a long capillary tube and temperature sensing bulb permanently attached to the gauge, so you have to mount the gauge first and then carefully thread the bulb and capillary tube along the existing water return line to the mounting point for the temp sensor on the top of cylinder number one (left rear cylinder as you sit on the bike). If you remove the spark plug wire on this cylinder you will see a black hex key plug just inside of the spark plug and a little higher. Here is a picture of the cylinder head with the pug installed (but already loose) and then removed:

 

 

And here is a picture of what it is going to look like when you are done:

 

 

This plug has thread sealer on it which makes it quite hard to remove. You will need your 10mm hex key again, and you will probably have to tap on the wrench with a hammer to get the plug turning. There is NO need to remove the spark plug or drain the coolant, but you will need to remove the chrome covers on the head to give you room to get tools to the plug. These are just decorative and come off with the four small hex key bolts you see on top of them.

 

Once the plug is out, you need to get a little creative to mount the temperature sending unit in its place. The plug is 18mm-1.50 threads, and no gauges I have seen come with a metric adaptor this big. Some metric bushing kits may come with an 18mm adaptor, and outside the US it may be easier to find one at an auto parts store. If you can't find one locally, you have three options – either find one to order from the internet (here is one source: http://www.egauges.com/vdo_indA.asp?PN=R7965), buy an 18mm oil drain plug and drill and tap it to the right size to fit your temperature sender, or use this neat little trick to modify an easily available brass fitting from any hardware store:

 

To make an adaptor to fit the water jacket hole, you will need to purchase a brass ½” tube to ½” female pipe adaptor (I got mine at Lowes, Watts part number A-218). In addition, go to your local auto parts store and look for a Help! brand “Spark Plug Non Fouler, 18mm with gasket”, part number 42009. This will only cost about $2.00, and you want the one with the gasket instead of the tapered seat so you can use the gasket when you mount the adaptor into the cylinder head. Now take the ½” tube to ½” female pipe adaptor and take off and discard the nut and tube insert. The threads in the Spark Plug Non Fouler are identical to the threads in the cylinder head, and you will find that the brass adaptor “almost” fits – it will screw about half way into the hole before it binds up, and the steel non-fouler is the perfect tool to use to form the brass threads into the metric size needed. Just put the non-fouler into a vise and use a wrench to force the brass adaptor all the way into the threads, and presto, you have a perfect part! I use the non-fouler to do this so I don’t risk damaging the threads in the engine head while the brass threads of the adaptor are being reshaped to fit. Now all you need to do is select the appropriate ½” adaptor that came with the water temperature gauge and screw it into the metric adaptor you just made, then mount them both into the engine using the spark plug gasket that came with the non-fouler. Here are pictures of using the non-fouler to reshape the threads and the two adaptors screwed together and mounted to the temperature sending unit:

 

 

I have found that the aluminum spark plug gasket that comes with the non-fouler provides an excellent seal for the connection in the cylinder head. The last thing you need to do is make sure the capillary tube is routed exactly as you want it and then mount the temperature bulb to the adaptors you already screwed into the cylinder head. Be very careful to not kink the capillary tube as you work to get it all positioned as you want it, and since you cannot shorten it, you will need to loop the excess and secure it somewhere. Here is a picture of how mine is routed and secured. This particular capillary tube is covered in rubber and looks like a wire harness (others are metal and covered with a spring). You can see mine strapped to the top of the coolant return pipe on the right side of the engine between the carbs and the air box, and the excess tube is looped around twice and secured in the wire strap under the plastic cover on the right side of the steering head:

 

 

Ammeter

 

First, let’s have a little discussion about ammeters. They used to be very common way back when (50s and 60s), but they have just about completely disappeared, replaced by the simple volt meter. Personally, I don’t believe you can tell nearly as much about the condition of the battery AND the charging system from a volt meter alone. Although I prefer to have both ammeter and volt meter, if I have to chose, I would go with the ammeter first. I guess I am just a bit strange. Anyway, hooking up an ammeter presents a bit of a challenge, and I suspect this alone has fueled the switch from ammeter to volt meter in most automotive applications. Whereas a volt meter can simply be connected to any main +12V power source, an ammeter must be connected between the battery and ALL loads. Virtually all automotive ammeters require that they be connected physically in series with the load instead of using a shunt, and this means that a single wire large enough to handle the maximum current draw of the entire vehicle be run from the battery to the ammeter and then back to the main power feeds. To be effective and accurate, the ONLY load that can be connected before the ammeter is the starter motor, and this is just for convenience, as a starter draws so much current it is impractical to connect it after the ammeter. In most applications, you need 10AWG wire for this primary loop to and from the ammeter. 10AWG is big wire, which is not particularly easy to work with.

 

Now lets talk a bit about the specifics of the power circuits in the RSV. The schematic shows the battery power runs through the main fuse then splits into two wires to exit a plug, where the two wires are rejoined into one. The reason for this 1-2-1 configuration is that the pins in the plug cannot handle the full 30 amp load that this main power feed must support, so they need to split that current over two separate pins in the plug. Our ammeter must be connected somewhere between the main fuse and the first connection to any load. The only place to easily tap into this main power feed is at the plug connecting to the main fuse. This is located just behind the primary fuse block under the left side battery cover. To access it you must remove both the battery cover and the left side passenger floor board and then the plastic cover where the passenger floor board is mounted. Here is a picture of the plug connected in its normal position, then unplugged to make the wire modifications easier. All I have done at this point is unstrap the wire retainers to make it a little easier to see the plug.

 

 

The main 30 amp fuse for the bike is on the right side of this plug and the one on the left is a spare (see page 7-32 of the owner’s manual). Disconnecting this plug removes all power to the bike, almost like disconnecting the battery. You can see the two large red wires coming out of the plug – these are the two wires to which I referred above, and this is the easiest place to tap into the circuit to add an ammeter.

 

To connect the ammeter, you will need at least 12 feet of 10 AWG multi-strand wire. I prefer to use two colors, 6 ft of red and 6 feet of black, so that it is easy to distinguish between the wire going from the battery to the ammeter and the one returning from the ammeter. First, slit the tape back a few inches so you can access the wires. Now cut both red wires, being careful to not cut the two other wires in this plug that activate the starter motor. Now solder the red 10 gauge wire to BOTH of the red wires coming out of the plug, and connect the other end of the red wire to the battery side of the ammeter. Solder the black 10 gauge wire to BOTH of the red wires going into the wire bundle, and connect the other end of the black wire to the load side of the ammeter. Besides just connecting the black wire to the wire bundle, I suggest also soldering a 14 gauge wire to the same point for use in connecting any other after-market accessories that you would normally connect directly to the battery. Remember, for the ammeter to work correctly, no other load can be connected to the battery; it must be connected AFTER the ammeter in the circuit, and the only easy way to do this is to add an additional wire like I have described. In the picture below you can see a yellow wire connected with the black wire. This runs up to an in-line 20 amp fuse right in front of the battery (for easy access), and I use this power feed for my horn and driving light relays. This way they do not overload the stock circuits, but any current they draw is shown on the ammeter.

 

 

After soldering the wires together, make sure you insulate them well. In the picture I just have heat-shrink tubing on the joints, but this is not enough, as it is quite thin and easy to tear or rub through with very stiff wires like these. After I took the pictures, I used liquid tape to heavily coat these connections, then re-secured all the wires with the original wire straps.

 

That is all there is to it. Put the bike back together and start enjoying the new gauges and the information they give you about what is really going on with your bike. If you have any questions, feel free to contact me through the VentureRiders forum. Ride Safe!

Kent (Goose) Maurer

Edited March 3, 2009 by V7Goose
added some info