Installing a V.O.E.S. for the Mikuni HSR carburetor

Written by Randy Fox (Randysgym)

Thursday, 11 October 2007

Page 6 of 6

Finishing Up

The only remaining VOES related step, is to attach the vacuum hose that you installed on the carb or manifold during an earlier step. To do this, slide a hose-clamp onto the hose, work the hose onto the nipple of the VOES, and then secure the clamp. See photo below. Note: The hose-clamp is actually optional.

VOES carb connection, Yamaha Road Star

Now just reinstall the gas tank, reconnect the battery, and put the seat back on. That's all there is to it.

The following are unlikely, but they are possible problems this installation might present:

An air leak in the vacuum hose
An air leak at the vacuum fittings
An electrical short.

Check your connections carefully, if you suspect problems.

Start her up and enjoy greater low/mid range power and better gas mileage, as well as full high-RPM power.

Author's Notes

Instead of a VOES, a few riders have installed a MAP (Manifold Air Pressure) sensor, while a few others have adapted the stock TPS to the HSR carburetor.

MAP Sensors: I, personally, have no experience with MAP units. However, as I understand, MAP units supply variable voltage to the ignition system, based on intake vacuum. Sounds good. The difficulty though, is that no MAP unit has been found that will offer voltage outputs on a similar power curve to the stock TPS. Also, there's the issue of the erratic intake vacuum inherent in V-twin engines.

TPS Adapting: Since TPS-adapting requires machining on the carb, not many owners have been willing to take such drastic measures.

A Delphi Road Star Riders forum member (Ken "The Mucker" Sexton), on the East Coast has begun offering a TPS adaptation service. According to The Mucker: Just ship him your HSR carb and the TPS adapter from your stock carb. He will perform his magic, and return your carb with the TPS installed and properly calibrated. The cost of this adaptation--as of this writing--is $100 plus one-way shipping. You can post a message to him on that forum, for further information.

As of this writing, I have found no performance data for these options. In addition, removing the TPS from your stock carb may reduce its resale value, if you decide to sell it.

Unfortunately, I must leave it to the reader to perform a cost/benefit analysis on the real value of VOES vs MAP vs TPS-adaptation. I made my choice…now it’s your turn.

Ride on.

Questions should be asked in our forum (Use discuss link below). The forum is very active and you stand a good chance of getting your questions answered there. If you would like to leave feedback for the author, or have additional information you think will benefit others, please use the comment section at the bottom of this page.

Discuss this article on the forums. (29 posts)

DISCLAIMER: This information and procedure is provided as a courtesy and is for informational purposes only. Neither the publishers nor the authors accept any responsibility for the accuracy, applicability, or suitability of this procedure. You assume all risks associated with the use of this information. NEITHER THE PUBLISHERs NOR THE AUTHORs SHALL IN ANY EVENT BE LIABLE FOR ANY DIRECT, INDIRECT, PUNITIVE, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, OF ANY NATURE ARISING OUT OF OR IN ANY WAY CONNECTED WITH THE USE OR MISUSE OF THIS INFORMATION OR LACK OF INFORMATION. Any type of modification or service work on your motorcycle should always be performed by a professional mechanic. If performed incorrectly, this procedure may endanger the safety of you and others on your motorcycle and possibly invalidate your manufacturer’s warranty.

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Comments (10)

Carb
Written by blkhwn, on 04-09-2015 21:51
I messed around and bought a carb off a buell and dont know if its the same one i'ts an Hsr 42 but I dont know if tis the right one..

HSR42
Written by postie, on 05-15-2014 01:26
Hi from Australia Randy, l'm thinking about fitting a HSR 42 to my 99 RS. Can you tell me is it worth doing, is there a noticeable increase in performance? Should l think about changing the manifold or will the stock one suffice? Apart from the VOES, do l need to make any other adaptions? l have a Barons BAK air cleaner on it now but would like to change it for a smaller one to show the motor a bit more. Can you suggest anything? Hope you can help. Cheers mate.

hmmmmmmmmmmmmmmm
Written by rollerw, on 04-03-2013 15:11
Did anybody come up with an answer for the proper wires to hook up on the newer TPS plugs. My 2000 & 2003 have the black/blue wire but the 2007 has the yellow, solid blue, and solid black wires. I would like to guess it would be the black but want to be sure.

Ron

hmmmmmmmmmmm.......
Written by porkwrice1also, on 07-14-2011 00:34
I have three wires from my stock TPS......1 is yellow....1 is solid blue....and 1 is solid black....not sure which of the two to use to hook up to the VOES, as i don't have a black/blue wire. Any words of widsom on this one?

voes
Written by rollerw, on 01-16-2010 11:14
Any info on dip switch settings when you install the voes? I had to set the Dyna 3000 to full retard before.
Thanks,
Ron

VOES Install
Written by ghost_flamed, on 11-06-2009 09:46
I installed it on my R/S. Saw a little improvement. But is the eng light supposed to go out? Mine seems to stay on? Maybe I need to go back and look at my connections?

VOES and a resistor?
Written by rebel57, on 05-23-2009 05:19
Hi, can I ask you a question? I am very enthusiast after reading your article about installing a VOES on the RS.
I want to do the same.

But my question is, isn’t it necessary to add a resistor (+- 1K) between the VOES and one of the cables?

I’ll hope you can help me.

I’ll drive a 110ci RS with a mikuni HSR 45 and a Dyna 3000 (28B curve), open air filter and exhaust pipe

Greetings Johan (rebel57)

I like it Randy...
Written by Hay Bay Woody, on 08-15-2008 13:40
Hello Randy:
Intake manifold vacuum is far more indicative of engine load conditions than a TPS could ever be. The problem with the TPS is that it cannot retard the spark timing enough for slight increases in throttle. There should be enough of a change in manifold vacuum, with a slight increase in throttle position, to switch the timing to full retard, thus making the Roadstar engine friendlier at low revs. I would consider using a V.O.E.S. in conjunction with the stock TPS, having the V.O.E.S supply full retarding voltage the instant that the vacuum decreases below normal cruising vacuum.
What do you think?

Written by Flashback, on 04-11-2008 08:47
Thanks Randy, the install went great..and I did notice some improvement, not a lot, but noticable..

Written by maessen, on 12-22-2007 19:09
Yes and the Dyna 3000 sees the 5V at WOT as retard mode.

I would reconsider this design and use a MAP sensor instead.

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