SV650: Throttle Position Sensor (TPS) Adjustment

by Stacy on September 5, 2008

I adjusted the Throttle Position Sensor (TPS) on the SV last week. I’ve been meaning to make this adjustment for a few months now, as it’s frequently mentioned in glowing terms on the SVRider forum, and last week’s vacation provided just the free time I needed.

First, a little background — at least, I’ll try to provide a little background despite my status as a newbie wrencher. Here goes. Later model SV650s are fuel injected. The TPS allows fuel to flow when a certain level of RPM is reached. On most SVs, the TPS is set incorrectly and doesn’t allow fuel to flow until it’s too late. In riding terms, this means that the throttle feel on a stock SV is “jerky” at slow speeds: you can ease out on the clutch to start rolling, but when you apply throttle there is a clear jerk at a certain point where you can feel the effects of a sudden rush of fuel into the cylinders. This makes practicing those slow speed u-turns quite the pain.

The original write-up for this adjustment can be found here, and it’s a good one: TPS Mod Step-by-Step Pictorial Guide. I’m not going to reinvent the wheel here, so the only thing I have left to add are some pictures of the location of the Dealer Mode Activator socket on my bike.

Note that I have a 2007 SV650 (naked) non-ABS. Here’s the socket from afar, after removing the passenger seat:

And a closer look:

For those 2007 SV650 owners who have ABS (you lucky dogs!), the DMA socket is located elsewhere. See this thread for details: http://forum.svrider.com/showthread.php?t=72048

Now that I’ve done the adjustment, I think it’s an improvement, but not a revelatory one. You could say that I’m not overwhelmed, but I’m not underwhelmed — so I’m probably just whelmed. (Bonus points if you can name which movie I stole that one from!) Perhaps all that time on the Rebel — which has a very notchy feeling throttle — forced me to learn how to keep a tight reign with the throttle hand.

It’s claimed that a side effect of this adjustment is improved fuel economy. I’ve been keeping track of my gas mileage and I’m curious what the results will be. Time will tell!

Related Posts

{ 2 comments… read them below or add one }

1 jerod May 15, 2009 at 9:20 am

I should’ve posted here that I’m curious about this TPS change…

I do feel like there are times when the throttle seems to … stick? Mainly it’s like when I’m coming to an intersection, I down shift to second, and don’t really need to stop (like when I have a green arrow or something). Instead of a nice roll while I lean into the turn, there’s a gap in power and I try to adjust. It’s very subtle, but it’s moments like this that make rolling on the throttle and having a nice ride into feeling jerky and a little distracted.

It this anything you’ve noticed, and does whelming mean that the throttle is smoother in lower speeds now?

Also, my wife is a big Heath Ledger(sp?) fan. Wasn’t that line out of Ten Things I Hate About You?

2 Stacy May 15, 2009 at 12:35 pm

Hah, good work on ID’ing the source of the quote!

I know exactly what you’re referring to in terms of the throttle being “sticky”. To me, it always felt like a “gap”. After I did the TPS adjustment, it did feel like the gap was less extreme.

In the last couple of weeks, my throttle has started to feel gappy again at lower speeds. I plan to re-check the TPS adjustment to see if anything’s out of whack and adjust as necessary.

Sorry for the long winded answer, but it sounds like this would be worth a try for you. Another alternative is buying an entirely different, high quality, throttle tube with a different profile. Motorcycle Consumer News had a nice write-up a few months ago. I can dig it up if you’re interested.

Leave a Comment