Shop Talk | Tech Questions & Answers

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ABS—Not

I have a 2011 Victory Vision, which comes standard with ABS brakes. It also has “linked” brakes, where the rear brakes are linked to one of the three “pots’ on the front disks. With the bike having about 4000 miles on it, I found myself leading a group of three other riders. As I approached a traffic light, it changed from green to yellow. I could have made it through the intersection, but the rest of the group couldn’t, so I grabbed a handful of brake and came to a stop. I knew the ABS was working because I could feel the pulsing in the lever.

Several hundred miles later, the ABS light came on, indicating a malfunction. I tried a “hard” stop and felt no pulsing, so I knew the ABS wasn’t working. A trip to the dealer resulted in a replaced front wheel sensor. After about 75 miles, it too malfunctioned. Another trip to the dealer, and it was concluded that the air gap between the sensor and “exciter” was a bit wide of the tolerance. Some refitting by the tech and the problem seemed to be solved—no more ABS light. However, now when I grab the brakes, there is no pulsing in the front brake lever. I have braked hard enough to cause the front tire to howl— not lock up, but howl. How do I know if my ABS is functioning properly? If I grab it hard enough to lock the front wheel and it doesn’t work, I’ll likely crash. In fact, I pulled into a service station, ran across some sand at a low speed, and did lock the front wheel. I wasn’t going fast enough to crash, but it was disconcerting.

Bottom line question, is there any way to “test” the ABS without running the risk of crashing? A second question is—if the air gap is a bit wide, would it cause a false indication that would engage the ABS when in fact it wasn’t needed or would you just get a malfunction light?

Blaine McCormick
Via email

_Blaine, typically there are several indications that the ABS is working. First, upon start up, there should be all that annoying whirring and clicking going on as the unit self-tests itself. Second, there is the indicator light itself. It should come on with the key, which lets you know it’s working, and then go out after the system self-tests. If it doesn’t come on at all or stays on there is a malfunction that needs to be addressed. Thirdly, you can use a diagnostic computer or scan tool to interrogate the ABS and make sure it’s working. There is also a fourth way, which is to try to engage the brakes hard enough to slide the wheels, but that’s risky, and not a method I’d recommend.

As to why your ABS didn’t engage when pulling into the gas station, I can’t say for certain, but many systems do shut off below a certain threshold speed, which is usually about ten miles per hour. At those slow speeds, the ABS just can’t cycle fast enough to prevent wheel lock up so if you hit the sand at very low speed the system reacted normally.

Lastly, I doubt very much that an overly large air gap would cause the ABS to become more sensitive; in fact, if it was large enough to light the ABS lamp, the system should have shut off completely and reverted to non-ABS operation. _

Plugs for Poland

I’m the owner of 2007 VT750 Shadow Aero—bought in the USA. Now I would like to exchange the spark plug, but in the shop, they are asking me—is this a C2? C4? RC?

Can you please help me get correct model number?

Pawe Smyka
Warszawa, Polska

_Pawe, if you can send me the VIN number, I can tell you exactly what model you have. However, all of the 2007 Honda VT750s take the same spark plug. The NGK DPR6 EA9 is the standard plug, the DPR7 EA9 the colder alternative. Use them or the equivalent and you shouldn’t have any problems. _

Lifter Lowdown

First, let me say I love getting my subscription every month and turning to your section. I can really relate to your writing.

I recently read an article that mentioned which manufacturers offer automatic hydraulically adjusted valves. I am assuming this is in lieu of having to pay to have them adjusted at periodic maintenance schedules.

I’ve Googled this to no end, and would appreciate you letting me know which manufacturers offer these upgrades and when they started. I have a Yamaha Stratoliner and the cost at the 16,000-mile mark to check and adjust valves is significant. I understand this isn’t necessary in other bikes and is not necessary for Harleys manufactured over the past few years.

Thanks in advance for your help.

Michael Donald  
Via email

Where cruisers are concerned Michael, it’d probably be easier to make a list of manufacturers that don’t offer hydraulic lifters. HD has been using them since 1953 or so, and Honda, Suzuki and Kawasaki use them on certain models. In fact, your Stratoliner also uses hydraulic lifters; however, because each lifter operates two valves, which (along with their associated components) wear at slightly different rates, one rocker arm incorporates a screw type adjuster, which allows you to “balance” the clearance.

Shop Talk | Tech Questions & Answers