Throttle Problems, Buell Problems, and Track Day Questions | Ask the Pro

Answers

By Tim Carrithers, Photography by Factory Pro Tuning

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Finding Fault
I own a 2002 Suzuki DL1000 V-Strom that has a problem with the secondary throttle actuator. It has a Code 28 fault in the ECM. I removed the secondary throttle plates long before this code appeared.At the time it seemed to make the bike run a little better in the 3000-rpm range. I have the Suzuki service manual and it says to check the secondary throttle operation right after turning the key to the On position. It seems to operate normally but the code always comes back. The bike runs OK except that the FI light comes on after running for a few minutes. The bike is completely stock, has been maintained and only has 10,000 miles on it. Have you ever seen this problem before? All of the linkage is still in place so the TPS is still reading and there are no other codes. I have found that only the V-Strom 1000 has the same exact part; all other Suzuki V-twins use this system but have a different type of actuator. Do you know how the ECM controls this actuator? Is it pulsed with a signal? I found no info in the manual. Does the entire throttle body need to be replaced? I plan on installing a Two Brothers exhaust and a Suzuki Teka SFI programmer along with a K&N air filter. Would not having the secondary plates in there cause problems?
Ken Van Horn
Kihei, HI

The C28 code is your ECM's way of saying the secondary throttle-valve actuator-an unassuming little servo-motor -isn't getting voltage or has otherwise gone amiss, so check for a bad connection there. How does the ECM control said actuator? It's pulsed until the throttle position sensor (TPS) reads right. So the first thing to do is make sure your TPS is adjusted correctly. If it doesn't check out, replace it. According to Marc Salvisberg, Internal Combustion Genius and proprietor of Factory Pro Tuning (www.factorypro.com) in San Rafael, California, removing those secondary butterflies can be a good thing if it's done right. Here's why: The secondary butterflies nose over beyond 7000 rpm, obstructing flow and choking power output in the process. But don't remove the whole shaft or you'll get a 29 error code. "If you remove the secondary plates the fuel delivery leans way out between 8000 and 9000 rpm," Salvisberg says. "That's very bad. So you need to retune the stock injection with a mappable device like the Teka SFI Module. Then, once you remove the airbox snorkel, it's a huge improvement." With careful tuning you're talking 8-9 more horsepower at 7000 rpm, with more available above that. So have at it.

Buell Problems
I have a 2007 XB12Scg Lightning. I love everything about the bike except for two problems. The first is it consumes oil. I bought it brand new and it consumed no oil up until my 1000- mile service, when I switched to Syn3 oil. From about 1000 until 5000 miles it consumed two quarts of Syn3 oil. I'm really concerned about this. It was at the dealer for the 5000-mile service and they said they couldn't find any leaks, nor were the plugs showing signs of burning oil. What could possibly be the problem? Is this common with Syn3 oil? If I switch back to petroleum oils will this stop? The second problem is the bike sometimes coughs and backfires through the intake when I am stopped and blip the throttle to pull out. Nothing I've read said anything about Buells having these fuel-injection problems. How can this be fixed?
Tim Baus
Barto, PA

Our rule of thumb for oil consumption is over a quart used in 1000 miles = possible issue. And, unfortunately, depending on how much blipping of the throttle, there could be a cough or backfire. With the Buell fuel-injection system you really don't need to blip at all. The best and only way to address these concerns would be to call customer service and create a file. This way your concerns are noted for future reference. The next step would be to take the bike to a dealer. Tech Service could then work with the dealer to determine if there are any issues with the bike. Without a leakdown/compression test and scan values (or even a test ride by a dealer tech), it is hard to verify an issue.

Sport-Touring Track Days
I am the proud owner of a 2007 Yamaha FJR1300. Although I have been riding for 25 years, this is my first new bike, so I am a little protective of it because I am still making payments. I am not interested in racing, but want to ride track days, maybe take a class and do a little knee-dragging. The FJR is probably not the best choice for the track, so I was thinking about a Kawasaki Ninja 250. They're cheap and I would not mind dropping one. I am a big boy like Mitch Boehm: 6-foot-1 and 235 pounds. Would I be disappointed in the 250?
David Yohe
Richmond, VA

We wouldn't be all that keen on doing track days on an FJR, either-especially if the bank still owns a big chunk of it. And your instincts are solid on the 250 Ninja as well: The revamped '08 version would make an excellent track trainer for someone of smaller stature, but a person your size would be better off on a Ninja 650R. Expect to pay about $4900 for a clean, used '06 model. Or take one large technological step backward to the Ninja 500R and save $1000. Either way, the extra thrust will be worth it.

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