The U.S. National Highway Traffic Safety Administration has officially posted a recall on the 2013-2014 Suzuki SFV650 and Burgman 650 as well as the 2012-2014 V-Strom 650 to correct a problem with excessive tappet and camshaft wear. The U.S. recall is part of a larger worldwide campaign that, as we previously reported, also affected the GSX1250F, GSF650, GSX650F, GSR750, and the Japan-only Skywave 250 (the country’s local brand name for the Burgman line) and Gladius 400. None of those other models were offered in the U.S. during the model years affected.
According to documents released by the NHTSA, the cylinder head assembly may have become contaminated during the assembly and storage process. Contaminants between the tappets and cams may cause the hardened surface of the tappet to peel. This occurs when the tappet has a convex surface and an inner part with a hardness at the lower end of the design specification range. In those cases, the hard inner portion of the tappet may come into contact with the cam, causing both parts to wear and increasing the tappet clearance. If the tappet clearance becomes too great, it can begin to make an abnormal noise and can cause an engine to stall.
Suzuki was first made aware of a potential problem in June 2013 when it received six reports with similar symptoms from outside the U.S. Suzuki began an investigation but was initially unable to determine the cause.
As further reports came in, Suzuki decided to change the material of the tappets using a material used on other models in February 2014. A couple of months later, Suzuki updated its assembly process, eliminating the use of partition board to separate assembled cylinder heads.
The field reports continued to come in until November 2015 when Suzuki determined the contaminants were from the partition boards used in the old assembly process. Suzuki also determined that the new tappet surface material was strong enough to resist wear from contamination. As of November 2015, Suzuki had received a total of 51 field reports (none came from the U.S.) Suzuki initiated recall procedures on Dec. 11.
Suzuki dealers will inspect recalled models. On units with 2500 miles or more on the odometer, dealers will inspect tappet clearances and replace both the tappets and camshafts if the clearances are greater than specifications. For models with less than 2500 miles, dealers will replace tappets and camshafts even if the tappet clearances because the tappet surfaces may eventually wear with further use.
The recall affects 1,541 SFV650 models, 3,603 V-Strom 650 models and 1,070 Burgman 650 scooters.