EricGorr
Super Power AssClown
- Aug 24, 2000
- 708
- 1
KTM Safety Notice
As a proud owner of four KTM motorcycles it upsets me to write this letter to other “KTM Guys” because I feel the responsibility of informing people about a potential safety hazard with a motorcycle is that of the manufacturer and the management of the American importer/distributor. I don’t like playing the watchdog role but I’ve carefully examined several damaged motorcycles, ordered replacement parts, examined new parts, and performed repairs before I wrote this letter to inform KTM 400/520 owners of what I conclude as a potential hazard that can cause personal injury to the rider and or cost several hundred dollars to repair.
The valve springs on these motorcycles are prone to cracking on the bottom coil, which can cause a catastrophic valve train failure, and in the most extreme circumstance, enabling the valves to contact the piston causing the engine to stop abruptly. KTM has revised the spring design switching from a two-spring set to a single conical spring design.
Recently I ordered the new parts for a customer whose engine I am repairing. The new spring part number is 594.36.028.044 and it is relatively inexpensive. The problem is it doesn’t fit the new cylinder heads that KTM is shipping to customers. The recess for the spring seat in the cylinder head is approximately 2mm smaller than the bottom spring seat washer. And it isn’t apparent to the untrained observer so it is possible to install the new spring kit in the heads that KTM is currently shipping from parts stock, and onto older cylinder heads. The spring seat washer will soon fail causing the same valve train problem as the earlier two-spring design. I had to make a modification to the new head that I recently purchased from KTM that involved boring the spring seat recess in the head to a larger diameter. Not a problem for me, a performance machinist with a vertical mill and several boring tools, but a big problem for the average guy who expects that the parts will fit correctly. What’s worse is that there was no written communication in either parts box warning that the head would need to be modified to fit the new spring.
If you own a KTM 400 or 520 I suggest that you have your local dealer modify the head for the new conical valve springs and install the new parts with fresh stem seals. If you’ve been riding the bike for a few seasons it’s about time that the head was checked for routine maintenance like the condition of the valves, guides, seats and stem seals. If your engine fails there is no warranty or recall that I know of.
One final note, in September of 2002 I attended a national product liability conference at the University of Wisconsin/Madison and there were representatives from some American motorcycle manufacturers. One of the points covered concerned recalls and warnings. The theme expressed by the speakers was that honesty is the best policy. In my opinion profiting from a design flaw is inexcusable. In the near future I hope to see the management of KTM in America straighten out this debacle by sending technical communications to dealers and owners warning of this potential problem, labeling cylinder heads that require machining to accept the larger diameter spring seat washers or pull them from stock, and providing detailed instructions on exactly how to repair bikes that are currently in use.
Eric Gorr, a happy owner of a KTM 640 Adventure
As a proud owner of four KTM motorcycles it upsets me to write this letter to other “KTM Guys” because I feel the responsibility of informing people about a potential safety hazard with a motorcycle is that of the manufacturer and the management of the American importer/distributor. I don’t like playing the watchdog role but I’ve carefully examined several damaged motorcycles, ordered replacement parts, examined new parts, and performed repairs before I wrote this letter to inform KTM 400/520 owners of what I conclude as a potential hazard that can cause personal injury to the rider and or cost several hundred dollars to repair.
The valve springs on these motorcycles are prone to cracking on the bottom coil, which can cause a catastrophic valve train failure, and in the most extreme circumstance, enabling the valves to contact the piston causing the engine to stop abruptly. KTM has revised the spring design switching from a two-spring set to a single conical spring design.
Recently I ordered the new parts for a customer whose engine I am repairing. The new spring part number is 594.36.028.044 and it is relatively inexpensive. The problem is it doesn’t fit the new cylinder heads that KTM is shipping to customers. The recess for the spring seat in the cylinder head is approximately 2mm smaller than the bottom spring seat washer. And it isn’t apparent to the untrained observer so it is possible to install the new spring kit in the heads that KTM is currently shipping from parts stock, and onto older cylinder heads. The spring seat washer will soon fail causing the same valve train problem as the earlier two-spring design. I had to make a modification to the new head that I recently purchased from KTM that involved boring the spring seat recess in the head to a larger diameter. Not a problem for me, a performance machinist with a vertical mill and several boring tools, but a big problem for the average guy who expects that the parts will fit correctly. What’s worse is that there was no written communication in either parts box warning that the head would need to be modified to fit the new spring.
If you own a KTM 400 or 520 I suggest that you have your local dealer modify the head for the new conical valve springs and install the new parts with fresh stem seals. If you’ve been riding the bike for a few seasons it’s about time that the head was checked for routine maintenance like the condition of the valves, guides, seats and stem seals. If your engine fails there is no warranty or recall that I know of.
One final note, in September of 2002 I attended a national product liability conference at the University of Wisconsin/Madison and there were representatives from some American motorcycle manufacturers. One of the points covered concerned recalls and warnings. The theme expressed by the speakers was that honesty is the best policy. In my opinion profiting from a design flaw is inexcusable. In the near future I hope to see the management of KTM in America straighten out this debacle by sending technical communications to dealers and owners warning of this potential problem, labeling cylinder heads that require machining to accept the larger diameter spring seat washers or pull them from stock, and providing detailed instructions on exactly how to repair bikes that are currently in use.
Eric Gorr, a happy owner of a KTM 640 Adventure