250 mil I believe...
190cc on sx50 jr 210cc on 50sx sr (02-09) on both
No compression means time for a rebuild.
A KTM 65 SX should typically have a compression ratio of around 12:1 to 14:1. In terms of actual compression pressure, it can range from 120 to 150 psi when tested with a compression gauge. Maintaining proper compression is crucial for optimal performance, so ensure that the engine is in good condition and that the piston and rings are not worn. Regular maintenance and checks are recommended to keep the compression within this range.
12.0:1
11.0:1
125-130 lbs
A KTM 85 typically should have a compression ratio in the range of 160 to 180 psi (pounds per square inch) when measured with a compression tester. This level indicates a healthy engine and optimal performance. If the compression is significantly lower, it may suggest wear or damage in the engine components, requiring inspection or maintenance. Regular checks are essential to ensure the bike operates efficiently.
The compression ratio of a KTM 450, specifically the KTM 450 SX-F, is typically around 13.5:1. This high compression ratio contributes to the bike's powerful performance and responsiveness. However, variations may exist based on specific model years and configurations. Always refer to the manufacturer's specifications for the most accurate information.
Not an easy question to answer. Compression readings are greatly impacted by your gauge, altitude, air density etc. I have seen many places where the compression on a KTM 65 should be at least 135PSI. I live at 7,000 feet, I purchased a cheap Harbor Freight compression gauge. I tested compression on 2 new KTM 65s and 2 Cobra 50s. The KTMs read between 88 and 95 PSI, the Cobras read between 60 and 65 psi. All the bikes run great and have plenty of power. I know my gauge reads low, I also had to use an adapter to fit the gauge on the cylinder head. From what I understand the adaptor also adversely impacts readings. I think the best bet calls for measuring compression when the engine is new, record the PSI, date temperature, elevation and gauge used as a benchmark. Check the compression again at intervals, when compression drops by more than 10% from the benchmark consider a rebuild. When compression drops by more than 20% rebuild is imminent.
2 Wheel Tuesday - 2003 Mike Lafferty Factory KTM 1-1 was released on: USA: August 2003
lots: kowasaki: kx65, kx85 kx100, kx250. yamaha: pw50, yz85, yz125, yz250. ktm: 50sx, 65sx, 85sx, 105sx, 125sx, 150sx, 250sx, 320sx. suzuki: jr50, jr80, rm65, rm85, rm125, rm250 honda: cr85, cr125, cr250 and much more