- there are different types of cam chain tensioners...the early cam chains, XS1-TX, had 102 links, an 0.315in/8.0mm pitch, a 34T cam sprocket and were tensioned from the rear by a sprung wheel and guide...later models, TXA on, had 106 links, an 0.3061in/7.774mm pitch, a 36T sprocket and were tensioned from the rear by a sprung guide
early schematic
later schematic
tensioner schematic
- external differences are seen from
...the early XS-XS1B 4 bolt tensioner mount,
...the subsequent thicker XS1B on 6 bolt mounting plate,
...the larger early caps XS1-XS1B, XS1B-TX, TXA-XSB in various shapes and
...the later smaller caps, both without-XSC-XSF-locking nuts and with-XS2F-XSSK
Type A...XS1-XS1B
Type B...XS1B-TX
Type C...TXA-XSB
Type D...XSC-XSF
Type E...XS2F-XSSK
- when tuning your motor start with the cam chain...warm, find TDC and set so the the rod end is flush with the adjuster...worn or loose chains clatter and affect your motors performance in terms of valve timing and particularly with points ignitions which just happen to be cam based...check here
- it is common to find black plastic looking pieces in your sump when changing your oil and cleaning and checking your sump filter...pays to remove the sump plate each time to check the filter, the original ones are known to rupture quite easily, and to look for signs of front cam chain guide wear-the black bits...the guide also wears chain ruts in it
- another tell tale is loud engine noise as the chain wears into the alu guide backing, leaving tell-tale alu filings in your oil and filters
- the front guide wears the most and can be relaced without removing the cylinders by releasing the 2 bolts behind the oil feeder pipe, seen here in front
- you still need to remove the engine, and, carefully so you dont disturb the lower gasket, the head, the chain can be tucked out of the way by releasing the tensioner and easing the bearings off the cam...this way you can slide the cam out without needing to separate the chain...dont forget to tie the chain up so it doesnt drop into the engine...if it does this you can retrieve it by removing the front sump inspection plate and using a coathook lift it while locating it on the crank sprocket
- when installing make sure it is straight before tightening it up
- the rear guide is a little more difficult to replace...easier with the cylinders removed-leave the pistons in the cylinders when removing by releasing the wrist pins, this doesnt disturb the ring to cylinder contact and helps prolong cylinder life
- note when replacing that the locating screws with the shoulder go on the rhs
Parts Chart
early schematic
later schematic
tensioner schematic
- external differences are seen from
...the early XS-XS1B 4 bolt tensioner mount,
...the subsequent thicker XS1B on 6 bolt mounting plate,
...the larger early caps XS1-XS1B, XS1B-TX, TXA-XSB in various shapes and
...the later smaller caps, both without-XSC-XSF-locking nuts and with-XS2F-XSSK
Type A...XS1-XS1B
Type B...XS1B-TX
Type C...TXA-XSB
Type D...XSC-XSF
Type E...XS2F-XSSK
- when tuning your motor start with the cam chain...warm, find TDC and set so the the rod end is flush with the adjuster...worn or loose chains clatter and affect your motors performance in terms of valve timing and particularly with points ignitions which just happen to be cam based...check here
- it is common to find black plastic looking pieces in your sump when changing your oil and cleaning and checking your sump filter...pays to remove the sump plate each time to check the filter, the original ones are known to rupture quite easily, and to look for signs of front cam chain guide wear-the black bits...the guide also wears chain ruts in it
- another tell tale is loud engine noise as the chain wears into the alu guide backing, leaving tell-tale alu filings in your oil and filters
- the front guide wears the most and can be relaced without removing the cylinders by releasing the 2 bolts behind the oil feeder pipe, seen here in front
- you still need to remove the engine, and, carefully so you dont disturb the lower gasket, the head, the chain can be tucked out of the way by releasing the tensioner and easing the bearings off the cam...this way you can slide the cam out without needing to separate the chain...dont forget to tie the chain up so it doesnt drop into the engine...if it does this you can retrieve it by removing the front sump inspection plate and using a coathook lift it while locating it on the crank sprocket
- when installing make sure it is straight before tightening it up
- the rear guide is a little more difficult to replace...easier with the cylinders removed-leave the pistons in the cylinders when removing by releasing the wrist pins, this doesnt disturb the ring to cylinder contact and helps prolong cylinder life
- note when replacing that the locating screws with the shoulder go on the rhs
Parts Chart
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