TiTan Cranks

Market leading crankshafts for the Yamaha TZ 350 & TZ 750

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About

Forging:

  • TiTan Cranks are made from a derivative of EN36 'forgings' and heat treated to give a hardened surface whilst maintaining a high core strength.
  • Forging gives much better grain orientation, thus improving tensile and fatigue strength.
  • Forging reduces the amount of machining, which can help reduce distortion in subsequent stress relieving & hardening processes.

Assembly

The TiTan Crankshaft comes complete with bearings to the original Yamaha specifications (or equivalent) depending on availability.

The crankshafts' flywheels are all 'factory matched sets' for each crank, to maintain a high degree of trueness. Parts should never be mixed without reference to our technical information. This is especially so for the centre M/F flywheels which need a very precise interference fit.

The special 'TiTan' centre labyrinth seal has two 'O' ring seals added on the O.D. to seal across the crankcase at this point, which in turn allows a better 'pinch' of the centre main bearings. For this reason, the lab seal is actually slightly smaller on O.D. than the centre bearings. Fitting/tightening the drive gear on end of crankshaft must be done seperately prior to fitting the crankshaft into the crank cases. Do not 'wedge' the primary gear to tighten it whilst the crank is in the crank cases. This can put the crank out of true!

Ignition taper

The taper on the ignition side flywheel is as per standard Yamaha 'G' model with the 12.0mm x 1.25mm threaded end for ignition rotor retaining nut. However, for those using a Krober ignition and 'windmill' rotor, the shorter TZ A/B/C type ignition flywheel with 7.0mm x 1.0mm female thread is available.

Service Information

Centre shaft key and keyway, on earlier cranks

This key is purely for aligning the centre flywheels at 180deg when assembling the inner flywheels. It takes no driving loads which is achieved by the interference fit.

The mail centre shaft key and keyway are a machined fit, so care must be taken to avoid the key being too far proud of the diameter of the shaft in which it is fitted. The total height across the key and shaft should be 21.9mm (see Fig. 1)

Special note for crankshafts from number 057 and later

Cranks assembled after number 057 were assembled on a special 180 degree jig, and therefore did not need the woodruff key to align them. However, when these cranks require rebuilding, we can do that for you as part of our rebuild service.

If you rebuild your own cranks with a key, they can be fitted to the dimensions shown in Fig. 1

Figure 1

Contact

Email: info@titancranks.com

Telephone: +44 (0)114 233 7460

49 Harrison Road, Sheffield, S6 4NA.