150 amp solenoid/relay - where can I get one?

[rustyrobot]

My bike has a cruddy 50 amp solenoid that is a known weakness, and I want to replace it with something a little beefier and more reliable. Most people use a Yamaha part (4KD-81940-00-00) (http://www.ebay.com/itm/Solenoid-Relay-Yamaha-4KB-81940-00-00-4KD-81940-00-00-/280595689097) but I have heard of some folks using a 150 amp solenoid.

First thing - will putting in a solenoid with higher amperage have any negative side effects?
Second thing - where can I buy one of these in New Zealand? I'm an impatient bastard and google hasn't turned up anything yet... any clues where to start?

Cheers

This is the original part:
294226

[Akzle]

thats a fuckload of amps. Id be asking about security door strikers that can be adapted to porpoise.

[paturoa]

The uprated solenoid would only be a problem if the input resistance was too low for the starter cct. The resistance or current rating of the actuation cct is normaly in the specs.

Any decent auto-lecky would be a good place to start, they will have several catalogues and cross references.