Fuel Petcock 'Off' Mod

[evan_calgary]

Hi All,

Can someone explain in laymans terms how I convert the OEM fuel petcock from the standard setup to one with a true off position?  I hate having to rely on float needle seals and have already had one crankcase full of petrol.

So far I see:
remove the vacuum line and plug both ends.
unscrew bolts on face, rotate chrome plate and actual turning mechanism 180 degrees then rescrew.

Can someone help me with the following?

Additional notes included o-ring on vacuum membrane
Bent spring to increase force.

Thanks!

[JKV45]

I went with a RGV petcock that has an "OFF" position.

[biggz]

I did the same as JVK45 (RGV part, carb vacuum spigot capped) and then found that it still seeped some fuel when Off. Added an inline shutoff which did the trick. Having said that, the RGV tap seems to have managed to seal itself properly after some use. One downside: the RGV one is stiff, with a short lever, so difficult to shift to Reserve on the move.

Laurie

Edit: be wary of aftermarket as the flow rate may be lower - I measured 75sec to flow 1 litre from an OEM Suzuki tap.

[xstian]

Does the RGV petcock fit straight onto the bottom of the tank?

If so, is there room between the tank and frame?

[totty79]

They are a direct fit, but the one I tried also seeped enough fuel to flood the crank case when left a few weeks. Internally they work buy rotating a plastic cone, unlike most others that have a rubber membrane.

[m in sc]

on my 1kt, i actually got a 90 degree motion pro manual valve, 1/8 npt on one end and barb on the other, and replaced the pressed in 90 degree fitting at the outlet. went back to a stock petcock but use that for actual cut off for when it sits. was a super easy mod. 

[James P]

It is important to note here that the RGV fuel tap conversion will unlikely work very well on 1KT-based TZR models because (even if the RGV tap fits, as Xstian asks) you probably won't be able to reach the lever to turn it on or off. It does work on R1-Zs (and some other TZRs) because the standard fuel tap is in a different (more conventional) form.

In 2013, I posted some details of the ZXR750 fuel tap conversion I did - see here: https://pure2strokespirit.net/forums/index.php?topic=887.msg9804#msg9804.

Regards,
James