Fuel tap conversion

[James P]

For those interested in converting from the standard vacuum-operated fuel tap to a normal on-off-reserve type, I have come across the ZXR750 tap:





The internal passages are not as large as the standard TZR tap, but if they are large enough to flow sufficient fuel for a 750, they should be fine! The second photo shows the tap mounted to the standard TZR tap bracket using an adaptor made from aluminium plate.
This is a Taiyo Giken tap, the same brand as fitted to the TZR and many other Japanese bikes. The rubber gasket and O-ring are generic ones which should be fairly easy to obtain.
The only problem I foresee so far is the larger size of the standard TZR fuel tank outlet - I'm hoping that 8mm fuel hose will fit (I've only got 6mm hose in stock at the moment). If not, I'll have to get or make two reducers.
Input welcome from anyone who is doing (or has done) a similar conversion using any other tap(s)!

Regards,
James

Edit: 8mm fuel hose fits the standard TZR fuel tank outlet with a bit of persuasion, so no problems there. I have added a quick-release connector in the hose between the tap and the T-piece, so tank removal is a bit easier.

[srxburns]

How did this end up working for you? what is the point of the standard vac set up with the TZR250, why do you need a vac as the gravity should do the job to get fuel to the carb shouldn't it?? What did you do with the vac pipe coming off the carb, did you just plug it?

Thanks
James

[Paul]

How did this end up working for you? what is the point of the standard vac set up with the TZR250, why do you need a vac as the gravity should do the job to get fuel to the carb shouldn't it?? What did you do with the vac pipe coming off the carb, did you just plug it?

Thanks
James

james, the vacuum acts like an on/off switch only, doesn't suck the petrol.

[James P]

How did this end up working for you? what is the point of the standard vac set up with the TZR250, why do you need a vac as the gravity should do the job to get fuel to the carb shouldn't it?? What did you do with the vac pipe coming off the carb, did you just plug it?

Thanks
James

The ZXR750 fuel tap works fine! With the quick-release fuel coupling, tank removal is probably about as easy as it could ever be.
I gather the point of the vacuum-operated tap was/is to make it unnecessary to turn off the fuel tap when parking the bike. However, as far as I am concerned, the additional apparatus (vacuum line, diaphragm etc.) is just more stuff to go wrong  .
I pulled out the brass vacuum fitting from the left-hand carb, tapped the hole and inserted a Loctited grub screw. However, you could just fold over the rubber vacuum line and crimp it.

Regards,
James