Petcock Screw Size For The Xs750: What You Need To Know

The Yamaha XS750 is a much-loved motorcycle, but like any vehicle, it has its quirks and foibles. One of the most common issues owners face is problems with the petcock, the tap that controls the flow of fuel from the tank to the engine. The petcock is a simple device, but it can be a headache to fix when things go wrong. One of the most common problems is leaking, which can be caused by anything from old gaskets to incorrectly installed washers. Another issue is the Philips head screws that hold the petcock together, which can be easily stripped and are widely disliked by XS750 owners. When replacing the petcock, it's important to get the right size, with 42mm and 46mm options available depending on the model year.

XS750 petcock screw size compatibility with Yamaha XS650

The XS750 and XS650 Yamaha motorcycles have the same petcock bolt spacing of approximately 1.78" or 45-46 mm. The bolt hole centre-to-centre distance is 46mm for the XS750 and 1978-1979 models of the XS650, which use two petcocks. The 1980-1984 models of the XS650 use one petcock.

The Carbman Petcock Fuel Gas Tap Valve is compatible with both the Yamaha XS650 and XS750, as well as other Yamaha models. It has 3 positions: Off, On, and Reserve. The bolt hole centre-to-centre distance is 46mm. It has 2 outlet ports that fit either the right or left side.

The direction of the fuel line is different between the XS750 and XS650. The XS650 has shorter fuel screens than the XS750.

XS750 petcock screw size compatibility with Yamaha XS1100

The petcock screw size for the Yamaha XS750 is 46mm. This measurement is specifically for the vacuum petcocks on the 1979 standard model. The 1977 standard model has a smaller petcock screw size of 42mm.

The XS750's petcock screw size is not compatible with the Yamaha XS1100. The XS1100 has a larger petcock screw size of 54mm. This is a significant difference in size, requiring different tools and parts for maintenance or modifications.

It is important to note that the petcock screw size may vary depending on the year and model of the XS750. While the 1979 standard model has a 46mm petcock screw size, other models, such as the 1977 standard, have a smaller 42mm size.

When working on a Yamaha XS motorcycle, it is crucial to identify the specific model and year to ensure compatibility with parts and maintenance procedures. This information can usually be found on the vehicle identification number (VIN) plate, which is typically located on the steering neck.

In addition to the petcock screw size, the fuel line direction may also differ between the XS750 and XS1100, further emphasizing the importance of model-specific information when working on these motorcycles.

XS750 petcock screw size compatibility with Yamaha XS850

The petcock screw size for the Yamaha XS750 is 46mm, which is compatible with the Yamaha XS850. The XS750 uses a manual petcock with 42mm mounting holes and left and right-hand threads. The petcock screw size is important for ensuring a proper fuel flow and preventing leaks.

The Yamaha XS750 and XS850 are both part of the XS series of motorcycles, which were produced from 1976 to 1985. The XS750 was introduced in 1976 as an upgrade to the XS650, offering a larger engine and improved performance. The XS850, released in 1980, featured an even bigger engine and more powerful performance.

While the XS750 and XS850 share many similarities, there are some differences to note. The XS850 has a larger displacement and a different engine design, utilising a triple-disc cylinder configuration compared to the XS750's inline-three setup. This change in engine design may require some modifications when using XS750 petcocks on the XS850, particularly with fuel line orientation and petcock spacing.

The petcock is a vital component in the fuel system, controlling the flow of fuel from the tank to the engine. It is essential to ensure that the petcock is functioning correctly to maintain the motorcycle's performance and prevent fuel leaks.

When replacing or upgrading petcocks, it is crucial to consider the screw size and spacing to ensure compatibility. The 46mm screw size of the XS750 petcock falls within the acceptable range for the XS850, making them compatible. However, it is always recommended to refer to the manufacturer's specifications and seek expert advice when making modifications to ensure safety and optimal performance.

XS750 petcock screw size compatibility with Yamaha SR500

The Yamaha Petcock is compatible with several Yamaha models, including the SR500 and XS750. This petcock is a fuel valve that serves as a replacement for the stock vacuum petcock in later models. The mounting holes are 46mm apart, measured from centre to centre.

The petcock is gravity-fed and has a redesigned wider flange to fit the gas tank of later Yamaha models. It comes with two 90-degree fittings, one straight fitting, one port plug, and an o-ring that seals against the tank. It also features a ribbed fuel outlet for use with a 1/4" fuel line or a Genuine Honda 5.5mm line.

This product fits both the left and right sides of the Yamaha SR500 and XS750 models. It is important to check the gas tank mounting holes before ordering to ensure a proper fit.

The Yamaha Petcock is a suitable replacement for the stock vacuum petcock in the Yamaha SR500 and XS750 models. The compatibility of the screw size between the two models indicates that this petcock can be used as an interchangeable part.

XS750 petcock screw size for rebuild kits

If you're rebuilding your petcock, you've probably already discovered that the screws are a pain to deal with. The Philips screws that come standard on many bikes are widely disliked, with some people going so far as to say that their inventor was "intent on causing great frustration for millions of people".

If you're looking to replace your petcock screws, it's important to get the right size. The screws that attach the petcock to the tank are different from the screws on the petcock's back plate. The back plate screws are tapered, making them particularly challenging to replace. The screws attaching the petcock to the tank are often Philips head screws, which can be easily stripped.

One option for replacement is to use hex bolts. These can be found at most hardware stores, and they may be less likely to strip than Philips head screws. Another option is to replace the screws with socket-head capscrews (SHCS) or Allen bolts. These are usually made of harder steel and are less likely to strip.

When replacing the screws, it's important to consider the size of the fuel line. The fuel line on an XS750 tank points in a different direction than on an XS650, so the screws need to be sized accordingly. The petcock bolt spacing on an XS650 is approximately 1.78" or 45-46 mm, while the spacing on an XS750 is 46 mm.

In addition to the size and type of screw, it's important to consider the condition of the gaskets and washers. Old or damaged gaskets can cause fuel leaks, so it may be necessary to replace them with new, thicker gaskets. Washers made of fibre or Hylomar Blue gasket goo can also help to prevent leaks.

When working on your petcock, it's important to be careful not to damage the fuel tank. An impact driver can be useful for removing stubborn screws, but it's important not to use too much force and squish the tank.

By following these tips and choosing the right size and type of screw, you can successfully rebuild your XS750 petcock and get your bike running smoothly again.

Frequently asked questions