TOPIC:

JMKZHI, the spacing on mine is 34mm. Seems like there are a few models with the same spacing, so that's handy if I decide to replace.

Unfortunately the fuel outlet on the Raptor valve is to the rear of the bike, and there really isn't enough room on mine for that location, so I'll modify mine. You're right that I can just plug the vacuum line and use "pri" as "on" and the other two as "off." In that configuration it draws from the reserve port, so I get all of my fuel, but if I run dry, I'm done. With one small modification I can have both a main and a reserve though.

I've attached a picture to show what I'm planning. The picture is from a Yamaha triple, but the differences aren't important to describing what I'm going to do. Labels in the pic aren't mine. In the picture the lever has a "J" shaped channel. It used to be 2 channels, 1 semi-circle and 1 straight line. The dam between them has been removed. Mine looks the same, but the "J" faces the other way. Or at least it will when I remove the dam between my two. Once that's done "pri" will be "res," "on" will be "on," and "res" will be "off."

I've already got a selector seal coming, and tomorrow I'll go get a couple of Buna-n o-rings to replace the 2 in the valve. A little grinding and surface polishing, and I should be good to go.

Are you able to shut off the flow of fuel with the lever modification?

daveo wrote: Are you able to shut off the flow of fuel with the lever modification?

Yup! With the modification, and with no vacuum attached, when you put it on what is currently "res" the fuel can flow from the reserve port to the main inlet port, but not the outlet port. I'll take some pics tomorrow of the CSR's petcock. With those I can add diagrams of the flow path before and after to show what I'm up to.

Please conduct sufficient performance tests with some non-flammable liquid other than gasoline to prove completely that your theory will work.
IMO, this is a risky idea with potential for harmful results.

Adding diagrams to the pictures I took was becoming so involved and was obscuring the petcock to the point it being in the image became irrelevant. So I just made a graphic that shows how it functions, both before and after, in each position.

I will agree that any time you modify a fuel system there is risk and you need to consider all of the implications of what you are doing. You need to be careful just working on a fuel system. Gasoline is far more dangerous than most people give it credit for. That said, a gravity-fed system is less dangerous than a pressurized system. I am not making a modification with the potential for introducing a leak. When the vacuum is disconnected this petcock works exactly like a manual petcock, with one exception. That exception is the channels in the lever. All I am doing is connecting the two channels so that they become a single channel identical to the channel in a manual petcock.

Hopefully the attached graphic makes what I am doing clear. It is clear to me, but then I created it, it would be.

Add to your drawings the rubber gasket raised seal ridge that exists around each petcock orifice. Note how that continuous ridge follows around and past the point of alignment of each circle, and note especially that seal loss will result should the smooth-flat inside face of the lever fail to maintain continual contact with it.
The above statement may not be an accurate assessment, and is not intended to provide any level of consent or assurance that your design modification may be safe or correct.


PS I wish you every success with your project, with precaution and safety in-mind.

It appears it won't leak externally due to the O ring on the lever but may leak internally due to the low spots. I'd like to see how this thing turns out.
Steve

So,Hannah, what news? Has the modification worked out as you intended?

What a delayed response! I'll just claim it was because I wanted to perform a thorough road test before giving an opinion. Yeah that's it, that's the ticket! It wasn't because I spaced looking back into this post.
So I did run it just without vacuum for a couple of months, which was fine, but I only had to bitten by the lack of a reserve once to get me moving on the modification.
The factory channels were only chamfered rather than smoothly rounded at the seal surface, so I fixed that while I was in there. I also polished the seal surface. Not quite to a mirror finish, but much smoother than the factory. SOOO much silkier to operate now. After about 2 years and 6k miles it's still working flawlessly.

Yes, you'll notice in the picture that I didn't make my notch quite as deep as the factory channels. It's about 1mm proud. It has yet to present a problem, and it has yet to show any damage to the seal.