Installing MikesXS Non-Vacuum Petcocks on Later Models

[YamadudeXS650C]

Today I am installing MikesXS Non-vacuum petcocks on my single-petcock '83 and '80 Specials.

Forgive me if this is all repetitive, but I thought that at least some aspects of the install might be helpful to somebody.

So, here is the unit on my '80, which works fine, but I'd rather go Non-vacuum for the obvious reasons.

As you can see, the ideal is to aim the gas with a 90 degree fitting towards the center of the bike. The new petcock comes with straight and 90 degree fittings.
However, when I tightened one of the 90 fittings all the way in, it was angled at about 2:00, not at all ideal:

This angle is best, but some sort of modification would need to be done:

The other Mikes' petcock tightened to an angle that was worse, 7:00. (not pictured)

However, adding extra filtration is a good thing, and a 90 degree filter attached to the straight petcock fitting (provided) will fit into the chassis fairly well:

For accessible connections, I use stainless safety wire, which gives me peace of mind.

No need to drain the gas if you have 1/3 of a tank or less, just prop it up with a gallon oil bottle:

Clean the tank connection surface,

and use new sealing washers and screws. Dirt cheap at Mikes:

The sealing washers go onto the screws VERY tight. I grab them with my fingers:

No need to use any sealing goop, in my experience.

Installed:

The filter tucks in fairly well. As you can see, I wrap the safety wire 3 times, and twist. Not too tight, tho.

Hope this is useful to someone.

 

[YamadudeXS650C]

BTW, a shot of silicone spray on the tank grommets eases the tank in quite nicely:

And, obviously, you'll have to plug the nipple on the intake manifold. You can buy new rubber ones, but I use a section of cloth-braided 7.0 x 2.5mm gas line plugged with a brass, shouldered 22 caliber shell casing. Works quite well.

 

[robinc]

Nice job Dude! And great write up and pics.

I like the stainless safety wire idea, but I'm not familiar with it. I have used the stainless clip hose clamps but you could probably buy a whole spool of that stuff for the cost of a couple little bags of clamps.

What can you tell me about it?

Thanks.

 

[YamadudeXS650C]

Update:

As I head into installing the new petcock to the '83, I see that the side cover intrudes into the chassis quite a lot, and much deeper than the '80:

Therefore, it will be more difficult to get the fairly large 90 degree filter into there. Considering that the Mikes' petcock already has an internal filter, I worked on getting the 90 deg. fitting to tighten at a good angle. I discovered that the red sealing washer under the plug on the right,

is a few thousands of an inch thinner than the one on the 90 deg. fitting, and when switched, I was able to get the 4:00 angle which is ideal.

Details re: this Mikes' petcock pt. # 20-0019:

This petcock is of the earlier model design with a wider mounting flange of 46mm center to center to be comparable with the vacuum type base. The MikesXS petcocks will fit to either left or right due to dual inlet ports and interchangeable fittings. Includes: Fuel Tank O-Ring Seal, (2) 90 degree, (1) straight, (1) port plug and an extra nylon filter.

I don't work for MikesXS, BTW, but I do buy some of their parts.

 

[YamadudeXS650C]

Nice job Dude! And great write up and pics.

I like the stainless safety wire idea, but I'm not familiar with it. I have used the stainless clip hose clamps but you could probably buy a whole spool of that stuff for the cost of a couple little bags of clamps.

What can you tell me about it?

Thanks.

Thanks for the feedback, Robin,

Safety wire: left over from my racing years. When I was racing the kart in the WKA, the technical regulations were such that all primary attachment nuts had to be castle nuts, and all those bolts drilled, like our XS axle nuts. Cotter keys disallowed. SS Safety wire, only. This was important because of the high speeds, e.g. 125 mph on the high banks of Daytona International Speedway (part of the road course), 100 mph down the front stretch at Road Atlanta, and 95 mph down the backstretch at Mid Ohio. I was following a guy down the latter stretch back in the late 90's, and his axle shifted due to a failure in safety tying. He hit the wall, and died instantly.

Here is a blurry pic of the castle attachment nut for the butterfly steering wheel, altho it has a cotter key. I was "club racing" at the time, and the regs were less stringent.

 

[Mailman]

Very nice work, that is a job I certainly would have done myself if I had vacuum operated petcocks. I just never liked the bulky, needlessly complicated nature of them. Like Robin, I also liked the the use of safety wire as opposed to the bulkier hose clamps.
Good write up. Good photos.

 

[YamadudeXS650C]

Nice job Dude! And great write up and pics.

I like the stainless safety wire idea, but I'm not familiar with it. I have used the stainless clip hose clamps but you could probably buy a whole spool of that stuff for the cost of a couple little bags of clamps.

What can you tell me about it?

Thanks.

One can get safety wire at racing parts shops or karting outlets such as American Power Sports.
Correction: APS just does fun karts, now. Try TS Racing http://www.tsracing.com/

 

[robinc]

Ah, cool Dude. I will be switching my vacuum petcocks on my 78, if I ever get back to it because they are leaking.
We have a couple specialty shops here in town that build stock cars. When I'm by one of them I'll check it out.

Thanks.

 

[weekendrider]

If you are replacing the base screws, allen/hex heads screws are available. Much easier to get a hex key to them than a screwdriver.
The petcocks I got from Mikes do have a brass screen in them but it is just a piece rolled up and open ended. You might consider soldering the side and crimping the end.

 

[YamadudeXS650C]

If you are replacing the base screws, allen/hex heads screws are available. Much easier to get a hex key to them than a screwdriver.
The petcocks I got from Mikes do have a brass screen in them but it is just a piece rolled up and open ended. You might consider soldering the side and crimping the end.

I do have allen "button" head screws with the proper thread, but the head is much smaller than the ones from Mikes, the latter which create a sealing surface area that is almost the same as the OEM screws.

And if one has a screwdriver with the proper, LARGE Phillips driver, you can torque those babies down as hard as you want, and make those sealing washers scream bloody murder, but such torque isn't actually necessary

The internal brass screen is actually a redundant filter, with the nylon screens on both of the intake tubes (I only pictured one screen installed). So, on the '80, I actually added a third screen/filter with the 90 deg. item.

 

[retiredgentleman]

Those little white nylon screens will not stay on the intake tube. You will find them laying in the bottom of the tank.

 

[YamadudeXS650C]

Those little white nylon screens will not stay on the intake tube. You will find them laying in the bottom of the tank.

Well, now THAT certainly blows a big hole in the side of the airplane !

RG, please share your empirical data on that statement.........

 

[pckopp]

please share your empirical data on that statement.........

I'm not RG, but I installed those same petcocks (purchased via eBay at a substantial discount from MikesXS) and installed on a 79 Special. I carefully pushed the nylon screens tightly onto the tubes, but when I pulled them off 3 of the 4 were on the bottom of the tank. They were hard to pull of by hand but in the tank they seem to float right off.

BTW, the screws and gaskets for those from MikesXS comes with flat washers also. Didn't look like you used them.

 

[YamadudeXS650C]

I'm not RG, but I installed those same petcocks (purchased via eBay at a substantial discount from MikesXS) and installed on a 79 Special. I carefully pushed the nylon screens tightly onto the tubes, but when I pulled them off 3 of the 4 were on the bottom of the tank. They were hard to pull of by hand but in the tank they seem to float right off.

BTW, the screws and gaskets for those from MikesXS comes with flat washers also. Didn't look like you used them.

Well, it SEEMS that we've got some actual empirical data on the nylon screens "floating off", although you did not purchase the products from Mikes, and therefore it raises some question as to what the exact product was that you were using.

And how long ago did you purchase these products? Product development is ongoing, sometimes.

As for the metal washers that come with the 20-0020 kit, they are not called for in the OEM application, and in my opinion, will increase the probability of a leak. I tossed them into my bin of 10, 000 washers. No leaks in my job. Issue settled. Altho I appreciate the concern.

 

[YamadudeXS650C]

A twist of SS safety wire would seem to be prudent on the nylon screens, even given the very limited data presented so far as to some doubt about them staying put. Alternatively, perhaps a touch of Seal-All, although the Eclectic Products tech department was hesitant to actually state to me 3 months ago that it is gas proof,as their ads claim. Therefore, I engaged the Eclectic Products company in a collaborative research effort. I am testing the product (3 months running, at this point) Seal All on a brass float in my Kawasaki F11, as well as on a brass tube I have immersed long-term in gasoline:

 

[pckopp]

Well, it SEEMS that we've got some actual empirical data on the nylon screens "floating off", although you did not purchase the products from Mikes, and therefore it raises some question as to what the exact product was that you were using.

And how long ago did you purchase these products?

The petcocks are identical. They arrived on my doorstep Friday, July 28.
http://www.ebay.com/itm/Yamaha-Petc...47-24500-02-/192212777293?hash=item2cc0c6394d

 

[weekendrider]

Even if they don't fall off they will warp and split at the ribs. They just don't do well with ethanol fuel.
Or that was my experience.
You would do better to fashion a brass screen cap for the tubes imo.

 

[gggGary]

I like the OEM packing washers, some sort of lead amalgam? I have reused them many times with no issues. I also stick with the #3 phillips. I use fat o-rings from the "red metric o-ring box" to make the petcock/tank seal. They need to be pushed into the groove as the screws are tightened. I also remove any paint and sand the tank so no sharp ridges interfere with the seal. I then seal any paint "edges" with a bit of epoxy or crazy glue so gas can't seep into the primer and bubble the top coats, do this at the gas cap also!
I found a (common?) issue with the vacuum petcocks is a tiny one way rubber seal in the vacuum barb. After years of setting It works so well that the petcock never shuts off even after the bike is sitting for several days. I think as designed, it slowly bled off vacuum, fuel shut off occurs a few seconds after motor shut off. I lightly scratched that seat and it is working fine now. I wonder if that was the issue that XJWMX had with his vacuum petcock a few years ago. An old rubber seal that works TOO good, who'd a thunk it? Also on the OEM petcock the fuel barb is epoxied in, that has often failed and needs to be re-epoxied. JB weld seems to do the job, a couple I've done have been in use for years now.

 

[weekendrider]

If you are looking for alternatives to the washer Ace hardware has a gray colored fiber washer that has worked for me. It is SAE and has to be resized but with a spoonful of tenacity it is doable.
gggGary how do you get those old washers off?
Mine always seem permanently glued to the screw head.
Has no one else had to cut phillps screws off because of boogered threads? I spent two hours just last night drilling screw shanks out to rescue a tank.

 

[gggGary]

Sometimes a razor blade to remove old washers. Have yet to meet a screw I couldn't get off. Might have slotted one with a dremel cut off a time or two. A long shank #3 in the impact wrench is helpful.... Just don't bang it hard enough to dent the tank.