corona36
Amateur Restorer
Got it. Now do I want to measure from the center of the holes or from the edges? I would assume center, but I wouldn't want to make anything out of u and me.
-
Enjoy XS400.com? Consider making a donation to help support the site.
XS400.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
petcock replacement
- Thread starter badgertom
- Start date
CadXS
XS400 Addict
Centre to centre.
corona36
Amateur Restorer
An update:
Measured out the distance and found it to be 44mm. Ordered the parts from partsnmore. Will have pics when I get them in.
Measured out the distance and found it to be 44mm. Ordered the parts from partsnmore. Will have pics when I get them in.
Ok, so MikesXS is out of stock. If I do order from partsnmore which parts do I need?
Definately the Universal Fuel Petcock, but which Petcock Adaptor Plate would I need seeing as they list 3 on there? Would I also need the Fuel Petcock Adaptor Nut since there are 2 listed there?
It would be so much easier if there were some in stock at MikesXS, but since I want to get this thing running ASAP I'm going to need to go with partsnmore. I just dont know which parts I need.
I am running the universal manual petcock from partsnmore. For my 78 I think it was the largest of the 3 plate adapters. I just measured from the center of one bolt hole to the center of the other bolt hole a dozen times from different sides to be absolutely sure.
The screen filter on this universal petcock did not fit in my tank without making the hole larger with a dremel. Alternatively you can rip the filter off and just run an in-line fuel filter which costs about 2 bucks from a local shop.
I did not need any sort of adapter nuts just the petcock and the mounting plate.
I also made a post about this and I think I posted the size. It may have been the 44 too but I cant remember.
hmusket
XS400 Addict
I don't know if it matters on the universal petcock, but on the standard Yamaha vacuum petcock if the screen filter assembly is not attached the reserve safeguard feature doesn't work, so when you find you need to switch to reserve, you've already run out of gas.
Interesting. How does the screen affect the reserve exactly? The universal one is non-vacuum. I ran out of fuel with it once already with no screen on it. The reserve seemed to take a minute to start flowing ok, but it got me to the gas station.
hmusket
XS400 Addict
First of all your petcock is behaving like it should. You start running out of gas just as the traffic light in front of you turns yellow, there's a car behind you right on your tail, grandma in front of you starts slowing down, you're watching all this, at the same time slowing down yourself, thinking about your escape route, trying to fumble with the petcock lever, moving your left hand quickly back to the clutch lever because the engine is starting to bog, have to downshift, back to the petcock. Light turns red, everybody stops, engine runs out of gas, bike turns off, finally get it into reserve. Hope light stays red long enough for gas to start flowing again. No way. Light changes to green, grandma leaves you in the dust, the car behind starts honking, of course you have kickstart only. Gas gets to the carbs after what seems like 2 years, Push your bike to somewhere where you can start it without getting run over. The next day at work someone says " Hey, was that you at the corner of...."
I found out about the filter tubes from my time with an XS850. They were missing from my petcocks, I didn't even know they were supposed to be there, so when the first time I had to switch over from on to reserve I didn't have any gas. Since I didn't know how to explain the function of the filter tube I found this link: http://seca2.forumup.org/about2450-0-asc-15-seca2.html
and a quote from the link:
I found out about the filter tubes from my time with an XS850. They were missing from my petcocks, I didn't even know they were supposed to be there, so when the first time I had to switch over from on to reserve I didn't have any gas. Since I didn't know how to explain the function of the filter tube I found this link: http://seca2.forumup.org/about2450-0-asc-15-seca2.html
and a quote from the link:
I hope that answers the question.
hmusket
XS400 Addict
From Drewpy:
Are you suggesting perhaps I became sidetracked and went off on a tangent? Maybe. LOL
When responding to bcware's question on the relationship between the filter screen assembly and the reserve function, my mind did wander to a time last year, on a ride home from work, on a cold day, trying to switch to reserve wearing heavy gloves.
what was the question again?
Are you suggesting perhaps I became sidetracked and went off on a tangent? Maybe. LOL
When responding to bcware's question on the relationship between the filter screen assembly and the reserve function, my mind did wander to a time last year, on a ride home from work, on a cold day, trying to switch to reserve wearing heavy gloves.
Under Dog
XS400 Addict
I've successfully replaced a leaky vacuum petcock with the manual replacement from Mike'sXS. The swap was an easy bolt on fix, EXCEPT the lever on the petcock hit the bottom edge of the gas tank. I ended up grinding a portion of the lever away and now it works fine...
jomama
XS400 Enthusiast
Hey guys, I dont know about your petcock but mine had the prime setting. Just go to it the gas flows and when you are done riding, turn it back to off or reserve . I think one of the functions of prime is to drain the tank which of course you cant do without vacuum.
Been there, done that. I ground a slot in the lever so in reserve the rim on the bottom of the tank fits in the slot.
lhaolpa
XS400 Junkie
I got a tank from a xs550,as mine was rusted through and had been lined,which came off.The petcock from the 400 and 550 were not the same,different hole spacing,and I'll have to get another.Mine is a '82 xs400rj seca.The tank,I believe will look good as a bobber,as it's wide and blocky....lha
hmusket
XS400 Addict
jlearning1
XS400 Enthusiast
- Messages
- 85
- Reaction score
- 0
- Points
- 6
A quick question on petcocks. I have a 1980 XS400SG and I rebuilt my petcock, and from reading this post, my petcock is in bad shape. When I turn my petcock to RES, PRIME, or RUN, gas continues to run out. It seems I cant stop the gas from running out in no position. Do you think its time for a new Petcock?
Thanks
Thanks
hmusket
XS400 Addict
I thought you fixed it, from what I read in another thread. You could buy another rebuild kit and try it again, but since it didn't work out the first time I would suggest going the manual petcock route.
Also if you think this leaking problem has been going on for a bit, double check your oil for signs of gas leaking into the crankcase.
Also if you think this leaking problem has been going on for a bit, double check your oil for signs of gas leaking into the crankcase.
Last edited:
lhaolpa
XS400 Junkie
You could do like I did;went to Tractor supply[could be Walmart]and got a lawnmower cut-off to put inline,to shut gas flow....lha
jlearning1
XS400 Enthusiast
- Messages
- 85
- Reaction score
- 0
- Points
- 6
I thought I fixed it as well, but after reading a few threads and reading the Service Manual, I noticed that when the fuel petcock is in the Res, or Run position, no fuel should be coming out of the petcock, and mine does. I have disassemblyed the petcock again, just to make sure everything is seated properly. I think I have my turn valve backwards. I think when I took it off initially, the markings on the bezel ring was upside down. I am going to try it that way and see what happens.
Thanks
Thanks
lhaolpa
XS400 Junkie
Must be from a 500,as it's not like that,but wide and blocky.It looks good but doesn't match up with the sidecovers,etc,but they're fibreglass and I can mold extensions to them so I'll not have a gap between the tank and sidecovers and the seat will have to be re-done.....lha
lhaolpa
XS400 Junkie
My '82 xs650 seca turbo tank will not fit the petcock from the tank from my '82 xs400rj secaDOHC.The bolt pattern on the 650 is wider than the 400,and on the websites I've not found the correct one as they don't list the bolt width center to center.I guess that I'll have to e-mail the sites and sort out which I need. lha
