Crying Petcock

[robindean]

I've mentioned this before as a subtopic within some of my previous posts.

Basically, the petcock on my bike is old and cries. I have an in-line valve that I use to shut it off when parked.

I have two questions.

The first is, is it okay to ride with the petcock set to the "pre" position? This seems to let the gas flow directly as though it were a generic petcock.

My second question is are there any replacement petcocks out there that will convert me from vacuum to non-vacuum? Links are appreciated. I'm googling as we speak.

 

[WT100]

I'm hoping this one from Amazon will work. I don't want to rebuild another one either.

http://www.amazon.com/gp/product/B001KO0Q8Q/ref=ox_sc_act_title_1?ie=UTF8&m=A3TGC5XRRCX4P2

 

[xschris]

I am not sure about the dohc models but mikesxs sells a non-vacuum one that fits the sohc xs400's tanks.

 

[WT100]

With shipping your looking at $56. That's just crazy for such a simple thing.

 

[xschris]

I will cost a lot more if your bike blows up from a leaky petcock

 

[WT100]

lol

If you have Amazon prime - shipping is free on this one. So almost $20 less.

http://www.bhphotovideo.com/c/product/476533-REG/Joby_Gorillapod_SLR_Zoom_Flexible_Mini_Tripod.html

No i don't work for them...

 

[xschris]

Then I would go for it. If it works good let us know

 

[WT100]

Went for this one. I like simple. $27 to my door.

I've survived wars AND N Korea. It THIS blows me up, the irony will at least make me smile in heaven.

http://www.amazon.com/gp/product/B001KO0QCC/ref=ox_sc_act_title_1?ie=UTF8&m=A3TGC5XRRCX4P2

I'll update when i get it.

 

[domains]

I took mine off otherday and on reserve it bypassed diafram... seems it was invented to stop overflowing carbs from filling base with gas messing up main bearings.

i messed up a gsxr1100 motor once that leaked gas in base... was running like new just before

You can always leave it on reserve if you got a new float valve and seat.

 

[robindean]

WT100 ... crackin' me up man LOL!

I suppose I should measure the screw placement center-to-center and then compare.
My bike being a SECA somehow has me a little bit isolated even here.

I too am concerned about over-filling the bowls with a non-vac petcock. Anyone else have experience with this?

 

[robindean]

Another member messaged me saying to make use of these:

http://www.partsnmore.com/parts/yamaha/xs400f/?filters[category]=carb

Assuming they work with my ride, not too shabby.

I still am concerned about a) the bowls and b) how to safely/properly seal off the vacuum.

 

[WT100]

Adapter plate is a good idea but with shipping and then the new "Universal" petcock you still get up there. For those who have a universal one in their parts stash it is a great option.

 

[WT100]

As far as the conversion to non-vacuum. MikesXS indicates, it is not an issue. They actually recommend it.

 

[Charles]

I too am concerned about over-filling the bowls with a non-vac petcock. Anyone else have experience with this?

As long as your float valve is working properly, you won't overfill the bowls.

 

[robindean]

That's excellent.

I'll look again but I don't remember seeing an overflow drain on the bowls. I think it's fully enclosed (sealed). That would basically just flood the engine, right? However, with working float valves all is well?

 

[xschris]

With the non-vacuum ones you will need to turn them on when you start the bike and turn them off when you are done riding. Otherwise you could flood the engine if the carb float needles are bad.

 

[WT100]

With the non-vacuum ones you will need to turn them on when you start the bike and turn them off when you are done riding. Otherwise you could flood the engine if the carb float needles are bad.

Some of us are so old that is how we thought they ALL worked...

 

[robindean]

With the non-vacuum ones you will need to turn them on when you start the bike and turn them off when you are done riding. Otherwise you could flood the engine if the carb float needles are bad.

Right. I get that. Now, what about sealing off the vacuum and running the engine on "pre" while I wait for my new petcock to arrive?

I read somewhere that running on "pre" for too long is a bad idea. Thoughts?

 

[xschris]

Do you mean pri? or prime. I would just turn the petcock to on when you are done. Gas should not flow when there is no vacuum in this position. If you do have gas flow with no vacuum that you will need to crimp the hose or something to stop the gas. You don't want any gas to flow with the engine off

 

[robindean]

I understand the gas flow issue. Yes, I meant "Pre" ... safe for use while riding?