75 miles and then gotta go to reserve?

Hello Folks,

Rosie is running greatly! And she is getting between 40 and 45 MPG depending on wind and SWMBO twisting the throttle off of stoplights, but...

At about 75 miles, she has to roll over into reserve. These are new petcocks, and no gas is leaking. I know I put in 3.2 gallons to top it off originally. And I check the tire pressure before every outing, front is 28 and back is 36 PSI cold.

When we "fill" up Rosie, it is about 1.7 gallons and the tank is factory, so that WTF, mate?

Thanks,

greg

 

Re: 75 miles and then gotta got reserve?

40 * 1.7 = 68 so 75 sounds about right.

When you fill up after 75 miles it's taking how many gallons?

I think somewhere your math is off.

 

That is eactly what I am saying. I top off the tank, she rides for about 75 miles, has to go into reserve, and we then put about 1.7 gallons back in.

She should be able to go 100 miles or better before she needs to go into reserve.

At 40MPG, and a 3 gallon tank, she should, ideally, go 120 miles before she needs to go into reserve, but at 75 miles, she acts like she is running out of fuel, SWMBO flips to reserve and off she goes.

So, my math is good, the bike is good, but something is not adding up...

 

is your internal petcock screen dirty? maybe the bottom of it is clogged up and can't flow fuel properly. A switch to reserve would draw the fuel lower and bypass the clog.

 

Hmmm, maybe!

I guess I will have to drain the tank, and pull the petcocks, and see if there might be some paint flakes trapped on the screens.

I had the tank painted back in December, by my local MAACO. Won't do that again...

I'll report back.

Thanks for the suggestion!

greg

 

you've got the wrong fuel switch. or someone changed the tube becuase it's too high.

2.5 gallons is what you should get before hitting reserve. total tank is 3.4 gallons. leaving .9 for reserve.

 

Interesting theory, Snowwy66. I bought those petcocks, new, and they are OEM, from Bike Bandit, or Babbittsonline, I can't remember..

The screens looked the same as the old ones.

I haven't pulled them out yet. I asked SWMBO if she could burn off some more fuel today, so I didn't have so much fuel to drain. But, she is afraid of running out... If I had a dime for every time I ran out...LOL

I should have ridden Rosie to work, this morning, and left the Scorpion at home, but didn't. Of course, it's only a 5 mile ride to work, so I wouldn't have burned too much fuel anyway...

I'll report back.

 

the screens may look the same but how's the tube height. cuz that's why you can't suck down as far. i bet if you cut an inch off the tube. youi'd go a lot farther before hitting reserve.

 

Re: 75 miles and then gotta go to reserve? ** Update **

OK, so I pulled the petcock yesterday, and compared it to the original.

I noticed something interesting... Here is the pic I took of both petcocks, old on the left, new on the right:



I wonder if the tubes are in the wrong holes? I ask that because if you look at the old one, the reserve draw is on the right, On is on the left and up top.

On the new one, it looks like the reserve is drawing from the left and the On is drawing from the right.

I guess I'll have to pull it again and look at the paths, and see if they are in the right holes...

Any thoughts?

 

Is your tank original?

I won't swear to it but, my bike has 2.5 gallon tank.

It looks like we have the same bike.

 

Those are two entirely different Petcocks.

You cannot compare the two for how they function.

Pull the Filter Tower out from the one on the Left.
There should a two Inlets for Fuel with different diameters.
The Filter should be made with a connecting pipe that prevents it being installed incorrectly.

 

Yes, it is an original tank. Not the one that came with the bike, but it is the same year and size.

The manual says 3.4 US gal. and 0.8 US gal. reserve.

So, if I take 0.8 from 3.4, I get 2.6 US gal. for the main. And if I get 40 MPG, then I can expect to go 104 miles before I have to switch to reserve, in theory.

And, in reserve I should be able to go another 32 miles before I run out of fuel, in theory.

 

Yes, Rick, you are correct. I can only put the screen one way, on the old petcock.

And this new petcock is the OEM replacement, from Yamaha. The box in the background is the box it came in. That is the number that superceded the original number.

 

The "New" Petcock does not look like it's designed for a Horizontal placement.
Horizontally, you need to switch to reserve after only a small percentage of fuel use.

In some other position, ... approaching a slanted installation would increase the volume of fuel used before the necessity of switching to reserve was necessary.

So, ...
There looks like some mistake was made.
The "New" petcock is not a suitable replacement.

You might have a situation where you bought the "Right" box with the "Right" Bar Code and the "Right" Part Number, ...

But, ... what was IN the Box was the WRONG Petcock!!

 

If you look at the hieght of the new tower filter, you will see that it's 32 miles higher.

 

the microfiche parts list switch looks like the one on the left.

don't know about others. but the one on the right is what i have in my tank. although i think the screens are reversed. would have to pull down again to check and right now i've got full tank. but i'm defenitly getting 2.5 gallons on main.

could you post a pic of the bottom of that new switch please. cuz the bottom of mine defenitely ain't the one on the left. mine is a solid bottom. but the outlet tube is broke or something and just spins around in the hole. i have jb weld on it to hold in place and to keep it from leaking.

 

You could be 100% correct, Rick. I may call the vendor next week and ask.

Wiz, I see your point! That could very well be true!

And Snowy, SWMBO too has a full tank, so I will have to wait for her to empty it before I can get you some good pics.

Since I rebuilt the original petcock, before I bought the replacement, I may put it back and see how it behaves.

I'll post back when I get so more information.

Thanks, for the insights!

 

what's this SWMBO crap?

 

The one in the Box looks more like the Petcock that was OEM on the
1993 Seca II 600.

 

I had to google that one too... "She Who Must Be Obeyed." AKA: the wifey, girlfriend, old lady, ho, you get the idea.

 

maybe it's been discontinued rick? or replaced with an updated part number which happens to be the seca switch. cuz the one on the right is exactly what i've got in my tank. and i have no idea when it was installed.

 

I've been following this thread all along, and thought that the primary tube must be longer, and the photo explains it. What's the difference between 'ON' and "primary"? I usually go 115 miles and add 2.5 gallons, for 46 MPG.

 

ON = Gas supply flows from Petcock when Manifold Vacuum opens Vacuum-operated On-Off valve.

PRI = Petcock is Opened to continuous flow. No Vacuum necessary.

 

This is a really simple problem.

It doesn't matter that the "towers" look different on the two petcocks, or that they are in different places. As long as the tall tower (or tall side of the tower on the OEM petcock tower) is accessed under "ON" and the short tower is accessed under "PRI" they are functionally equivalent....with one exception.

It is noticeable in the picture, and clear from the description of the problem that the blocked off part of the tall tower is too high! The problem is easily remedied, however.

Gas flows in through the screens, but not through the plastic piping. On the new petcock, that piping looks to be about .5 in taller than on the old one.

I would bet that at that point in your tank, that half inch of height holds exactly the difference between the 1.7 gal you are getting, and the 2.5 gal you should be getting.

Remember, the tank is split at one point, and fattest at one point. I bet that is before it is split but at its fattest point. Thus allowing .8 gallons in that .5 to 1" of petcock height.

Solution: Well, since you already have a inline fuel filter (or will have one if you do this, you will), why do you need the fuel filter on your petcock? Just cut off the top of the tall tower to the height you want.

Done and done.....

 

It's the wrong Petcock.
It's the wrong Part.
One is and Apple
The other is an Orange.

The solution is not to ruin a perfectly-good, brand-new part and open the door to a possible fuel supply interruption.

The solution is to put it back in the box.
Bring the box and the old one to the stupid person who sent the wrong part.

(Oh, I'm sorry, ... I shouldn't have called that person stupid. That was an insult to REALLY stupid people.)

Take command.
Return the wrong part.
Demand your money back.
Don't take "NO" for answer.

 

I agree with rick-o-matic....Get what you paid for...

 

The part you have does appear to be improperly restocked (or another customer did a switcheroo) with a 1982 XJ650LJ petcock. The part number on the box is for the XJ650J petcock.

If they try to charge you a 20-25% restocking fee plus shipping for the return, costing you $16-20 plus shipping, I personally would cut it. And not purchase from them ever again. And let everyone here know.

And email them a link to this post so they know they will be losing over 7,000 potential customers if they do you dirty.

Let us know how it turns out.

Rick...good catch. I'll debate you as to whether 2 fuel filters are needed at a later time. I'm in too good of a mood right now.

If I had that style of petcock it would already be cut. I think having 26.47% of your tank as a reserve is ridiculous (my car is at 13.75% which would give about 20 miles of reserve time), but there's nothing I can do about it comfortably because the two towers are so close together and I don't want to mess up having a reserve at all!