Petcock filter direction

[Bartman]

My bike gets around 40mpg on average. But I have to put on prime a little before 150 miles and then a refill before 170 or it has that "about to run out of gas" feel. For the last year the most that I can put in it is 4 gallons. (Standard tank)

I got to thinking about it and wonder if I put one or both internal petcock filters on reversed.

The next time I am at 150 miles I think I will only turn one petcock at the time to prime and see if that can lead me to the problem if that is it.

Or does anyone have another idea? In a week or two I will take off the tank and take pictures of them.

[IanDMacDonald]

I'm more interested in your jetting and setup, allowing you to see 40 mpg, lol. Please share.

[Bartman]

I have factory air box and exhaust. The pilot jet is a 45. The pilot air is a 210. The main jet is a 140. The guy that I got all of the parts from said that some of the early bikes had this bigger main jet.

Once cleaned and working it had a slight bog when giving it the gas. I finally figured it was between the pilot and mid range and lowered the needle down one click.

Now cranks easy, runs good from slow to max and can putt in the parking lot in first, second or third gear with plenty of smooth power.

Last weekend road to the Ga. Mountains and 166 miles and 3.8 gallons = 43.68MPG. And I was pushing it up and over the hills!

[natemoen]

If you had put the screens on backwards then you would have no reserve. if they ere on backwards when you would hit reserve you would already be basically empty.

Plus, the way they are designed they can't be put on backwards.

[IanDMacDonald]

I have factory air box and exhaust. The pilot jet is a 45. The pilot air is a 210. The main jet is a 140. The guy that I got all of the parts from said that some of the early bikes had this bigger main jet.

Once cleaned and working it had a slight bog when giving it the gas. I finally figured it was between the pilot and mid range and lowered the needle down one click.

Now cranks easy, runs good from slow to max and can putt in the parking lot in first, second or third gear with plenty of smooth power.

Last weekend road to the Ga. Mountains and 166 miles and 3.8 gallons = 43.68MPG. And I was pushing it up and over the hills!

Just curious as-to where you got the 3.8 gal figure from?

[DiverRay]

Reading his post, he put 3.8 gallons to fill it back up after a 166 mile ride, hence the 43.68mpg.

[Bartman]

I keep thinking that one side is wrong and it doesn't allow any reserve as stated and hence is running out on that side.

I assume that I have the correct petcocks. I was looking at another post with pictures and it showed that the filter had a small post for alignment. But mine just have a double barrel hole in the metal and I think that the filter can be swapped.

It will be a few days before I can tear into it. I'll take pictures when I do.

[Bartman]

I reread an earlier post, so here are some questions.

How many miles do you go before you put your bike on reserve?

Or when you put you bike on reserve, how many gallons does it take to fill up?

[IanDMacDonald]

I reread an earlier post, so here are some questions.

How many miles do you go before you put your bike on reserve?

Or when you put you bike on reserve, how many gallons does it take to fill up?

That question is opening a can of worms, as every bike is different, contingent on fuel consumption. Mother Yammy says the Standard has a 5.3 gal. tank. Forum members rely on it being a 4 gal. tank, with a 1 gal. reserve. The Special is claimed on here to be a 4-gallon tank, (3+1). I have horrible mileage right now, so you can't ask me. But, I can tell you that you are definitely above the norm on fuel mileage. Most members report 30-35. My Hayabusa gets 34mpg, and it's fuel injected.

However, I will once and for all answer this question for myself, and carry extra fuel prior to the riding season and run her dry. My only question is: AT WHAT POINT DOES YAMAHA SAY IT'S FULL? Cuz, I fill that neck up to the point where any drop more, and it spills.

[red bandit]

FWIW I get 39 mpg on my 79f, full bagger, I hit reserve at 155 miles on the odometer. That's with being somewhat easy on the throttle. Depending on how much I twist the throttle it may go as low as 32 mpg. It sounds like you have things set pretty good. If your set up was using your reserve you would get closer to 200 + miles per fill up with no reserve. MHO.

[jetmechmarty]

1/3 gallon in your tank bag could make all the difference, especially if you ride a Special.

[Bartman]

So I was thinking about this today and have another question.

When you put your reserve on, does your bike run good until it is out of gas?

Mine runs ok for a few miles and then starts the bucking.

Last weekend I put mine on reserve at 155 miles, not because it was bucking, but because I knew it was mileage time to be thinking about it. Then at 165 miles I was a mile away from the gas station when it started to buck. I was surprised at only 3.8 gal. to fill up.

Makes me remember last year when it was "low" on gas and died on me and I had to walk three miles home. Looking in the tank it sloshed gas so I wasn't truely empty. I Thought I had a real problem. Once I trailered it back home and checked may things did I put gas in it and it cranked up. So course by that time I had fiddled with several things and wondered if it was just out of gas. But when you put a gallon or two from the mower and then fill up at the station, you can't really know how much went in.

[IanDMacDonald]

I'm wondering if your petcocks are performing right? Once I have my bike tuned with the smaller jets, I'll hope for an increase in fuel mileage and test how far the bike will go.

[jetmechmarty]

Is the fuel cap venting properly?

[Bartman]

Gas cap was taken apart, cleaned and I drilled an extra small hole. Should not be the problem. I think that I have opened it during the year when verifying too.