Reason for fuel pump delete

[ACEMUSTANG2002]

I still have a fuel pump and have seen mentions of deleting it. What benefits are there with deleting it? I have a Mikuni flat slide carb if that makes a difference

[Brad_G]

Many will do it to clean up the left side of the bike for aesthetic reasons. The other is that it eliminates a potential point of failure. Carb motorcycles have run for many many decades using just gravity.

[davej]

1 of the reasons they used a pump on our bikes is due to the small fuel bowl capacity and in some riding conditions it could potentially use all the fuel in the bowl quicker than gravity can fill it.

[Brad_G]

Thanks davej for that explanation. I presumed Yamaha engineers figured there was value or they wouldn't have put it on and saved a couple bucks.

[roadiemort]

Although venting the cap could become a safety issue in a spill for those that did so.

[davej]

no real reason but many will tell you that it is 1 less thing to go wrong. some just remove the pump and never have an issue, others remove the pump and have issues and need to change the float valve and vent the tank and some even have to adjust the float. some have to switch to reserve at 1/4 tank or so. some of those issues are only on the oem carb. I deleted the pump using a HSR42 flat slide and had running of of gas issue at 1/4 tank and had to go to reserve. I sold the carb because of that and a couple other issues I didn't like, like venting the cap. I installed a big bore kit on my bike and had to use a flat slide carb so I left the fuel pump on and changed the float valve to a smaller valve for using a pump and never had another issue with any of the other problems. Short answer is there really isn't a reason to remove it. But if you have tinkeritis you may want to give it a try.

[ACEMUSTANG2002]

I think I’ll keep it on. I like having the confidence of positive fuel pressure and it doesn’t seem that expensive to replace if it fails. I’d like to do the big bore kit eventually. Might pick up another engine to do it so I can keep riding…

[Duke]

I've always had tinkeritis and beleave in the KISS theory. I do like the idea of having 1 less amp being drawn from the electrical system, shaving off 1.4 lbs., a little more air around the jugs, and not having to rely on a pump. I know it's not much, but it all adds up. I personally haven't had any problems with gravity feeding the carbs.
The stock tank venting is just fine when the bikes are new, but give it 5, 10, or 15 years, the check valve, "rollover valve", will fail if not having any maintenance done to it. Rollover valves going for $80.00 a pop, or just pitching them in the trash? I think I'll pick the trash can and go for a $1.25 hose nipple.
Venting the tank fuel cap Is not a option for me, because I don't like fuel on my lap after fueling up.

[Shotround]

is there any other way to vent the tank if that nipple is rusted shut? i blasted it with air when i filled the tank with evaporust last year.

[Duke]

On one of my tanks, the tank vent nipple had clogged up, so what I did was to use a 3/32" drill bit and drilled thru the vent nipple at the 90* bend, down thru into the tank. The tank part is hard steel so I used a Colbalt drill bit, drilling carefully. When you attach the vent hose, just run the hose passed the hole in the nipple.

[Shotround]

that's genius.

[Kurf]

There seem to be no roll over valves on my bike… can it be it was not original on european bikes?
It is a 1600 from 2000…..
Maybe a previous owner already removed it?

[davej]

probably has been removed. It is there for safety in the event of a laydown of the bike. it keeps fuel from leaking out of the small tank vent tube.

[Kurf]

Thanx

[Ratl]

There are so many Roadstar owners that have ditched the pump with no fuel starvation issues, ever, when it is done right. When you do anything halfway, that’s the kind of results you get, halfway. Anyone who’s had ‘issues’, did a halfway job. Do it right once, or keep doing it ‘til you do it right,

Reasons why:

• Aesthetics. Absolutely. All of that junk on the left side gets tossed and the jugs look great without it.
• My pump failed at 18,000 and left me stranded on the road for a day. I spent less to properly go pumpless and gravity has never failed anyone yet.
• ”carb puking”. Roadstars with the pump will leak gas all over the bike on hot days due to the buildup of pressure in the fuel line between the pump and carb. The fuel cannot go back into the tank through the pump, so it forces its way past the float valve and out. Roadstars have gone up in flames because of this! Going pumpless eliminates the ‘puking’ issue.
• If you’ve done it right, (which include cutting down the main petcock tube slightly), you don’t have an issue with having to switch to auxiliary early.
• ‘Your bike will run cooler with the jugs opened up.
• While you have the carb off, you might as well port the manifold. :-)

Just because Yamaha built it that way doesn’t mean it was better or needed. If either of those were true, I and the many others wouldn’t be doing it. Manufacturers are constantly changing designs to improve the product, otherwise they would all still be carbureted. We can make improvements too!

Ratl.

[brianmac]

its has become quite a fad for some, but , i prefer to relocate the pump. if i forget to turn back on the petcock, the pump affords instant start, a HUGE safety factor for me. standard practice is to have 3 foot of fuel line in saddlebag, never needed it tho, on 4 RSs

[Ratl]

When you go pumpless, you no longer need o turn off the petcock. Turning off the petcock was an attempt to reduce carb ‘puking’ due to the pump not allowing fuel back into the tank when the fuel lines get hot. I know, because I used to have to do it shortly before turning off the motor to reduce the amount of fuel in the bowl, to try to prevent ‘puking’. So, no need to worry about that ‘safety’ issue.

If the pumps such a good idea, why carry fuel line to go pumpless when the pump fails?

[brianmac]

QUOTE "When you go pumpless, you no longer need o turn off the petcock. Turning off the petcock was an attempt to reduce carb ‘puking’ due to the pump not allowing fuel back into the tank when the fuel lines get hot. I know, because I used to have to do it shortly before turning off the motor to reduce the amount of fuel in the bowl, to try to prevent ‘puking’. So, no need to worry about that ‘safety’ issue.
If the pumps such a good idea, why carry fuel line to go pumpless when the pump fails?"
ANSWER:
Ratl,
turning off the cock is a home safety issue. many instances of shat in float bowl, or oring or rubber tip failure, lead to pool of gas on floor of garage. i have a gas water heater in my garage. and 3 RSs. u can bet all their cocks are off, just like bike shops and dealers if they want to follow insurance regs and be paid in an event of fire.

we carry gas line, in case pump fails badly enuf, just bypass it and limp home. real men dont call a tow truck, even when clutch cable snaps.

ever drive a bike down the road to get home, when gas was spewing all over your leg due to flooding? thats when u turn cock off 1000 yds B4 red lights. and bring a set of sparker pluggers and a handy wrench with ya. (this one had non visible to naked eye pinholes in the brass floats!

[Ratl]

Your response to turning off the petcock has drifted far away from and is unrelated to the topic of ‘why pumpless’. Carb puke is well known and common issue with carbureted Roadstars that have a pump and is the reason most of us had to turn off the petcock a short distance before turning off our bikes. Yes, for safety, because of carb puke.

You don’t need to carry fuel line to go temporarily pumpless if you just ditch the unnecessary pump and go permanently pumpless.

I’m not telling everyone to switch just to switch, but when your pump fails you, and it will, why pay the high price if replacing a part that will eventually fail again. Gravity won’t fail you. Keep it simple.

Like I said, fix it right once, or keep fixing it until you do it right.

[brianmac]

PS, most non fuel injected "newer bikes" have electric fuel pumps, vstars, shadows, VTXs, Vulcans etc, my thought is liability ?