getting rid of vacuum fuel pump?? By serpic0 (Read 2,012 times)

[serpic0]

Hey all:

Can someone tell me if it is beneficial to switch to an electric pump?? and if so what one are you using and how did you wire it up?? the reason I ask this is with the last scooter I had a Roketa Bali it had the gas tank under the seat so it didn't have a fuel pump, so when I backed off the throttle it didn't feel like it was going to die like it does now with this Propel that has a pump and fuel tank up front. I guess I could have a vacuum leak, but what do you guys think? thanks
tl

[Alleyoop]

My trike must be just like yours my tank is up front and I have a Vacuum pump and the pump pumps the gas UP to my carb and it almost 4 feet away to my carb. It works just fine and it actually has to pump it up to the carb from down by the bottom of the frame.

But what is your current problem, from what you sort of indicated is that it wants to die when you let go of the throttle and it comes down to IDLE, is that correct? What exactly does it do and when?
Alleyoop

[serpic0]

Well for one in the morning it is very hard to start have to grind away before it fires, after that it starts at the touch of the starter button, so I am thinking maybe I have a vacuum leak as the gas in the lines drain down at night so it takes awhile to get gas back up to the carb? and when I am traveling down the road say 45mph and coming up to a stop I back off the throttle and coast and at that point it feels like it wants to stall, like it has run out of gas, if I give it a little throttle it is fine so my guess is that when I let off of the throttle I lose vacuum and then I lose fuel, am I on the right track??, maybe this is normal for a fuel pump scoot as my other one never did this (no fuel pump),or maybe I need a vacuum canister to keep vacuum in the engine on deceleration, or like most things am I over thinking this?? thanks Ally for the reply..

[Bashan]

My Pegasus was running the bowl dry so I made these mods. I replaced the vacuum petcock with a brass fitting:

Here's the Mr. Gasket electric pump, included filter, and B & S manual valve. You can see I also put in my own post pump filter:

here's the 1/4" to 3/16" reducer I made to scale down to carb inlet size:

Then I wired it to the black ignition wire so that it would come on with the key.

It works great and no more bowl running dry.

[Alleyoop]

All that is pretty and what not RICH BUT that is not his problem AT ALL(Over thinking the problem here). From what he just said its his VALVES. The valves need to be adjusted he is loosing compression and low on vacuum. HARD STARTS WANTING TO DIE coming down to IDLE CLASSIC SYMPTOMS.
Alleyoop

[serpic0]

Ok I have adjusted the valves last year as per the recommendation's on here, maybe I have to do it over again then, but I figured it was running good after it starts, and I can go out there now and it will start right up, so your saying that the valves being out of adjustment will make it hard to cold start, and feel like it is running our of gas on deceleration?? we'll I'll reset the valves and report back thanks for the replys..

[jct842]

I will take a vacuum fuel pump any day. For one thing it is safer. Any time the ign. is on the electric is pumping. A fuel leak and a delay in starting after turning the key could be a way for a fire. And if it happens in a garage and you jump away instead of reaching for the key thru the flames....poof there goes the garage.

[Alleyoop]

And John is right a ELECTRIC PUMP on this motors is overkill and you really have to pay attention because as soon as you turn the key on the pump is pumping. And if you have a hard starting motor that needs a lot of cranking guess what you will flood it really quick.

Well here is the thing Serpico, on Decel the vacuum is the strongest and you should have ACV valve on that carb looks like a flying saucer near the top of the carb. That should have a VACUUM line and another hose from ther to the right side of the carb. Now what that does is when you let go of the throttle at that point the butterfly snaps shut and the rpms have not yet gone down and it will run really LEAN. But the ACV valve as soon as the butterfly is closed and the motor is making a lot of vacuum opens the ACV valve and sucks in gas so it does not run lean on you.

Now also a LOW IDLE will cause it to also run lean the 250s the idle should be set 1800-2000 rpms if set lower it has a chance to die on decel and also create hard starting.

But I always recommend checking the VALVES first and adjusting them BEFORE trying to compensate by adjusting the carb. You may get it to run better but it will get worse and then you will AGAIN have to re-adjust the carb after the valve adjustment.
Alleyoop

[Bashan]

May 22, 2014 23:04:02 GMT -6 serpic0 said:

Can someone tell me if it is beneficial to switch to an electric pump?? and if so what one are you using and how did you wire it up??

He asked and I answered. Anyway, it gave me a chance to show off, you know how much I like doing that!

[Alleyoop]

I know you do take great pictures and very clear. Just giving you snit is all don't want this to go to your head to much

[Bashan]

I know pal, no offense, just goofin', you know me. Rich

[serpic0]

Ok Guys so I worked on adjusting the valves for over an hour, not sure how long it is supposed to take but that's how long it took me and now this morning it wont start at all, and after cranking for a while and it didn't start I gave it some throttle and then I could smell gas so I know I am getting gas, now when you guys adjust the valves you are supposed to do it AFTER it is all warmed up right? guess I will go and look at the procedure again I must be doing something wrong, after adjusting them last night it ran really nice had nice pickup no backfireing, I don't get it, but I will I keep trying stuff till I get it running...

[Bashan]

Nope, you set them cold. Did you check out the valve set tutorials in the Library under engine?

[serpic0]

nope I have a Honda clone not the Yamaha, so you don't use a feeler gauge to set them, the tutorial on here from Honda says to set them warm, I just re-Read it, I must have something else going on under there.....

[Alleyoop]

are you valve adjusters on the outside on the LEFT side of your valve cover? if so then yes you set them while the motor is running actually, just like you would on the old cars.
Alleyoop