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Discussion Starter · #1 ·
My question is about running a big fuel pump vs. the one I have now. I have been chasing a fuel issues for a bit now.

I am running a 330cc with a 44mm alky lectron. The pump (mukuni) I started out with was a 35 lph, after some testing I tried a 14 lph pump and my problems got worse so I took the 14 off and went back to my 35 lph pump but when I am at the starting line and I bring the revs up to launch the quad, the engine just doesn't "feel" right, its kinda hard to explain......lol

My question is will I hurt any thing if I try a 65 lph pump on my litte 330cc? will it be to much pump for my engine? Any advice would be appreciated. Thanks in advance
 

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Discussion Starter · #2 ·
sorry forgot to post that my carb already has the big billet float bowl, gas tank pet[censored] has been gutted and gas tank cap has been drilled out.

I am running 1/8th mile asphalt
 

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well we run the Mikuni/FTZ modified fuel pumps on our stuff......with the billet bowl, and a pingle valve. I have never ran out of fuel with this combination.... we run sand mountain, its 700 ft with a steep grade. I know the aeromotive pump flows alot f fuel as well, bobby is using this on his Nitrous bike, but it may be too much for you motor??? We ran my 370 and it likes alot of fuel memorial weekend and never ran it outta fuel. 86 the 14lpg pump, they are junk...... for your application anyways, been there, done that!
 

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Discussion Starter · #4 ·
when i am running on the asphalt I have to run my P/J at a very minumin of 6 turns out or it will burn the ground strap of my spark plug. My P/J only opens to a max of 6 3/4 turns out.
I am not really sure if I need another P/J added or its my fuel pump I have know (35 lph) that can't keep up with the fuel demands of the engine.
 

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Discussion Starter · #6 ·
I bought the carb from Packard, thats why I am kinda leaning towards a pump issue instead of it being a carb issue. I am not sure if the 35 lph pump I have now is feeding my engine sufficiently, my engine seems to want as much fuel as I can stuff into it.

Has any one run a 65 lph pump on a single cylinder?

any help or advice anyone can offer would be appreciated
 

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we had to drill the PJ out 3 times on my 370. its a lectron set up by Dennis.......Some motors just require to run more fuel. Alot of it has to do with head design.....Id try drilling your PJ out some, see if that helps..... how hot does your motor run??? Who built the motor, what ignition, pipe....give us some details....
 

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Discussion Starter · #8 ·
QUOTE (blasterman88 @ Jun 10 2008, 07:00 PM) index.php?act=findpost&pid=2418we had to drill the PJ out 3 times on my 370. its a lectron set up by Dennis.......Some motors just require to run more fuel. Alot of it has to do with head design.....Id try drilling your PJ out some, see if that helps..... how hot does your motor run??? Who built the motor, what ignition, pipe....give us some details....

OK here is the whole low down on my set up: 72mm stroke 330cc
porting done by packard set up to run alky
shearer oof pipe
2001 CR ignition
custom dome by RK Tek (static comp 210psi)
44mm alky lectron set up by Packard (with billet big bowl)

My quad only races on 1/8th mile asphalt

On warm to hot days cylinder tends to run on the "warm" side which tells me I am lacking enough fuel (I think?)

When I am not burning the ground straps off my plug, it seems to pull pretty hard, usually cooler temp days.

how do i drill out my P/J? what size drill bits do I use? My P/J has a "bell" on the end of it.

Thanks for all the help guys, I really appreciate it
 

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based on the info you have given...i think you need to drill that PJ....i attached a pic...i think this is the piece you grab with a pair of pliers and loosen, the whole needle and everything will come out of the tube.....get your self an index drill bit set and start putting bits in the tube to see what size it is... you may want to go 2 drill bit sizes bigger since you are all the way out on your PJ and its still a little lean....ill leave that up to you, remember you can always drill more if needed.... once you have the needle out you drill from the top, so the bell isnt an issue....
 

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QUOTE (Asphalt330R @ Jun 10 2008, 05:43 PM) index.php?act=findpost&pid=2427OK here is the whole low down on my set up: 72mm stroke 330cc
porting done by packard set up to run alky
shearer oof pipe
2001 CR ignition
custom dome by RK Tek (static comp 210psi)
44mm alky lectron set up by Packard (with billet big bowl)

My quad only races on 1/8th mile asphalt

On warm to hot days cylinder tends to run on the "warm" side which tells me I am lacking enough fuel (I think?)

When I am not burning the ground straps off my plug, it seems to pull pretty hard, usually cooler temp days.

how do i drill out my P/J? what size drill bits do I use? My P/J has a "bell" on the end of it.

Thanks for all the help guys, I really appreciate it 330r sounds like you need another needle so you don't have to Max out your power jet or put in another power jet and leave one maxed out and tune with the second ,it wold not hurt to have a bigger pump all so , if you put a bigger pump first and it runs rich with the same carb settings you have now ,you fond the problem , but if it still lens out you will need to do 1 of the 2 above the pump will work fine it does not mater if it pumps 100lpg as long as its at low pressure
 

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QUOTE (Asphalt330R @ Jun 10 2008, 06:43 PM) index.php?act=findpost&pid=2427OK here is the whole low down on my set up: 72mm stroke 330cc
porting done by packard set up to run alky
shearer oof pipe
2001 CR ignition
custom dome by RK Tek (static comp 210psi)
44mm alky lectron set up by Packard (with billet big bowl)

My quad only races on 1/8th mile asphalt

On warm to hot days cylinder tends to run on the "warm" side which tells me I am lacking enough fuel (I think?)

When I am not burning the ground straps off my plug, it seems to pull pretty hard, usually cooler temp days.

how do i drill out my P/J? what size drill bits do I use? My P/J has a "bell" on the end of it.

Thanks for all the help guys, I really appreciate it








just in case you did not know, the needle on the lectron carb will screw in much farther once the threads disaper out of sight into the base of the slide. just keep pusting the needle in to feel the spring sensation to find out when you have bottomed.....you dont want to strip out the plastic nut the needle screws into!
i ran a 19-4XL on my 44 and 38-40HV. (19-4 is an alky needle)


i just got my needle for a 48 today. its a PE-7. it looks 100% different than a 19-4xl. the pe-7 has been grooved out...or rather has a radius made into the last 3/4 inch [that is normally flat but angled to a point to the tip then it blends into the taper] thats milled on the needle.



the aeromotive pump i run is strictly for the nitrous only.
i have the same pump that blasterman88 described running my carb. ftz alky mikuni pump. lol, they never wear out! been running the same pump now for 8 years!!!!!!
o and btw that mikuni pump will make 3lbs of pressure under acceleration. it wont make any pressure just pinning the gas wide open. matter of fact i'll bet you can drain your float bowel in over rev due to the fact that the engine is not creating any pulses. this mikinu pump is like a blocked fuel line under them conditions.
just thought you might like to know that. i would bet that ANY pulse pump would act the same in a non pulsation condition. (over rev or just bringing up the revvs)
 

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Discussion Starter · #13 ·
QUOTE (turbo bobby @ Jun 10 2008, 11:37 PM) index.php?act=findpost&pid=2474o and btw that mikuni pump will make 3lbs of pressure under acceleration. it wont make any pressure just pinning the gas wide open. matter of fact i'll bet you can drain your float bowel in over rev due to the fact that the engine is not creating any pulses. this mikinu pump is like a blocked fuel line under them conditions.
just thought you might like to know that. i would bet that ANY pulse pump would act the same in a non pulsation condition. (over rev or just bringing up the revvs)


I just want to make sure I understand what you are saying, are you saying that the fuel pump basicly doesn't do its job unless it see a "load" from the engine?

when I pull into the staging lane, and once I trip the 2nd stage light on, I bring the throttle up to 1/2 and then full throttle once I drop the clutch. Am I draining the float bowl dry cause the fuel pump doesn't "see" an actual load on the engine?

Thanks to all who have helped me on this issue
 

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Turbo, is this a Honda thing, or a placement of the vacuum/pulse line thing?

I tap the intake of my cub, after the cages, and I get pulse with or without load.
I know this because when I purge and rev it up, it will suck fuel much faster compared to lower RPMs. If there was no pulse, it would be the same no matter what the RPM. (and by rev up I mean 1/4 throttle, not WOT...until it starts running on gas again from purge)

Also, when I had an issue with a piece of metal in the needle/seat and it wasn't sealing correctly (my bad, stripped a seat a little) when I rev'd it up in nuetral, it spit fuel out faster out the overflow tube. Instead of a trickle from not being able to seal, it was like someone turned a faucet on....
 

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I am telling it how I see it. I have a duel feed pingle on this bike (Terrys old airforceone rigid yfz450).
I had one line going straight to the mikuni pump and from there to the mikuni carb. The other line went right to the electric fuel pump. What I did to check the fuel pressure was just pull the line off the electric pump and connect it directly to the carb. This left my mikuni pump out-put open to connect straight into my autometer 0 - 15 psi liquid filled gage. All I was doing at the time was checking out the psi out-put of all my pumps. The Mr Gasket solenoid style pump only did 4psi. The aeromotive did 7.5 psi and just for 'giggles' I checked the mikuni pump. It didn't register anything idling but if I bumped the gas it would go to 3 psi and fall back off to something under 2 pounds. the gage is not accurate under 3 psi.
I do know that holding the gas at 5000rpm no load the psi was under 2 psi. Does that mean the pump is not pumping????? I don't know.....however, just holding the R's at a given launch rpm...... like 8000 rpm with no RPM limiting 'studder' could suck the bowl dry in my opinion, on a honda single cylinder, once again, this is just my opinion.
I pull my signal from the rear transfer port. Heres a pic just for reference.
Picture_228.jpg


Heres a camera pic of my gage. pic061208_1.jpg
 
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