Fuel delivery problem (fixed) now popoff problem?

yamanube

yamanube

This Is The Way
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Mandalor
Got my new motor in and running but I dont seem to be getting fuel into the carb. Ive got all the lines routed correctly, tank check valve works and the pulse line seems to have a nice strong signal. I pulled the carb apart and everthing looked intact and clean.
When I crank it over it pulls fuel about halfway through the line then starts to bubble back and just flows back into the tank. (I think)
61x 701 with Riva Powerbomb.
 
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Andrew1289

Andrew1289

Hey, someone smarter and more experienced than me will chime in here but...

If you got your motor in and RUNNING then its getting fuel, if its enough I dont know.

If you had to take your motor out for some reason and put it back in and let gas sit in the tank or whatever maybe its gummed something up. If you have a primer, and when u prime it and no fuel gets the the carb, somthings clogged. Check it in parts (carb to fuel filter/ filter to tank....) Blow through one end to see if it clogged.

One guess, take apart your fuel pick up. (its easy) and there is a small brass (i think) fitting/jet looking thing at the end. Try to blow through it, if its clogged use carb cleaner to spray it or try and push somthing through like a paper clip untill you can blow through it.

good luck.
 
yamanube

yamanube

This Is The Way
Staff member
Location
Mandalor
Andrew1289 said:
Hey, someone smarter and more experienced than me will chime in here but...

If you got your motor in and RUNNING then its getting fuel, if its enough I dont know.

If you had to take your motor out for some reason and put it back in and let gas sit in the tank or whatever maybe its gummed something up. If you have a primer, and when u prime it and no fuel gets the the carb, somthings clogged. Check it in parts (carb to fuel filter/ filter to tank....) Blow through one end to see if it clogged.

One guess, take apart your fuel pick up. (its easy) and there is a small brass (i think) fitting/jet looking thing at the end. Try to blow through it, if its clogged use carb cleaner to spray it or try and push somthing through like a paper clip untill you can blow through it.

good luck.
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Sorry I was a little vague, I can give it a couple shots from the primer and it runs but will not pull fuel. The ski was running 2 weeks ago any my motor blew up, I pulled it apart and bought a new motor. Just re assembled the ski with the same carb and now this.
 
Mark44

Mark44

Katie's Boss
Location
100% one place
Retrace your steps bypass the fuel selector check to make sure the lines are connected the correct way on the carbs.

I would have to bet it will something silly like that if the carbs ran fine beforehand.

Did you disassemble the carbs for a rebuild?

Mark44
 
yamanube

yamanube

This Is The Way
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Location
Mandalor
Mark44 said:
Retrace your steps bypass the fuel selector check to make sure the lines are connected the correct way on the carbs.

I would have to bet it will something silly like that if the carbs ran fine beforehand.

Did you disassemble the carbs for a rebuild?

Mark44
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No fuel selector, just plumbed off the tank, through a filter and into the carb. I quadruple checked to make sure all lines where hooked up correctly. I disassembled the carb to rejet for the new motor and once again after this problem to make sure everything looked good, pulled the pump side apart the second time...there was a little grit in the internal filter that I cleaned out and blew out, all diaphrams looked good, no cracking or rips.
 
SuperJETT

SuperJETT

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Prime the carb, pull the flame arrestor and put your hand on the carb to block it completely of air, then crank it. The engine will suck fuel through and fill the carb circuits and it'll try to fire. As soon as it tries to fire, pull your hand and get it started.

If that doesn't fix it, then you need to pull everything apart again and double check everything. No crimps in the fuel pump check valves, lines hooked up properly, no blockages anywhere, etc etc.
 
yamanube

yamanube

This Is The Way
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Location
Mandalor
SuperJETT said:
Prime the carb, pull the flame arrestor and put your hand on the carb to block it completely of air, then crank it. The engine will suck fuel through and fill the carb circuits and it'll try to fire. As soon as it tries to fire, pull your hand and get it started.

If that doesn't fix it, then you need to pull everything apart again and double check everything. No crimps in the fuel pump check valves, lines hooked up properly, no blockages anywhere, etc etc.
Click to expand...


Didn't try choking it....Ill check that tonight. If that doesnt work Ill pull it back apart and tripple check the internals.
Also, when I blew up my motor, we also sunk it on the way in :doh: I pulled it all apart as soon as I got home and disassembled the carb and bunch of water poured out but again everything looks just fine now.
 
Wave Chaser

Wave Chaser

Location
League City, TX
I might be pointing out the obvious but have you tried priming the line by pulling the return off the carb end and blow on the return to the tank to pressurize and hold it closed with your finger and the pressure will push the gas thru the system. You will see air bubbles coming out the carb return and then when the line is primed it will drip gas with no air.
 
yamanube

yamanube

This Is The Way
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Location
Mandalor
Wave Chaser said:
I might be pointing out the obvious but have you tried priming the line by pulling the return off the carb end and blow on the return to the tank to pressurize and hold it closed with your finger and the pressure will push the gas thru the system. You will see air bubbles coming out the carb return and then when the line is primed it will drip gas with no air.
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Also didn't try that, it was late last night when I got it all in so I didn't try much besides disassembling the carbs and checking fuel line routing. Like I said, it seems to start pulling fuel but once its about halfway to the carb it just bubbles back into the tank, also when I pulled the pump off the carb fuel poured out of it. Maybe a plugged return line is not allowing the fuel to flow through the carb?
 
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yamanube

yamanube

This Is The Way
Staff member
Location
Mandalor
SuperJETT said:
Prime the carb, pull the flame arrestor and put your hand on the carb to block it completely of air, then crank it. The engine will suck fuel through and fill the carb circuits and it'll try to fire. As soon as it tries to fire, pull your hand and get it started.

If that doesn't fix it, then you need to pull everything apart again and double check everything. No crimps in the fuel pump check valves, lines hooked up properly, no blockages anywhere, etc etc.
Click to expand...

Replacing a dirty fuel filter and choking it solved the delivery problem, only to find I had water in my gas. Put in clean fuel and it runs like a champ.

I got the screws to where they seemd to be close but I am having a mid range hesitation. I am thinking the popoff is wrong, there seems to be a quick bog right around mid-throttle, it feels good up to half and feels good after half, a plug chop shows a nice light coffee brown but the mid range transition falls off then picks back up. Any ideas?
 
SuperJETT

SuperJETT

So long and thanks for all the fish
Location
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yamanube said:
Replacing a dirty fuel filter and choking it solved the delivery problem, only to find I had water in my gas. Put in clean fuel and it runs like a champ.

I got the screws to where they seemd to be close but I am having a mid range hesitation. I am thinking the popoff is wrong, there seems to be a quick bog right around mid-throttle, it feels good up to half and feels good after half, a plug chop shows a nice light coffee brown but the mid range transition falls off then picks back up. Any ideas?
Click to expand...

One way I check popoff is to blip the throttle continually. 0%-50%-0%-50% just keep blipping it and see if it keeps pulling. If your popoff is too low, it will start bogging, too high and it'll start starving for fuel and hesitating.

The low jet check is to ride at 25% throttle for 30-60 seconds then nail it. Same symptoms/conditions as above.
 
yamanube

yamanube

This Is The Way
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Location
Mandalor
Mark44 said:
Check this thread out, good info here.

http://www.x-h2o.com/threads/39177&page=3&highlight=tachometer

Mark44
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Good info, thanks Mark. Say I tune it in this way, I get both high and low needles tuned in and still have the midrange hesitation what would be the next step? Lower the popoff?

SuperJETT said:
One way I check popoff is to blip the throttle continually. 0%-50%-0%-50% just keep blipping it and see if it keeps pulling. If your popoff is too low, it will start bogging, too high and it'll start starving for fuel and hesitating.

The low jet check is to ride at 25% throttle for 30-60 seconds then nail it. Same symptoms/conditions as above.
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If I just sit and blip it betwen 0 and 50% it seems okay but if I go from 0-60% or so it hesitates same with if I am blipping it from like 60%-WOT it seems pretty good. If I ride at 25% for a bit then go WOT it seems okay, sometimes it hesitates, sometimes it does not.
One thing I did try was richening up the topend a bit then slowly richening up the bottom end a quarter turn each time. As I turned it out the hesitation problem slightly decreased (never went away) but the throttle response got mushy.
 
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Mark44

Mark44

Katie's Boss
Location
100% one place
Yes set the carbs with the tach is the only way I know of to get them 99.9% correct. Then set your pop off. Do not adjust mixture screws to correct your pop off.

Correct me if I am wrong.
Maybe supertune will chime in here I am not a pro.

Mark44
 
Mark44

Mark44

Katie's Boss
Location
100% one place
i

yamanube said:
After reading the whole thread you said that a tiny tach will not work.....looks like that option is out because all I have is a tiny tach.
Click to expand...

Get a real tachometer and you will have many uses for it, go with a Fluke meter and you can use it to check your electrical system. Quality only hurts once.

Ask yourself this question. How much is a properly tuned motor worth to you?

Mark44
 
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