Pop off adjustment

[Jgreelz]

I had a similar problem a couple years back. The return port was plugged up not letting the excess fuel return to the tank. I cleaned out the tiny port in the carb and it ran perfect after that.

Ok I thought I spayed it out pretty good with carb cleaner but I'll double check since I'm pulling them out again soon. Note it did run today, a after turning the gas off all night. Just ran a little rough and dies at idle. Hopefully with new mikuni needles and diaphragms and maybe low speed idle adjustment I'll be good. Going to be a few days before I can get to it but I appreciate everyone's feedback keep it coming

 

[mikidymac]

Follow the carb sticky. If the kits were less that $50 they aren’t genuine. If the needles and seats were less than $16 they aren’t genuine.

 

[Jgreelz]

Follow the carb sticky. If the kits were less that $50 they aren’t genuine. If the needles and seats were less than $16 they aren’t genuine.

Ya I figured that out lol. Just ordered genuine mikuni parts.

 

[Mraw]

If you had aftermarket diaphragms then I would definitely switch them out for genuine mikuni

 

[Jgreelz]

Ok I need help. Put new needles and seats in and trying to do a pop-off test. I filled the needle seat area with gas I hook up the pop-off tester to the inlet hold my thumb over the outlet and I cannot get any pressure on either carb. I tested pop off tester just by putting my finger over the end of it and it builds pressure fine. What am I doing wrong.

 

[Jgreelz]

It just sounds like the pressure comes out from inside the car somewhere

 

[Jgreelz]

Okay new development I found that the second carb the one without the pump was leaking on the other side from the seal. I put the old seal back in and I can do a pop off pressure test and it pops off at 29 The only thing is I'm not having to put my finger over the outlet It builds pressure without me holding my thumb on the outlet is that a problem?

 

[Jgreelz]

So I hooked up a hose to the fuel return line blew into it and it holds pressure but when I suck it also holds pressure It seems the fuel return is clogged internally somewhere How do I clean it out

 

[Jgreelz]

Okay guys took me awhile to get to these carbs but I need some help. I put new Mikuni needles in doing a pop-off test and one of my carbs is popping off at really high pressure well above 30. My gauge only goes to 30 but I'm guessing it's around 40 at least. How do I adjust it to get it down to 29 or so?

 

[Jgreelz]

Just rebuilt carbs on my 1994 GTX and pressure is popping off well above 29 psi. My Guage only goes to 39 psi but it's way past that, like 50 psi. How do I adjust the pop off to be lower. Do I need new springs or can I bend the lever to adjust it?

 

[Jawilson7820]

The kit should have come with different springs.

 

[Jgreelz]

Ya so I got a crappy aftermarket kit and it was garbage, the seals it came with leaked so I couldn't even get any pressure on pop off test. I put old original seals back in and it held pressure and popped off, just too high. I ordered new genuine mikuni diaphragms and needles/seats but not the springs. So I'm afraid to use those aftermarket springs and from what I've read you should stick with the OEM springs.

 

[GGuillot]

The only thing is I'm not having to put my finger over the outlet It builds pressure without me holding my thumb on the outlet is that a problem?

Test it with the return plugged, I haven't tried it unplugged so I can't say what it should do. Spray penetrant like PB blaster or WD 40 on top the needle/seat. With the tester connected to the inlet slowly apply air pressure and observe the "pop" psi of the needle lifting off the seat. Do it several times to get a consistent readings. Do the same for the other carb, should be about within 1 psi between the two. Ck specification for pop off psi for your carbs, I'm not sure where 29 psi would fall for your carbs, the ones I've done are 787 engines.

Sounds like you on the right track though...

 

[Jgreelz]

PSI for my carbs is 22 to 29 psi. One pops off at I'm not 100% sure but around because my pop off tester only goes to 30 psi but it goes way above that 50 PSI the other one is about 35. I pop them off three or four times each. One problem I'm having is the second carb The fuel return seems to be plugged I can pop it off without even plugging the return. So to test that return I blew into it and it held pressure like it should but I also sucked through a fuel tube and it also is pressurized It will not give me any air or fuel when I suck on it so something's wrong It's got to be plugged up.

 

[GGuillot]

How do I adjust the pop off to be lower.

The spring adjusts the pop off, not bending the arm. According to pop off spec for your ski it's between 22-29 with 2.0 seats. Try different springs and see what you get. Someone on here should be able to advise which gram spring it takes.

 

[Jgreelz]

The spring adjusts the pop off, not bending the arm. According to pop off spec for your ski it's between 22-29 with 2.0 seats. Try different springs and see what you get. Someone on here should be able to advise which gram spring it takes.

Ok yeah from what I've read the OEM springs and levers shouldn't be messed with but it sounds like maybe I need to try these aftermarket springs and see how they work I'll do that if I can find them lol.

 

[Jgreelz]

Ok yeah from what I've read the OEM springs and levers shouldn't be messed with but it sounds like maybe I need to try these aftermarket springs and see how they work I'll do that if I can find them lol.

Also yes I got 2.0 needles and seats.

 

[GGuillot]

PSI for my carbs is 22 to 29 psi. One pops off at I'm not 100% sure but around because my pop off tester only goes to 30 psi but it goes way above that 50 PSI the other one is about 35. I pop them off three or four times each. One problem I'm having is the second carb The fuel return seems to be plugged I can pop it off without even plugging the return. So to test that return I blew into it and it held pressure like it should but I also sucked through a fuel tube and it also is pressurized It will not give me any air or fuel when I suck on it so something's wrong It's got to be plugged up.

See your other thread, but I'll add, you probably should have a gauge that goes to at least 60 psi. You need to figure out which spring your actually working with and the one you actually need.

 

[GGuillot]

Ok yeah from what I've read the OEM springs and levers shouldn't be messed with but it sounds like maybe I need to try these aftermarket springs and see how they work I'll do that if I can find them lol.

I ended up ordering new springs, I couldn't verify what the hell I was working with. With the right stock spring and new arms along with the new needle/seats it should be factory stock setup and within pop off range. Then it's a matter of adjusting the carb needles (low and high) to the stock settings.

 

[GGuillot]

Okay guys took me awhile to get to these carbs but I need some help. I put new Mikuni needles in doing a pop-off test and one of my carbs is popping off at really high pressure well above 30. My gauge only goes to 30 but I'm guessing it's around 40 at least. How do I adjust it to get it down to 29 or so?

Geez, you now have 3 threads all asking the same thing...

 

[Jgreelz]

See your other thread, but I'll add, you probably should have a gauge that goes to at least 60 psi. You need to figure out which spring your actually working with and the one you actually need.
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The springs are oem as far as I know. They are thicker and darker colored than the aftermarket ones.

 

[Jgreelz]

Geez, you now have 3 threads all asking the same thing...

Yea needed a response

 

[Jgreelz]

Well the aftermarket springs popped of at 15 psi so I went with the old ones, even though one of them is popping off too high. Got it back in the ski and seems to be running pretty good, thanks for the responses.

 

[mikidymac]

Never use any aftermarket carb parts in these.

 

[Jgreelz]

Never use any aftermarket carb parts in these.

Yup, I figured that out the hard way.