Thread: Popoff pressure at 46 PSI ?!?
09-19-2011, 05:29 AM #1
Popoff pressure at 46 PSI ?!?
Just rebuilding my Mikuni BN44, and upon doing hte popoff pressure test find that is pops at 48PSI using the bright silver spring in the genuine mikuni rebuild kit, so I tried the old spring and that goes at 46PSI.
However the tables I have seen show that for the 1.5 needle it should pop at 32. I can understand it being a few out, but not this much.
What can make such a big difference, or is there anyway that it should be 46-48PSI?
Its a 1995 701 engine (62G) , single carb.
The ski wasn't running when I got it so I didn't measure it before I pulled the carb apart. Have checked it using 2 different gauges.
09-19-2011, 09:58 PM #2
That is quite a bit off. Are you using WD-40 to lube the needle and seat like the Mikuni service manual recommends? They did change the "Gold" 115gram spring to "Platinum" and its hard to tell the difference between that and the silver spring. I believe the 115g spring comes with the rebuild kit and thats probably what you installed. Just for reference, when I did my 3 carbs, I used the 115gram spring and 1.5 NS and came up with 48psi pop off pressures
09-20-2011, 08:53 AM #3
10-06-2011, 09:17 AM #4
- Join Date
- Feb 2011
So if 48 PSI is too high, where should it be on a 701?
10-09-2011, 06:47 AM #5
6R7-14253-00-00 which is apparently the 115g spring, which used to be gold colour coded and is now platinum, and seems to be the one included in the Mikuni rebuild kit (either that or it is the silver one thats included, but the silver is the softest one so doubt its that one).
So guess it maybe the right one all along?!
10-12-2011, 08:22 PM #6
Stock should be 1.5 N/S and 115 spring.....if it's 100% stock go that route. The color on the 115's did change...be careful one spring looks right but is only like a 60-65 gram spring ...not the 115
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