POP off

[ski4]

so in my hell of carb tuning i figured while reading some othe threads to check my popoff.

per pauls rec. i am at stock n/s and spring 1.5 and 115 gm.

checked my popoff a bit ago while changing jets for the millionth time.

anyhow i got a 15 pound difference 140 and 155 many times in a row

i have it a lot closer to 150 and 152. is that acceptable? and how big of an effect will be off by 15 pounds like that be?

 

[sflsurfrider]

HUH????? do you mean compression test or popoff test???

those numbers are WAY high for popoff.

 

[ski4]

pop off
according to mikuni that combo should yield around 53 or 55 pounds i think
on stock 38's

 

[sflsurfrider]

re-read your first post

 

[ski4]

oops must have inhaled too many fumes out there, i meant 40 and 55 psi
:banghead:

 

[sflsurfrider]

150-152 is acceptable

140-155 isnt

 

[ski4]

good, really don't much feel like going back out tonight.

being off like that, is that something that will mostly just effect idle smoothness

 

[sflsurfrider]

i wouldnt think thatd effect the smoothness of your idle, since at those RPMs, you n&s's should be closed full time.

 

[ski4]

doesn't fuel flow through the needle valve before getting to the low speed jet and low speed adjuster?

 

[sflsurfrider]

er, yes it does. too low a popoff can cause a dribbler an therefore make your boat idle all funked up.

i wouldnt think 40 lbs psi is too low to do that though.

 

[ski4]

that's cool, i didn't think it would be a dribbler either
if anything this prolly just made it tougher to dial in the low speed circuits i am guessing

 

[550 SLUT]

i have the mikuni arb tuning book

just as me and i cn email it to u

 

[Matt_E]

http://www.mikuni.com/pdf/sbn_manual.pdf

:biggthumpup:

 

[ski4]

thanks guys i have that, it just never said what is an acceptable deviation in the popoff between the two.

seems a bit better today. still got some minor tweaking to do, starting to think some of it is my pipe now though

i have not really played much with that yet, at least not with the ski running decent.

maybe this weekend

getting tired of pulling off those carbs anyhow

 

[djkorn1]

your a carb tuning FREAK!!!!

 

[ski4]

i fing hate it, i would rather chew tinfoil
it's a fun ride now at least still seems to be missing something though, it may be the pipe, and since it's a freestyle prop( or so he says) maybe some of the reason it's not as fast on top as i though and maybe something to do with the rev limiter??????