130psi compression (is this bad?)

[2002zxi]

I dont know what aftermarket head is on this ski, but here's a pic:

This ski has around 130-135 on each cylinder and has a Freeride port job by Group K.

Is everything okay or do I need rings? This ski has a ridiculous amount of power still.

 

[Whale]

yer thats what mine is at aswell i thort it'd be way more than that i got ada head bpipe no porting tho
when i checked mine i didn't have it at wide open throttle tho ill check tomoro

 

[gj_fx1]

I think if you have "around" a 5 psi range you need a better gage..

 

[2002zxi]

I think if you have "around" a 5 psi range you need a better gage..

awe come on now... have you ever tried to hold a compression gauge and a rattling SJ at the same time?

Also, I guess you never took any science courses. You cant measure numbers you're not capable of measuring with your instrumentation.:biggrin:

 

[Mouthfulloflake]

well, maybe we should have written the numbers down?

oh wait, here is my note pad lets see.

134.784 psi on the front hole
133.476 in the pto cylinder.

NOW, know that those are the EXACT irrifutable numbers.

why are they so low with the aftermarket head?

does the group K porting reduce the cranking compression this much?

or is this the wrong head application?

-- Dustin.

DONT touch that ski.
there is NOTHING wrong with it.
trust me.

 

[gj_fx1]

Get a screw-in. I wasn't trying to be insulting, but you do always have to wonder about the gage and how the test was done when someone posts numbers that seem low. Two stroke especially the numbers are sensative to cranking speed, throttle open, how many revs you gave it etc.

 

[Mouthfulloflake]

Get a screw-in. I wasn't trying to be insulting, but you do always have to wonder about the gage and how the test was done when someone posts numbers that seem low. Two stroke especially the numbers are sensative to cranking speed, throttle open, how many revs you gave it etc.

it was a screw in guage, a new one at that.

do you have any input on WHY the numbers are so low?

other than questioning our technique?

the cranking speed was fine, WOT throttle, makes little to no difference in my experience with 2 strokes.

 

[2002zxi]

Get a screw-in. I wasn't trying to be insulting, but you do always have to wonder about the gage and how the test was done when someone posts numbers that seem low. Two stroke especially the numbers are sensative to cranking speed, throttle open, how many revs you gave it etc.

lol, I was just messing with you. It was a screw in gauge attached to the end of a 1 ft rubber hose. It was mouthfulloflake's so I dunno much more about it.

 

[Mark44]

I checked my comp with two different gauges my new gauge was -15 pounds different than SXR Lou's gauge. You should check with another gauge.

You also need to check your squish angle to see where it’s at that is very important it may be too high and that’s why your comp is so low with that head.

Mark44

 

[Mouthfulloflake]

I checked my comp with two different gauges my new gauge was -15 pounds different than SXR Lou's gauge. You should check with another gauge.

You also need to check your squish angle to see where it’s at that is very important it may be too high and that’s why your comp is so low with that head.

Mark44

that guage is close enough, it showed 150 on his other ski.

did we check my skis with it Dustin?

because ive checked mine with another guage and could compare that way.

I think its reading right. ( close enough)

 

[2002zxi]

did we check my skis with it Dustin?

YEah, we checked the black one. The front cylinder had 80 and the rear cylinder had 95.

 

[Mouthfulloflake]

80 and 95? I dont remember it being that low.

it really?

in that case, yeah that guage is LOW.

well, unless that boat has lost some ring seal in the last week or 2, it was 150 on my guage a few weekends ago.

I didnt remember it being that low.

hmmmm

 

[Mark44]

Maybe the squish is about .125......................

Mark44

 

[Mouthfulloflake]

Maybe the squish is about .125......................

Mark44

if it showed that low on my black boat, its either a 40 psi under guage, or mine has detoriated since LOTO

 

[Mark44]

l

if it showed that low on my black boat, its either a 40 psi under guage, or mine has detoriated since LOTO

I was just joking I had thought 2002ZXI was also joking about the comp.:biggrin:

Mark44

 

[keefer]

What cc domes are in that head. 135psi seems way too low. I think that you should be running around 180psi with 35cc domes. See if you can find someone who has a Snap On guage. They seem to read accurate, I have used several types and most have read low except for the Snap On.

 

[Mouthfulloflake]

maybe he was joking!

I was drinking severly the day we checked them...

so it could have been 230 in hole, and 8 psi in the other.

:dunno:

 

[Mark44]

g

maybe he was joking!

I was drinking severly the day we checked them...

so it could have been 230 in hole, and 8 psi in the other.

:dunno:

:haha: :haha: :haha: :haha: :haha: :haha: :haha:

Mark44

PS:

"Ketsair eats worms also"

 

[Mouthfulloflake]

worms?

uhhhhhh?

tequilla worms?

or canadian night crawlers?

he likes pork butt tacos too, but he is scared of tobasco suace.

:haha: :haha: :haha: :haha: :haha: :haha: :haha:

Mark44

PS:

"Ketsair eats worms also"

 

[Mouthfulloflake]

saki,

its obvious you need a lower quality guage.

or a more sober guage.

:Banane01: