[heathmcabee]

Should I be worried here? Cylinder 4 is at 154 while rest are in the 175+. This is on a 2007 750 with 9k miles i dropped in ny 600. Help?

 

[Beairsto Racing]

As a general rule, you should see no more than 10 percent variation between the highest and lowest readings.
So if this is a street bike, you're still more or less, within an acceptable range. and should be able to sleep at night.
Keep records and compare again, the next time you're under the tank.

Did you crank the engine over an equal # of times, for each cylinder?
Was the engine warm?
Are the valve clearances within spec?


If it's still apart, and you want to play some more...while testing #4, if you were to crank several more times than you had with the other cylinders, and you noticed the pressure pumped up another @10psi, it would be an indication that the rings are worn in that hole.

-Scott

 

[Just_Nick]

That is definitely lower than you want it to be.

 

[heathmcabee]

Didnt raise anymore when I gave it more juice. One thing I do remember is it was the last one for me to check and maybe the bike was getting cold? I had used a crappy Harbor Freight test kit and they were all at 90 cause of its crappy design but borrowed one from Advsnced and wqs results I posted.

Havent dug into the engine yet and can hear a noticeably slight but could say more distincitve gixxer tick on the side with #4.

Vavle clearances can give me back that %?

 

[oldgixxer]

Vavle clearances can give me back that %?

You won't know that unless you do a leak-down test

 

[heathmcabee]

Okay pics uploaded for you to see results. So leakdown then valves.? Add oil to cylinder and see if it goes up? holding down starter longer didnt help.

 

[Beairsto Racing]

If you don't know the maintenance history of your "new" engine, I'd check valve clearances regardless.

 

[heathmcabee]

all my exhaust valves where off big time. check this out

Had to cut image in half for upload. This is exhaust side. I got 80HP on the dyno cause of these clearances. Hope this fixes it.