Noob needs help!!!!

[kdogzx7]

Hi all,
Been lurking and soaking up all the good info here!!!! Having some issues with my 89 GS. I'll start with whats done and maybe someone can tell me what I'm missing.

New intake manifolds
adjust valves
K&N pod
Rejet carb

Now for the issue
Had the pod off last night getting ready to ballance the carbs. Noticed that the left slide was not fluttering and won't move at all till about 7 grand.

I checked the o-ring under the cap, the slide boot, all the vacume lines, still nothing, when I checked for vacume it seems that the carb that isn't moving has more than the one that works right. (Which I guess makes since if the vacume on one is going up and down and the other is staying constant)

Is there a vacume port in the carb somewhere that could be plugged or something else I am missing??

[Affschnozel]

Checked the diaphragms?  Sometimes they rip and pass vacuum , even if it's a little hole that sometimes hard to find.
Take the left one out hold it to a light and check for rips/holes ,that's probably the issue

[baco99]

i know if i rip and pass vacuum, no one is safe!

[scratch]

I'm gonna bet the spigot on the inside of the left carb is not plugged.  That is usually where the vacuum line to the frame-mounted, vacuum-actuated-diaphragm petcock, is attached.

[baco99]

yes to the above.  finding the correct place for the petcock vacuum line is crucial to operation.  mine was place on the right carb byt he PO and i assumed it was correct.  it should actually be on the left.  it's a 3/8" wide nipple on the left carb, closest to the engine.  make sure the hose doesn't have any kinks and you'll be off and running.

[Affschnozel]

i know if i rip and pass vacuum, no one is safe!

 

[kdogzx7]

I actually pulled that line off and plugged it with my finger to see if it made a difference, no dice.  That line just supplies vacuum for the petcock right. So if I capped it off and that's where the leak was it should work?

If it is the diaphram I should just be able to swap them and see if that's it. Right?

I hope I'm better at carb tuning than spelling vacuum!!!!!!!

[baco99]

i tried playing with that too and it doesn't cut it. the line needs to be connected.

[kdogzx7]

Bad times in St. Louis!!!!!!!
Tried everything  I could think of. Did the compression test that I should have done when I bought it.  130psi  on the side thats running well. 40psi on the other
Soooooooooooooooooooooo.... new question. Is it possible I have a valve sticking or something or am I as SCREWED as I think I am??

[kdogzx7]

bumpin

[The Buddha]

40 is plenty low. No idea what may be wrong ... but low it is.
Rebuild time I'd say.
Cool.
Srinath.

[baco99]

my guess is piston rings

[scratch]

Pull the parkplug on that side and squirt some engine oil in the hole.  Rotate the motor over by hand to distribute the oil around the piston and rings.  Replace the sparkplug, and check compression, if it goes up, it's the rings.

[kdogzx7]

Pull the parkplug on that side and squirt some engine oil in the hole.  Rotate the motor over by hand to distribute the oil around the piston and rings.  Replace the sparkplug, and check compression, if it goes up, it's the rings.

Thanks for the tip!!!!!!! I did that today and sure enough it shot up to 130!
Which brings about my next question. Once I pull the head and look at the cylinders  if they are not scored or something wrong with thiem is it just as simple as replaceing the rings? Or do they need to be honed and different rings or piston need to be installed?  Sorry for all the questions but I've never rebuilt an engine

[scratch]

To replace the rings you will need to lift the cylinder block off the crankcase.  If you do not know what a perfect crosshatch looks like, have the cylinders looked at.  You must replace both sets of rings.  Link soon: http://gstwins.com/gsboard/index.php?topic=25011.0

[kdogzx7]

Thanks to those who helped out!!

Quick update and another question.

Finished with the new rings and the bike is back together. Have a set of coils on the way and that should be the last piece of the puzzel.

Now for the question. How long does it take the rings to seat in and will the compression go up as they do. the break in, in the book says 10 hours for break in. Should the compression be in spec. now or will it start low and go up as the rings seat.

[scratch]

Honestly, I don't know, but I'd figure rings should seat within 500 miles, and it makes logical sense for the compression to increase as they break-in.  Here's a link with great info: http://gstwins.com/gsboard/index.php?topic=34329.0