compression issues

[trippivot]

compression is a main ingredient for internal combustion.

your bike will run on 60 across the board ..yeah it'll be smoking but the ignition is working and the carbs are tuned in.

only 3 basic ingredients #1fuel #2timed ignition -#3 compression

accurately testing the sealing integrity is as simple as this;
cold dry compression test ##'s?
cold wet compression test#'s ?
cold leak down percentage #?

Then warm up the engine, hot enough that you cannot touch the engine surface without pain. it has to be fully up to operating temp then do the tests again.

dry-comp- wet-comp- leak down

Without that information you are only guessing.

[Big T]

No offense intended but get another mechanic or better yet do it yourself.

Agreed

Was the compression test you reference done with the motor hot and the throttle held wide open?

Have you checked the pilot fuel screws to determine of the #4 is broken off?

The compression issue you not in the first post is for bikes that sit for years, typically their oil rings stick together and there's visible oil out the tail pipe

There's a lot more information needed to make a determination and point you in the right direction. It could be as simple as a bad plug cap

But, get your valves properly adjusted first

[rustybronco]

The leak down test was PERFECT and no leak was detected.

Impossible... It has to have some leakage.

http://www.motorcycleproject.com/motorcycle/text/leakdown.html

and my version of the same project... http://thegsresources.com/_forum/sho...eakdown+tester

[barnbiketom]

No offense intended but get another mechanic or better yet do it yourself.

+1 on that

[Nessism]

your bike will run on 60 across the board ..yeah it'll be smoking but the ignition is working and the carbs are tuned in.

You sure about that? I thought 90 psi was bare minimum for the bike to run half way decently.

At any rate, I agree with the need for more info. Engine must be warm and throttle held wide open before performing a compression check. And needless to say, the valves must be adjusted. It amazes me how many people neglect this critical maintenance.

[streetfighters]

So ya pull off the #4 plug lead and experience minor difference in idle. Plugs and wires/coils?
streetfighters

[mike_of_bbg]

Unless the compression test was done hot and WOT, I wouldn't put much stake in the actual #'s.

If the crank is twisted between cylinders 3 and 4 you could show a low compression on 4 from it being out of phase, even if the rings and valves are OK. This should be easy enough to check: set the engine so cylinders 1 and 4 should be directly between TDC and BDC, remove the plugs, and use some sort of slender rod to measure the distance from the spark plug holes to the piston tops. They should be pretty much identical.

At TDC or BDC angular variations will result in little vertical movement. At mid-stroke is where you should see the most vertical difference from a twisted crank.

[suzi]

Just wanted to let everyone who responded to my post that I have printed out all the advise, suggestions and comments that were made and have given to my mechanic.
Hopefully by putting all of our heads(your heads)together we can get this thing back to running how it should.

I very much appreciate all of your input, thoughts, advice and suggestions. If he still can't get it right guess I'll look for another mechanic, or MAYBE try and handle it myself.

Again, many thanks! will keep you posted

[BadBillyB]

These old bikes are known for having vacuum leaks at the carb manifold boots. Usually cracked and leaking "O" rings between the head and manifolds. Spray carb cleaner around #4 while idling and see if you get a response......Billy

[suzi]

Thanks for the tip Billy. I had just replaced all 4 boots and o rings with new set a few months ago. Those things were EXPENSIVE!!!

[Nessism]

Thanks for the tip Billy. I had just replaced all 4 boots and o rings with new set a few months ago. Those things were EXPENSIVE!!!

This place has good OEM parts prices...http://www.boulevardsuzuki.com/