Advice on this Kz550

I managed to use a bit of motor oil in engine for cyc 2. Reading jumped from 60 to 105....Thoughts

Those are very low for a 550 motor. Even an old worn out engine reads in the 170 to 180 psi range. With the motor cold, that might lower it a bit, like 10 psi, but not as low as you have.

Did you have the carbs off when doing the compression test? That's ok. But if the carbs were on, you have to have the throttles wide open and no choke.

Another issue is some compression gauges don't have a check valve right at the tip of the insertion probe. If yours has the check valve further up the hose or at the gauge body, that would account for the low readings.

As for cyl #2, that is a problem because it's so much lower than the others.
Have you checked the valve clearances? If they are all in spec (particularly #2), then I think you may want to do a leakdown test to determine which valve is leaking or if there is a ring problem.

www.amazon.com/gp/aw/d/B000EVU89I/ref=yo...e-view_1483985972628

I know it has the pressure release on the side of the gauge.This was done with the carbs off, my battery isn't a new one but the one the po had. I haven't kept it on the battery tender I have so I charged it up for about a day Saturday/Sunday. The electrolyte level was approaching the min line. Should have brought my meter to the garsge so i could see how it was functioning under load. So my battery isn't brand new, still doubt that would be the cause of of the the low compression for cycl 2.

Yeah checked the clearances a few times earlier. I'll try and get a leakdown tester as soon as I can.

That tester appears to have the check valve at the end of the hose, rather than at the tip of each adapter. This means the volume of the adapter adds to the volume of the combustion chamber. This lowers the static compression ratio and might explain the overall lower readings.

That's ok, as long as you know why the numbers are so low (but #2 is a different story, obviously).

Performed a leakdown test.all the cylinders show a slight drop from the incoming pressure. All four cylinders have a leak that can be heard from the oil crank case. It can be heard significantly for cylinder 2 along with a gritty sound as if specks of dirt are bouncing around.

The percentage of leak is slightly larger on cylinder 2.

Are you able to perform the leakdown test with the engine at normal operating temperature? Doing that might change the readings since the pistons will be expanded and that might improve the piston ring / cylinder wall seal. Ed

Possibly, the carbs are 95% assembled the only thing that have not do to them is do the clear tube test for the float heights. But im sure I can get them together and perform the leakdown test again if necessary.

Morning everyone, I have not been active on the site much but I have been doing some work on the bike aside all of life and all its hiccups.

I've adjusted the float heights to spec will be performing the clear tube test later this week once I build a stand. BTW awesome in depth write up on floats and differences in aftermarket needle valves Lou. Previous owner had pods on there but to compensate I believe they messed with the floats as they were bottoming out. I will be doing a oil/filter change later on this week and post my results.

The one thing that has been a dead end is the dam airbox. I boight one over a year ago for a test fit. Of course it was a airbox that was used for a earlier 550 model so the two inner airbox orifices were slightly smaller. Coupled with the fact that the 2 inner air ducts are obsolete that was a no go.

So I decided I'd go an alternative route. Use fernco rubber couplings for duct substitutes.
Rolled the dice on a 550 M model airbox recently. The orifices were roughly the same and I crosschecked and saw that the m model also used tk26 carbs. It mounts roughly the same although the breather tube to the crankcase does not align so some modification might be necessary. My only concern is the m model airbox will affect the af mixture.

I hope my line of logic in terms of doing all this is fine. Just want to warm the bike up with those components on there and redo the compression test.

It is amazing how limited info I is for this one year model in terms of airbox.

The first is the m model airbox the second is earlier year a model

It sure would have been nice if the previous owner could have kept the airbox and gave it to you.

Even with the airbox, I run a hose from the breather. There will be a lot less nasty grime in the airbox this way.
www.kzrider.com/forum/2-engine/502609-cr...l=component&type=raw

Alright will note that. So unfortanely i have to scrap the idea of the M airbox, literally no clearnace with it. The other airbox might be the only option, just to verify a few things I got a few questions.

1. Once the L brackets are installed in the airbox and attached to the frame (battery case) should that provide adequate space to manuever the carbs into the intake manifolds?

2. What is the correct orientation for the boots? Did not see any indicators or markings on them? Is it similar to how I have them set up in my picture?

If you look at the boots, you will see small notches on one of the lips near the airbox. There should have been a small tab that lines up with that notch. I think your boots are supposed to go into the airbox so that the notched lip is flush with the airbox wall. Then the notch will engage the tab. If the airbox and boots are a mismatch, the notch/tab alignment might not be valid.

If I remember, I'll check and see if the notch is straight up on my 550's (but they are all TK22's, not TK26's).

To install the carbs, the boots have to be in the airbox, and the manifolds have to all be installed. But you keep all of the airbox hardware loose, including the battery box etc, so it can all move backward slightly.

Then I sit on the bike, on the center stand, with the tank removed, and put my feet on the alternator and ignition castings. I then move the carbs in below the boots and engage the intake of the carbs with the boots of the airbox, then pull the carbs into the airbox as hard as possible until I can just get the "nose-in" the carb outlets into the manifolds. I put a tiny smear of antiseize on the carb outlets so they will be easier to remove next time.