bad rings ?

checked compression on a maxim x #4 had a little,1,2,3 had none. so checked valves #4 had the the tightest valves, exhaust are open, 1,2,3, are not that bad. not sure but rings may be stuck had to use pb blaster to free motor

 

Ok we need to slow it down a bit. first get your valve shims in spec. then test your compression on all 4. then test compression on all 4 after adding a teaspoon of oil to each cylinder. don't forget to disconnect the tci, remove all plugs and hold the throttle wide open when doing compression tests.

 

forgot bike does run it idles and raps out just falls on its face just off the bottom end

 

don't want to pay for the shims to find out no compression

 

Something is wrong with your compression numbers. The bike WILL NOT run without any compression, or even with only one have some compression. You would need to have at least two cylinders high enough to create combustion, and then it would run but sound like a galloping box of metal. You need an absolute minimum of 65psi to have any combustion and that is on a massive tractor piston. Typically these engines won't ignite if the compression is less than 80.

The rings may be stuck, or they may have broken. Get a new gauge, use the 'borrow a tool' service from autoparts store, and retest. This time do a wet test in addition to the dry test. And make sure you are doing the test correct, tester fully threaded in, battery fully charged, throttle fully open, TCI unplugged or plugs grounded, 4-5 cranks or until needle stops rising. Then you will know what you are dealing with. I wouldn't try and run it further until you know.

BTW PB kinda sucks, Liquid Wrench or Kroil is better.

 

I agree with MercuryMan. Need a minimum of 60PSI to get it to run.

 

Check your local chop for a shim exchange. I only said to spec them first because it sounded like you were saying a few might be tight enough where you are risking breaking them. If they are not that bad proceed with the compression test.

 

First time I checked compression, used tape to hold the throttle open. The #'s were crap. Fortunately,realized that the tape had slipped and the throttle was closed.Went back and repeated the process. The #'s were fine.
If it was badly stuck, as you said, when you check valve clearance (the X's are the 20 valve models,aren't they?) you can make sure that the oil passages are open and the top is getting lubricated. Be careful taking the valve cover off and you may be able to reuse the gasket.
You could even squirt Kroil or something in the cylinders before checking the clearance. Might clean up the rings a bit ?
There are a couple forum members who do shim swaps. But don't you have to pull the cams to get at the shims?
Definitely re-do the compression tests.
Sorry,just reread your initial post. So the clearances were mostly okay.
Compression tests.

 

checked compression again turns out the schrader valve was bad in my tester , and i rechecked the valves and got a feeler gauge in all of them but one was .030 mm, really not looking forward to pulling the cams

 

dry and wet testing

Compression Tester Results

DRY TESTING

normal cylinder - needle advances each stroke until hitting max
readings should be within 10 percent of eachother
if needle fails to advance normally, or stays the same for several strokes then starts to climb the cyclinder has a sticky valve
higher readings than manufacturer recommends means carbon build up
if reading is on two cyclinders side by side is 20 lbs or more a defective head gasket may be the prob

WET TESTING

if readings are low or uneven between cylinders pour a teaspoon of SAE30 into each and re-test. IF THE READINGS INCREASE CONSIDERABLY the fault points to poorly seated or worn rings. If the READINGS REMAIN THE SAME the valves are at fault
At least 4 compression strokes should be done to get an accurate reading on the dial

Good Luck

 

What are the specs for the "X" motor? Most of what you'll find splattered all over this site is for the "airheads," which are vastly different.

How did your compression numbers compare to spec for your motor? How consistent across all 4?

 

I curious, has this motor been running or is it a nonrunning project. If the motor was stuck and you had to use PB blaster to free it I suspect it is a new project. It is not uncommon for a newly unstuck motor to have low compression. The rust film in the rings and valve seats will effect compression numbers and valve clearences. I have had many of them before, after some run time on the engine the compression and valve clearences come back into range when the rust wears off.

Just a thought.

 

the bike was sitting for at least 6 years compression # are 100/75/60/85 that was a dry test, the one cylinder must have sticking valves because i could get a .15 mm feeler gauge right after the compression test, than later all i could get in it was a .03mm

 

You could do a leak down compression test and find out where the problem is. This might be more than you want to get into if you don't have a shop. You will need an air compressor and a leak down gauge that any aircraft tool supplier sells for about $75. Get one for 14mm spark plugs, airplanes use 18mm. Follow the instructions and also listen for where any air is leaking. Air coming from the intake is intake valve, exhaust=exaust valve, breather= piston ring blow-by. If your rings are bad for example, you put pressure in the cylinder at TDC of comp stroke at 80psi and if it leaks down below about 60psi, you have problems. Numbers like 80/78 indicate a good test. I have not done this test on a XJ but it should work just like it does on an airplane engine.

 

wet test?

 

Bottom line.

This is a watercooled, 20-valve "X" motor, the same motor they used in the first-gen FJR. Numbers like that won't "self-heal" by running it.

Some bikes that sit for six years are fine; some that sit for 26 are fine.

SOME AREN'T. My bet is that somebody let this one go for too long, maintenance-wise, and cooked it. Not unheard-of.

Beg or borrow a different compression gauge and get a "second opinion."

If you get similar results, either give it up and replace the motor or get ready to drop about $1200.00 into an upper end rebuild.

It's just not worth it. Find another mill if that one's toast.

 

did a wet compression test on the 2 lowest cylinders the one with 75 psi jumped to 175 and the one with 60psi jumped to 125

 

:-(

You have ring issues. Its a bummer but it can be fixed. At least your motor doesn't weigh 400lbs!

 

The bottom line is still the same. I would try with a second gauge; but I'll bet your results will be similar.

If you want to spend some serious $$$ then start shopping for rebuild parts while you tear it down. It would probably be cheaper just to find another viable motor.

 

think i will just part it out, wife liked the bike because it had a sissy bar on the back, thinks she will fall off my CB. thanks guys for all your help

 

" I'll just part it out"
We just love those five words.
Bet the sissy bar sells first.

MN