ZL 1000/900/600/250 Compression Testing

R. J.

R. J.

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:hello: I couldn't find a thread on doing a compression test on the ZLs so I decided to do one. Here is instructions/procedure on how to go about performing a compression test. This applies to any gasoline combustible motor. IMG_4423.JPG
 
IMG_4435.JPG :hello: Here are pics of tools that may or may not be needed but any good tool is a great tool that makes a job easier. I number the spark plugs using a black sharpie. IMG_4434.JPG IMG_4424.JPG IMG_4429.JPG IMG_4431.JPG It is best to use a 18 mm 6 point deep well spark plug socket. You can always cut a piece of rubber hose & insert it into a regular 18 mm deep well socket.
 
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:hello: While I just got done doing a Compression Test on Ron D. ZL 10. See pics for results. Cyn 1 threw 4 was done in order as the pics was taken. I wonder if I'm going to be blamed for this to. :laughing7:. It was fine 2 weeks ago. IMG_4438.JPG IMG_4439.JPG IMG_4440.JPG IMG_4441.JPG IMG_4442.JPG IMG_4444.JPG IMG_4443.JPG
 
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Maybe time to adjust the valves on that one.
 
:hello: It is way past the time for the valves to be adjusted like 4 years ago. The bike was getting really bad gas mileage from the first day Ron owned it. I told him at least 10 times that he shouldn't ride it until the valves get adjusted. It has over 24 K miles & most likely the valves have never been done & the carbs was never done. Cylinders two & three are so low on compression that the motor may need a valve job. I know when I call him he is going to blame it on me. It was fine 2 weeks ago. I must of heard that a dozen times. At this point I don't even care if I get paid for all the other work that I have done. I'm not bad mouthing him either just pointing out the facts.
 
:hello: I learned a lot on this bike. You always do when you're pulling out your hair. I sort of wish it didn't happen like it did or I would of thought of checking the compression earlier. The bike acted like the problem was an electrical issue but when each time I'd start it after changing a part or what ever the problem of staying running would get shorter. I never ran it for all that long maybe a minute or two. I never test rode it for fear of messing something up. So the last time it was started it ran for only 20 seconds or so. Then it would not start at all but I did not lay on the starter button much. Again I did not want to screw something up. I said to myself self it fired right up when I put the carbs on the last time & idled smooth as silk. So I called my friend Ron A. & explained to him what was going on. He said the valves are really tight & that I should do a compression test. I did tell him that the bike was only getting around 20 MPG since Ron D. first bought it almost 4 years ago. Tomorrow I'm taking the bike to our friend Jeff. I just don't have any more time to spend on this bike. Iv'e had it for 7 weeks. Half of that time was waiting on parts & half of that was trouble-shooting.
 
Could you have some bent rods from hydrolock that is resulting in low readings? I like to do the dowl rod measuring when I'm working on a motor that I know no history of.
 
:hello: I thought of that but the bike was running good above 3 K RPM when I started on this bike so no I did not do the dowel rod test. What I use for that is I ripped down 12 inch medal ruler so that it will go down into the spark plug hole. The bike is gone now anyway. Jeff & Ron D. Uncle Steve picked up the bike an hour or so ago. I went over everything that I done to it with them. Jeff said with only 24 K miles he sees no reason to adjust the valves. It's no longer my problem.
 
:hello:I did mention the 5 K valve check per the GPZ Service Manual. Jeff is an all round stand up guy & a very good Mechanic :notworthy: but for some reason stays away from adjusting valves. :banghead:. He asked me how I went about doing the compression testing my response was that I followed the Procedure that came with my Set-up. I got my compression tester & he declined doing another Compression Test. He said he was going to start over from ground 0.0 & first pull the carbs for cleaning. We did start the bike while he was here but never revved it past 2 K. & for some reason the bike stayed running for about 15 minutes. He pulled each plug wire one at a time while the bike was running. # 4 cyn was dropping out intermittently. So we drained the fuel from # 4 carb. The fuel level seemed fine. So he said most likely the pilot jet is plugged. At this point I didn't say anything. I do not want any bad blood between us. I like Jeff & have the utmost respect for him. We did manage to here the fan come on both times as it should. The fan Circuitry System is the main reason for me taking the bike. Jeff said he will do a Compression Test after he does everything else. On a side note the bike was fine 2 weeks ago. :laughing7::laughing7::laughing7:. That was true but after what Jeff & I do to it will be the 6 million $$$ ELIMINATOR!!! It will be faster & stronger than ever. :notworthy:. Ron should have a trouble free bike for quit sometime. :notworthy:.
 
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Ground 0.0....adjust the valves...lol
Fuel flow into cylinders doesn't change compression readings. Oh well, hope he gets it sorted out, may end up being another cheap bike on CL next summer.

I just missed a clean 05 zuk gs500f in great shape for $550 cause dude ran it for 10k miles and the carbs clogged up on him. He just wanted it gone. Too slow otherwise I could have done a quick flip.
 
Up here in New England we have four seasons; early winter, mid winter, late winter and next winter.
 
2 seasons in the burgh, winter and orange barrel season fixing the damage from the plows.
 
:hello: While I talked with Jeff & he did a compression test on Ron D. ZL 1000. All 4 cyn came back with 80 to 110 PSI. He did the test with the carbs off the bike. He said that way the cyns get more air. I'm not really sure if that matters. He said that he will not adjust the valves. :banghead:. I thought that a bike should have 125 PSI or greater.
 
:hello: I think time's up to adjust the valves on that bike, next repairs will be 'more heavy'...:laughing7:
 
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