[GSX750ES '83 lower compression in one of cylinders]

Update:

First I draw off  engine oil, then I removed all spark plugs and  put some amount of kerosene in each cylinder. After several hours cylinders were empty so I put kerosene again. Did this procedure 4 times total in the past two days. Today I put the old oil inside the engine again to wash the motor inside. Then started the engine to warm up and after 10-15min removed the plugs again to check compression.

All cylinders are around 132-136psi and it seems  kerosene did help! Did a test twice  the just to be sure and everything was fine, so now i'm happy again 

Now I only have to put  fresh oil and I'll be ready for action 

[GSX750ES '83 lower compression in one of cylinders]

Hi arnout,

I do not complain about poor engine running at all. Just did the compression test as a routine task as i have the gauge.

BTW last time when i checked the valves, about 2 years ago i did the compression test again and all cylinders were fine then. Anyway i also suppose there is stuck rings in this cylinder as you said, so tomorrow gonna put some kerosene to see if it helps remove carbon deposits if any.

 

[GSX750ES '83 lower compression in one of cylinders]

Hi all!

Owner of  "oldschoolsuzuki" GSX750ES 1983, but new to the forum

Today I did a routine valves check and tolerances was just fine on all cylinders. Then i decide to check engine compression to see how is it. 

I did it wiht hot engine, all plugs removed and with throttle fully open and these are the readings that i got:

1st - 132psi

2nd - 136psi

3rd - 128psi

4th - 90psi only!!!

 

Then I put small amount of oil inside 4th cylinder and did a test again. The result was 142psi so the problem most probably is in the piston rings for me?

According to manual engine has to be overhauled if there is such a difference between cylinder's compression.

It's not my main bike so I ride her from time to time for short trips as I have another motorcycle to travel.

Can't say  that i feel some lack of power, i'm not sure as i really can't compare it with my other bike with 150hp   

Oil consumption is reasonable i think around 200ml/1000km

Do you think it's such a big problem for 35 years old bike and what would you recommend me to do?

Thanks in advance for your answers!