[TPaasch]

I today decided that winter is over, and took the bike for its first spin since end October. The weather wasn't all that great, but around 10°C and almost dry.
After sitting for 4 and a half month, the bike started at the first attempt with a little choke - oh joy.

I took it for a 60km ride, and all works like it should.
I just recently bought my self a compression tester, so I though it would be a good idea to check compression now the engine was nice warm.
I took out both spark plugs and test first the horizontal and then the vertical. The good news is that both reading are identical, but only 65 psi. That's pretty low isn't it?
The funny thing is that it starts well, idels well and pulls well (I only have had it for a year, so I don't know if it should be any different from what it is).

It a 1999 moster 600 and has run 29.000 km. I have no maintenance history of the bike, so I assume valve adjustment would be the obvious next step - or any other suggestions?

Regards Thomas

 

[auwozza]

If your using the screw in adapter some of the cheaper kits leak badly...use the attachment that has the rubber wedge on it and push in hard as you crank, also make sure throttle is fully open. If still low try a teaspoon of oil in each pot and re test if it comes up most likely rings if not valves maybe the issue

 

[TPaasch]

If your using the screw in adapter some of the cheaper kits leak badly...use the attachment that has the rubber wedge on it and push in hard as you crank, also make sure throttle is fully open. If still low try a teaspoon of oil in each pot and re test if it comes up most likely rings if not valves maybe the issue

Thanks auwozza. I missed the "throttle fully open" part. I didn't though the throttle at all. I'll give it another try after next drive. Right now the raining ☹

 

[TPaasch]

auwozza
You where right in both your suggestions.
Opening the throttle got it to 85. Using the attachment with the rubber wedge got it to 120, even though it wasn't easy pressing it in, giving full throttle and push the button at the same time

Thanks for the advise, now things don't look that bad anymore...