oil breather, loosing oil

Hi

I've never done the test, but it looks to me that the autodecomp will never let you have max compression, at least in one of the cycles, but at this hour of the morning my brain still doesn't work :|

:cheers:
ZAGA

to overcome the autodecomp, back off the left exhaust valve setting to perhaps a full turn or more.

I did a service today and decided to check my compression, using electric start and throttle wide open i wasnt able to get an accurate reading, the longer i let it crank (up to 15 engine revolutions?) the higher the guage would get, i got a reading up to 230psi, it definatly cranks faster with the throttle open, with throttle open and a 2-3 second button push psi would be in the 140-160 pressure ranges, if i left the throttle closed and let it crank 10-12 engine revolutions it would max out at exactly 140 psi every time.
i did not try the test with the kick start at all, maybe if using the kick start having the throttle open would be easier because the engine cranks easier? i am not sure why this is required, i got more consitant and im sure accurate results with the throttle closed, i also did not change the valve settings at all while testing, this i am guessing why it takes so many revolutions to max the guage? my bike kick starts ok cold and easy when hot and starts easy with electric start hot or cold, maybe i have something out of adjustment slightly?
When i say revolution i am sure its not a complete revolution but probably 1/2 revolution, each time the engine makes a "ereow ereow ereow" noise i was counting as one revolution...i am not good and making sounds effects and even worse at spelling them, i think you know what i mean...
i am sure i will be enlightened as to why one should check compression with the throttle open shortly....its the middle of the day and my brain still hurts...maybe i am thinking too much :? ...

Throttle open. In order to get compression, you need something to compress. The more air available to the cylinder, the more accurate the reading. It is normal on all engines for the compression to climb on additional revolutions. eventually the reading will max out. You want to stick to 3 or 4 revolutions for your test.

The fact that the compression ring is doing it's job does not mean the oil control ring has not failed. In fact if the oil control ring is failed it can allow enough oil onto the cylinder wall to raise the compression readings up to cover a bad or weak compression ring.

And just when you thought you had it all figured out.....

I know the feeling :cuss: My 600 put me in crutches

Buy the newer kick its is much much better

:cheers:
ZAGA

berger, before i continue i firstly want to say i am not trying to be a smart alec, nor and i saying im right and your wrong by any means, i just do not understand and would like to, all of my knowledge is based on automotive repair, in a car engine compression test one would attached guage throttle closed 3-4 revolutions and the guage is maxed at your reading, exactly like when my husaberg engine turns 10-12 times it maxes the guage at the pressure i would expect to see repeatedly.
with the throttle open i understand there is more air available, the engine cranks easier and gets the reading into the expected range in 3-4 pumps, the difference is that the readings i got were all over the place with the throttle open, if you got to 5-6 pumps now the guage reads 180 psi, if it only got to 2-3 pumps it may only be 120psi, if i would have done the test ten times then took the average i probably would have been at 140psi, it just sees like you are guessing if its done like this, with throttle closed if i did three tests consecutivly it would be 140psi, 140psi, 140psi, thats easier to get an average from...

berger said:

The fact that the compression ring is doing it's job does not mean the oil control ring has not failed. In fact if the oil control ring is failed it can allow enough oil onto the cylinder wall to raise the compression readings up to cover a bad or weak compression ring.

Click to expand...

that i did not think of, so basically doing a compression test still does not rule out a ring failure unless
the reading was way low and something was obviously broke...

berger said:

And just when you thought you had it all figured out.....

Click to expand...

I wish.....at least i have baseline on my bike i can compare to later if needed, reguardless if my test is right or wrong, in the future if i do the same test then see different results i can expect something is going on....

always throttle open. if you were getting varied readings on a husaberg, it was prolly the auto decomp.

Ok i think that makes more sense..... i will have to accept that answer untill my next valve adjustment when i can do more testing and be sure that the auto decomp is disabled to not fudge my results, if i was not an auto tech i would probably not be set in my ways on something like a simple compression test procedure and would just take your words as gold, however, my curiosity gets the best of me frequently and unless i can see the results my thick skull prevents my brain from accepting things than are not normal to me sometimes....thanks ned and berger for trying to make sense of that to me, as for Mr. Noodles sorry to hear about you unfortunate luck with the kick start lever and the oil consumption...best of luck finding and repairing the problem :cheers: