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This motor uses a lot of oil, and started all at once.

I flushed out the oil breather.
2 different compression reading two diffent times.
110 and 210.
This morning, 165 and 180. Which seems high for a small motor.
I don't have a cylinder leak down tester yet.
What could it be? Thanks

ba_50 said:

This motor uses a lot of oil, and started all at once.

I flushed out the oil breather.
2 different compression reading two diffent times.
110 and 210.
This morning, 165 and 180. Which seems high for a small motor.
I don't have a cylinder leak down tester yet.
What could it be? Thanks

Click to expand...

It is actually a cv624s

Using oil, oil sump over filled. Head gasket or rings.

Run the valves and check compression. 180 and 210 is very high. Valves might be too loose. Maybe a partial missing cam lobe super wear issue? 210psi is around 14.7:1 compression. As in drag racing motor compression.

Been mowing on the ski slopes any?

Blown head gasket on one side ( the low one ).
Run the engine for 10 minutes then shut the engine down & pull the dip stick out.
IF you get wafts of grey smoke then either a head gasket has gone or rings have gone
In either ase the head has to come off .

slomo said:

Using oil, oil sump over filled. Head gasket or rings.

Run the valves and check compression. 180 and 210 is very high. Valves might be too loose. Maybe a partial missing cam lobe super wear issue? 210psi is around 14.7:1 compression. As in drag racing motor compression.

Been mowing on the ski slopes any?

Click to expand...

Actually 180 is within the 15% of of the minimum compression for this engine per the service manual. Other than the minimum spec for this engine of 160 psi, both cylinder must be within 15% of each other.

Now the first set of numbers are concerning as 110 and 210 are way out of spec if this one vs the other at the same time.

Smoke is coming out of the oil filler spout. It has 725 hours on it.

As per post 4 .
Off with the head.

I am unfamiliar with this valve system. To take the bolts out the rocker arms will have to come off. Apparently there is no valve adjustment on this one?
Does the head just go back on with no adjustments?

StarTech said:

Actually 180 is within the 15% of of the minimum compression for this engine per the service manual. Other than the minimum spec for this engine of 160 psi, both cylinder must be within 15% of each other.

Now the first set of numbers are concerning as 110 and 210 are way out of spec if this one vs the other at the same time.

Click to expand...

I have to take your word on it StarTech. That is racing gas territory 180-210psi. Something like 110 octane.

Most mower engines are rated at 8:1 or 8.5:1 static compression. What are these rated at?

Is the manual calling it dynamic compression? That is the only believable scenario I can swallow. Tiny little cams pumping up cylinder pressure.....

I found a video which helps. There is oil dripping out of the lower bolt head. A little trouble getting it off.

Hydraulic lifters.

ba_50 said:

I am unfamiliar with this valve system. To take the bolts out the rocker arms will have to come off. Apparently there is no valve adjustment on this one?
Does the head just go back on with no adjustments?

Click to expand...

Yes, just remove the pivot bolt / nut in the middle

Is this one leaking? Can rings be worn out in 750 hours?

Is this plate the oil breather?