ANYONE?!

My step dad said between 160-180 is good. But I can't find it anywhere.

Testing it hopefully tomorrow.

 

Front cylinde[
345 - 590 kPa (3.5 - 6 kg/cm2, 50 - 85 psi)

Rearc ylinder
685 - 1080 kPa (7.O - 11 kg/cm2, 110 - 156 psi)

Warm up the engine thoroughly.
Stop the engine.
Removeo ne sparkp lug and attach the compression
gauge and adapter firmly into the spark plug hole. Do
not remove the other spark plug onlyt he plug lead.
For the other cylinder remove both spark plugs

using the starter motor, turn the engine over with the
throttlef ully open until the compression gauges tops
rising the compression is fhe highest reading obtainable

Repeat the measurement for the other cylinder.

NOTE
lf the engine is well broken in. the crcnking speed may
become fastet shutting down the decompressor. This
can raise the ftont cylinder comprcssion pre\ture near
to the rcar cylindels in some engines.

 

Brian - Those numbers are high even for sea level. Maybe for the Dead Sea <g>.

Ratsastaja - Where did you get those numbers? Wouldn't it be closer to 900kPa for the maximum assuming 9.0:1 compression ratio?

 

Ratsastaja - Where did you get those numbers? Wouldn't it be closer to 900kPa for the maximum assuming 9.0:1 compression ratio?

From original vn 1500 service manual.

 

Had a factor missing. Yeah, I get about 160 PSI for a rough rule of thumb for an engine in perfect condition at standard conditions. I am curious as to why the front cylinder spec is so low from the manual. Delayed intake opening to resist strain on the starter?

 

NOTE
lf the engine is well broken in. the crcnking speed may
become fastet shutting down the decompressor. This
can raise the ftont cylinder comprcssion pre\ture near
to the rcar cylindels in some engines.

There is decompressing mechanism in both camsafts but they do not open exhaust valves symmetricaly. If you remove mechanism from both camsafts u get even pressure

 

Front (Cylinder 1) PSI was ~130, then I added a cap of oil and it measured 140
Cylinder 2 was 140, then 150 when I added a cap of oil.

I think the reason they're different is because Cylinder 1 doesn't have a muffler, so no back pressure, Cylinder 2 does have a muffler.

I'm guessing this is the difference between the 2 cylinders.

Should I be concerned if they are measuring ~140-150?
Also should I be concerned about the pressure going up 10PSI? Is this a ring/valve issue or is it normal?

 

When doing test did you follow post#3 or how did you do test?

 

Are you having problems that have you doing a compression test?

 

The engine was just running really weak.

Oil change, new oil filter, gear shaft oil change, and 2/4 new spark plugs. Feels like its putting out about 10% more power already.

I'm guessing with a carb cleaning (and tuning), new exhaust, new fuel filter, the other 2 spark plugs it'll run great.

If it comes down to it after all that I guess I can get inside the engine and clean it out.

 

I only removed the spark plug I was testing. Tested cylinder #1, then #2, then added a cap of oil, sloshed it around, then tested #1 again, then repeated for #2.

 

I got 160 psi in both cylinders when it was cold in my Vulcan 1500. Bad news is it is burning oil and now blowing oil all over my pants. I don't know if i want to bring it in or try fixing it myself. Too cold out now to get into the garage.