compression spex and check.. wet or dry

**rally4x4racer** · 01-08-2007, 01:19 AM

According to the specifications page and the haynes manual I should be seeing about 180 PSI compression on my 1983 110.

I went and checked earlier and I got about 100-110 on the 4th pull when dry.
I put a tablespoon (or half quart) in the cyl and checked it again reading almost 200 PSI.

Are the specs for a wet test?
If not I got a prob

**Erics350x** · 01-08-2007, 08:55 AM

dry i would imagine. try running it up to temp first.

**rally4x4racer** · 01-09-2007, 01:22 AM

going once.....

will check it next time i ride it too Eric - shes blocked in by a couple projects...
(Im scatterbrain'd)

**troy** · 01-09-2007, 02:36 PM

i don't know if this aply's to 2 strokes but your suppost to hold the throttle in the wide open state while testing the compression. but first you should run your engine for 10 to 15 minutes then do a compression check.

some one will correct me if i'm wrong.

I'v never really did a compression test on a 2 stroke.

**daputz** · 01-09-2007, 03:28 PM

Normally you test the engine cold, unless specified in the manual.

The dry vs wet is a way to tell if it is the ring or valves on a 4 stroke. Take your 1st measurement dry (compare to spec in manual) then add the oil, if the compression greatly increases the rings are on the way out...................if the compression stays the same with the oil added the you have valve issues.

**Bryan Raffa** · 01-09-2007, 03:51 PM

yes cold and with the throttle open

**rally4x4racer** · 01-10-2007, 02:23 PM

ok -
this is a fresh bore with new piston and rings. any idea why it would be so low?

I will check it again with the throttle open when i get a chance - but what does that do? alow more air into the intake valve?

you reckon i did not break it in right and ruined the rings? thanks

**MathGSR98** · 01-10-2007, 02:35 PM

If you have put a new piston and rings in it and you still get a low compression reading, maybe your cylinder wall is scratched or there is something wrong with your valves. Does it run great?

**MTS** · 01-10-2007, 03:38 PM

110's dont have much compression-even new......i woudlnt worry about it, if it runs fine.

**rally4x4racer** · 01-10-2007, 05:17 PM

yea - it runs fine - but it is a little slow. I figured if it was not making enough compression that might slow it down some... ( but I have not ridden a 110 for 10+ years until I built this one from *Edited**Edited**Edited**Edited**Edited**Edited**E dited* parts)
both the dry and wet test showed absolutely no leakdown in a 20-25 minute timeframe - so I would assume the valves are good. they are brand new as well..

**rally4x4racer** · 01-10-2007, 05:18 PM

the word that got editied was an adjective for a person with no father... lol - I didnt know I could not say the b word!

**thefox** · 01-10-2007, 07:13 PM

Yes cold dry and with the throttle wide open. Opening up the throttle all the way will give you a lot more air; you should see the compression reading go up significantly. As for the 110 being slow, well that is why they made bigger machines, the 110 is a good machine and does lots of things well but going fast is not one of them (or at least in stock form).

**rally4x4racer** · 01-10-2007, 07:21 PM

ha - thanks fox... you just shattered my dreams!!

its not totally stock! I have that super badass cobra exhaust on it - lol

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compression spex and check.. wet or dry