# Honda GC190A -No Compression!!!



## Tamfan (Jun 20, 2010)

I'm working on a Honda CC190A Engine thats on a Excell Pressure Washer that has no Compression.

It's a Honda GC190
SN stamped on unit is GCAAA-1045349 Type is QHAD

I did a Cylinder Leakdown Test on it and air blows through the exhaust and out the muffler. 

I'm not that familiar with Honda's since I work primarily in Briggs and Tecumsehs. 

I have to believe there is some sort of "decompression device" that is causing the exhaust to stay open to much and not allowing any compression reading.
I'm I anywhere close in my thinking on this? 

I was told this unit was doing fine before and suddenly it was unable to be started, and the customer told me after removing the plug themselves they could not get any compression.

I welcome any help you folks can offer!
Thanks, PL


----------



## 30yearTech (Sep 14, 2006)

It's probably a stuck valve, you may need to pull the valve cover off and have a look, may just need a little carb. cleaner sprayed on the valve stem to clean it up.


----------



## Tamfan (Jun 20, 2010)

30yearTech said:


> It's probably a stuck valve, you may need to pull the valve cover off and have a look, may just need a little carb. cleaner sprayed on the valve stem to clean it up.


I'll give that a try and let you know. Thanks!


----------



## Tamfan (Jun 20, 2010)

Tamfan said:


> I'll give that a try and let you know. Thanks!


Hey 30 Year Tech, 
I want to thank you for your help!

It was a stuck Exhaust Valve and sticky Auto Decompression Mechanism on the Camshaft/Top Belt Gear.

Used Carb Cleaner and worked Valve Stem and shaft over with a good cleaning and cleaned the guide. Lubed up with assembly lube real good and changed oil. New Valve cover sealant and all is good now.

It starts good and seems to run great. Only crazy thing I can't figure out is when I did a compression test afterwards, it only procuces 70-75 PSI.

Thanks for your help again 30yr!

Paul


----------



## 30yearTech (Sep 14, 2006)

Tamfan said:


> Hey 30 Year Tech,
> I want to thank you for your help!
> 
> Only crazy thing I can't figure out is when I did a compression test afterwards, it only procuces 70-75 PSI.
> ...


Your welcome Paul.

Due the mechanical compression release, you will not get an accurate compression reading at cranking speeds. The compression release will deactivate once the engine starts running and rpm's increase, then you will get full compression.


----------



## Tamfan (Jun 20, 2010)

30yearTech said:


> Your welcome Paul.
> 
> Due the mechanical compression release, you will not get an accurate compression reading at cranking speeds. The compression release will deactivate once the engine starts running and rpm's increase, then you will get full compression.


Thanks! That makes sense. I have more reassurance now and will return the unit to the customer. 

You have helped me many times 30 Year, and I truly appreciate you helping us when we're at a standstill. 

Thanks, again!
Paul


----------

