Compression testing a GBV345 leaf blower

[Blubarb]

Hi all.

Is it possible to use an automotive compression tester on a small 25cc leaf blower motor, in this case a McCulloch GBV345 blower.

I have heard that without a Schrader valve at the end of the adapter that goes into the spark plug hole you will get a situation where the tube acts as part of the cylinder volume and thereby giving a much lower reading.

Can I simply do something simple like double the reading or am up for a new compression tester? Perhaps some adapter?

Appreciate any ideas and thoughts.

 

[StarTech]

Due the small volume you must use one with valve at the cylinder end. One problem is there is not volume to co301mpress to open the valve. Second compression tester use automobile engine also have a less sensitive valve so it take more volume and pressure to open it correctly.

I have been using an Actron compression gauge setup for years here that is correctly up for testing small engines.

 

[Blubarb]

T

Due the small volume you must use one with valve at the cylinder end. One problem is there is not volume to co301mpress to open the valve. Second compression tester use automobile engine also have a less sensitive valve so it take more volume and pressure to open it correctly.

I have been using an Actron compression gauge setup for years here that is correctly up for testing small engines.

Thanks

 

[StarTech]

I think the closest version currently on the market is the Actron CP7828A as my Actron kit is over ten years old now.

You do need one with the 10mm plug adapter as many newer 2 cycle engine is using the 10mm now.

 

[Tiger Small Engine]

Hi all.

Is it possible to use an automotive compression tester on a small 25cc leaf blower motor, in this case a McCulloch GBV345 blower.

I have heard that without a Schrader valve at the end of the adapter that goes into the spark plug hole you will get a situation where the tube acts as part of the cylinder volume and thereby giving a much lower reading.

Can I simply do something simple like double the reading or am up for a new compression tester? Perhaps some adapter?

Appreciate any ideas and thoughts.

McCullough went out of business about 23 years ago, so we are obviously talking about an older blower. Best thing to do if you suspect low compression on handheld equipment is to pull the muffler and look at condition of the piston, rings, and cylinder. Problem is without experience reading the amount of scoring, it is sometimes difficult to determine.

 

[StarTech]

Just note this is the same model as the Poulan/Weedeater GBV345 which is basically a Husqvarna machine. 14mm spark plug.

Just note that if the OP has a compression lower than 100 psi it already beyond economical repair.