Assuming all things are equal and have been interchanged with no difference the only thing i can suggest is valve clearances or possibly one has been overheated somewhere along the way. Do they both spin freely and easily with spark plugs removed?

Portal Box 6

Entire Thread
Subject	Posted By	Posted
starting lawnmowers	seanw	14/05/15 10:12 PM
Re: starting lawnmowers	bigted	15/05/15 01:02 AM
Re: starting lawnmowers	aussietrev	15/05/15 01:52 PM
Re: starting lawnmowers	Dieselboy	15/05/15 09:11 PM
Re: starting lawnmowers	seanw	15/05/15 09:19 PM
Re: starting lawnmowers	bigted	16/05/15 02:07 AM
Re: starting lawnmowers	seanw	16/05/15 05:45 PM
Re: starting lawnmowers	bigted	16/05/15 07:01 PM
Re: starting lawnmowers	seanw	16/05/15 09:11 PM
Re: starting lawnmowers	Blumbly	16/05/15 11:42 PM
Re: starting lawnmowers	seanw	17/05/15 12:20 AM
Re: starting lawnmowers	seanw	17/05/15 12:29 AM
Re: starting lawnmowers	Gizmo	17/05/15 10:04 AM
Re: starting lawnmowers	seanw	17/05/15 10:22 PM
Re: starting lawnmowers	Gadge	18/05/15 08:38 AM
Re: starting lawnmowers	Deejay	18/05/15 09:13 AM

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