Briggs and Stratton 675is Engine Jamming

[NigelJBlake]

Hi,I'm new to this site and I've been trying for a week to try and see how to put a question on here. Could someone give me some guidance please or have I just accomplished it. Cheers

[Mick]

or have I just accomplished it.

You have indeed.    Welcome to TGMForum.

[NigelJBlake]

Hi all, I've got a Briggs and Stratton 675is engine on my mower and when I push the button to start it it's almost like the engine fires then jams. Does anyone have any idea of what's going on or a remedy. I've bought plenty of non runners in the past to fix up and move on but never encountered this. I've already checked the clearances on valves, coil even spark plug and had the sump off and checked the timing marks. Hopefully someone knows. Cheers

[Mick]

Hi all, I've got a Briggs and Stratton 675is engine on my mower and when I push the button to start it it's almost like the engine fires then jams. Does anyone have any idea of what's going on or a remedy. I've bought plenty of non runners in the past to fix up and move on but never encountered this. I've already checked the clearances on valves, coil even spark plug and had the sump off and checked the timing marks. Hopefully someone knows. Cheers

If you remove the spark plug does it feel ok when turning by hand?  The InStart engines are known for making a strange noise almost like the starter is trying to knock the engine around, and that's caused by a faulty wiring harness on the engine.

[NigelJBlake]

If you remove the spark plug does it feel ok when turning by hand?  The InStart engines are known for making a strange noise almost like the starter is trying to knock the engine around, and that's caused by a faulty wiring harness on the engine.

Everything mechanical seems fine except after trying to start it several times it can sometimes jam the starter motor cog. I'll look into the getting a wiring harness. Cheers for the reply.

[Mick]

You can sometimes get around the harness issue by tightening up all the connectors, though this might be temporary it would at least confirm if it's your issue.  Could you perhaps post a photo of the wiring around the starter and back of the engine.

PS: I'll move your posts to their own topic.